Your Next Level of Support - User contributions [en]

AS/400 System Passwords

2026-05-04T20:26:29Z

Jgeorge44: known technical details of as/400 system password generation

In the AS/400 World, what is a "System Password"?

TODO: Brief Summary of what a password is, and what it's used for.

What we know about the password mechanism, and the triggers. Taken from one of many Discord Chats where I've explained what I know.

Don't think of "system passwords" as passwords in the normal context. The mechanism is basically a quorum check at IPL - the machine compares a known set of parameters (the system model number, serial number, load source disk serial number, and processor type) against three places where that information is stored - the MFIOP/SP, the control panel, and the load source disk. As long as at least 2 out of the 3 locations match, the machine assumes it hasn't been tampered with, and IPLs properly (and makes sure the 3 locations are in sync, if one was different). This allows you to replace one of those components in a machine repair without triggering the quorum failure.

The "password" used here is generated by IBM in response to values the machine shows that you need to give to IBM to reset this condition. The password isn't really a "password" like in normal usage, it's not stored anywhere, but when you enter this password into the machine, the machine validates the password against the system values in the machine (model, serial, etc) and then "resets" the 3 locations to the current system configuration and un-flags the system password prompt.

Basically the system password is a hash of the model, serial, and so on, and the machine validates that hash and presumes if IBM gave you that password back that you have satisfied whatever criteria IBM needed to give you the password (paying for a new processor class of OS license, or something else monetary back in the day). Nowadays you CAN wheedle a password out of IBM if you trigger one on a machine but it's slow (several months) and somewhat fragile of a process (lots of emails, explanations, and some praying to a good $DEITY or three)

Way Back When in the "Way Back When Days™" you could upgrade AS/400s simply by replacing processor boards, 3rd party marketers would, well, do precisely that, and then IBM would get shorted the upgrade costs and typically OS license costs, so they implemented the system password mechanism to more or less punish people from doing this, or at least make sure they paid IBM a fee for the privilege - system passwords used to cost money. The processor card serial number is actually not used in the password triggering mechanism (as far as I've ever been able to tell) but it's listed there so IBM could look up the original source of the processor card (by what machine it went into when it was first built) to determine how "gray" the gray market was that the sketchy upgrade came from.

I know a lot about how this process works because the reseller I used to FE for was the largest source of 3rd party AS/400 upgrades and was largely the reason these system passwords were put in place in the first place 🙂

Q: do we know more about how that hash (or whatever) and where exactly it is stored inside MFIOP/SP, the control panel, and the load source disk? like... in the control panel, is it a simple EEPROM or something more intricate?

This "hash" is never stored on the machine, the data used to trigger the password is stored pretty much plain text in all locations - the hash uses that data, and some encryption key hidden in SLIC somewhere - to validate the configuration. Think of it more as a digitial signature - hash(input data) is generated within the machine (at that screen above) and compared to the password provided by the user. if the hashes match, then everything is reset. the hash itself is never stored anywhere. We know (well, I'm 99.999% certain we know) THAT its stored in those three places, but WHERE exactly isn't completely known. The control panel has battery-backed RAM in it (in addition to the TOD clock) so presumably the data is stored in that RAM. We have no idea where it's stored in the MFIOP/SP because it's not documented really well enough for us to know, and there's no visible flashprom chip on any of the boards that we've seen. It's stored on the load source disk, and there are a couple of places where the data can be found, but no real experimentation on if those values could be altered successfully.

In theory you should be able to alter that data on the load source disk, and in the control panel RAM, and upgrade hardware without triggering a password, but there's not been any attempt at that as far as I know because you basically get one chance to do it right before you trigger the actual password mechanism, and I know IBM can be wheedled out of a system password once, but I'm pretty sure they wouldn't do it for the same machine for multiple attempts

Anyhow, thats all anyone knows about the system password functionality that are willing to speak publicly about it 👀

Comment: It must have some way to restore the data into the control panel then because I had 0000BBBB and like 0.3V on the planar battery.

Yes. if the MFIOP and load source disk match the control panel is rewritten without incident
also you can replace the load source disk and the system will tell you that the load source disk is different (and give you the OLD serial number, stored in these areas) and let you "approve" the load source change, which then updates the config data with the new serial number
you can replace any one of those 3 componets, one at a time, without triggering the password

What makes CISC machines notoriously more touchy about this is that older OSes with the first incarnations of the system password trigger were WELL known for false triggers, and sometimes would trigger a system password on the machine from OS upgrades, or from other non-trigger hardware upgrades (memory, more I/O, etc) because the trigger mechanism was buggy and overly paranoid
by the time RISC machines came about the triggers were less paranoid, and mostly legitimately triggered when they were needed, though not always - but significantly less than the number of false triggers in CISC machines and like V2R2 and V2R3

Comment: You know, this is deserving of a blog post of some sort

jgeorge: I should write it down somewhere instead of typing it all up all the time

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-06T21:13:48Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or

- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old

- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip

- Some solder (fine electronic rosin-core solver of almost any type)

- Chip-Quik SMD Removal kit (optional, but helpful)

- One 28 pin DIP chip socket (of the "square pin" variety)

- One programmable ROM chip of the 2764/27128/27256 type or any equivalent

- A way to program the aforementioned PROM

- Some fine wire, 28-30 gauge

- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver

- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

[[File:54IDPROMaltered.jpg|480px]]

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg|480px]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy

0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes add up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400

0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png|480px]]

Your final modification should look something like this:

[[File:5494lancardfull.jpg|480px]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

[[File:5494lancardid.jpg|480px]]

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:51:20Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or

- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old

- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

[[File:54IDPROMaltered.jpg|480px]]

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg|480px]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy

0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes add up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400

0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png|480px]]

Your final modification should look something like this:

[[File:5494lancardfull.jpg|480px]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

[[File:5494lancardid.jpg|480px]]

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:27:58Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old

- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

[[File:54IDPROMaltered.jpg|480px]]

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg|480px]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png|480px]]

Your final modification should look something like this:

[[File:5494lancardfull.jpg|480px]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

[[File:5494lancardid.jpg|480px]]

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:26:57Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

[[File:54IDPROMaltered.jpg|480px]]

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg|480px]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png|480px]]

Your final modification should look something like this:

[[File:5494lancardfull.jpg|480px]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

[[File:5494lancardid.jpg|480px]]

TODO: I have pics to upload still sorry

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:26:33Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

[[File:54IDPROMaltered.jpg|480px]]

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg|480px]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png|480px]]

Your final modification should look something like this:

[[5494lancardfull.jpg|480px]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

[[File:5494lancardid.jpg|480px]]

TODO: I have pics to upload still sorry

File:5494lancardfull.jpg

2024-12-05T22:25:22Z

Jgeorge44:

File:5494lancardid.jpg

2024-12-05T22:24:26Z

Jgeorge44:

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:22:09Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

[[File:54IDPROMaltered.jpg|480px]]

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg|480px]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png|480px]]

Your final modification should look something like this:

[[File:5494finalmod.jpg|480px]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

TODO: I have pics to upload still sorry

File:5494finalmod.jpg

2024-12-05T22:20:31Z

Jgeorge44:

File:5494modifiedsocket.jpg

2024-12-05T22:16:13Z

Jgeorge44: Jgeorge44 uploaded a new version of File:5494modifiedsocket.jpg

File:54IDPROMaltered.jpg

2024-12-05T22:14:44Z

Jgeorge44: Jgeorge44 uploaded a new version of File:54IDPROMaltered.jpg

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:14:05Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

[[File:54IDPROMaltered.jpg]]

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

TODO: I have pics to upload still sorry

File:54IDPROMaltered.jpg

2024-12-05T22:13:09Z

Jgeorge44:

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:10:58Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[File:5494modifiedsocket.jpg]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

TODO: I have pics to upload still sorry

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:10:31Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

[[5494modifiedsocket.jpg]]

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

TODO: I have pics to upload still sorry

File:5494modifiedsocket.jpg

2024-12-05T22:09:57Z

Jgeorge44:

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:07:45Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[[File:5494romchecksum.png]]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

TODO: I have pics to upload still sorry

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:07:26Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[File:5494romchecksum.png]

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

TODO: I have pics to upload still sorry

File:5494romchecksum.png

2024-12-05T22:06:39Z

Jgeorge44:

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T22:05:56Z

Jgeorge44:

The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions:

- It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or
- It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35).

IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is electrically identical to the IBM LAN Adapter/A for Ethernet, supported in PS/2 systems. However the Microchannel Card ID is different between the 5494 card and the PS/2 card, so putting a PS/2 LAN Adapter in a 5494 will not work.

The 5494 version of this LAN card nowadays is EXTREMELY rare. The PS/2 version of the same hardware is relatively obtainable still.

In researching the differences between the two cards, we discovered that the only difference between the two cards is the Microchannel Card ID, and discovered that it is possible - with some effort - to "renumber" a PS/2 LAN card to work in a 5494.

There are two PS/2 LAN card versions:

- A "long" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_A-Old
- A "short" card: https://www.ardent-tool.com/NIC/LAN_A.html#LAN_Adapter/A

It is possible to modify these cards to work in a 5494 by programming a new ID PROM chip. The chip on these boards is a small PLCC-20 pin surface mounted component and is non-trivial to remove and replace. However, both cards have a socket for an RPL/BOOT ROM chip that carries all but one of the required board signals, and the boot ROM is not used for the 5494 and needs to be removed anyway.

The basic hardware modification is not trivial, but not insurmountable for anyone with some soldering skills.

You will need:

- A soldering iron with a fine tip
- Some solder (fine electronic rosin-core solver of almost any type)
- Chip-Quik SMD Removal kit (optional, but helpful)
- One 28 pin DIP chip socket (of the "square pin" variety)
- One programmable ROM chip of the 2764/27128/27256 type or any equivalent
- A way to program the aforementioned PROM
- Some fine wire, 28-30 gauge
- An X-acto knife with a pointed blade or an extremely small bladed flat tip screwdriver
- Hot Glue Gun (optional, but recommended)

Step 1: Remove the RPL/BOOT PROM from the board. It's the large 28 pin chip in the socket.
PRO-TIP: You won't need this ROM anymore and it's the right type for this modification, so if you have an EPROM eraser, erase this chip and you can reuse it.

Step 2: Find U5 on the PCB. It's a small square chip. On the short LAN card its directly above the ROM socket. On the long card it's near the crystal along the top edge of the board. The chip has a part number sticker on the top of it, and it's IMPORTANT to note its orientation on the board - the chip has a beveled edge on one edge. That edge is "upright" on the short board, and the bevel is on the "right" side of the chip on the long card.

Step 3: Use an X-Acto knife with a pointed blade, or some other extremely small blade or screwdriver to get under the leg of the chip that is FARTHEST TO THE RIGHT along the beveled edge of the chip. Heat that one pin with a soldering iron, and when it's hot, gently pry the pin out from under the chip and off the board. The pin curls under the chip somewhat, so the lead is a little longer than you would expect. Make sure the pin on the chip is well clear of the board and pads. Repeat this step with the SECOND RIGHTMOST PIN along that same edge. When you are done you'll have three pins on the beveled edge of the chip still in place and the two pins on the right clear of the board. If you have any Chip-Quik, a little of the flux and solder in that kit will make lifting these 2 pins significantly easier, but it's doable without it.

Step 4: Strip and tin the end of a piece of fine gauge wire. For the long board the wire should be at least 6 inches for the short board the wire should be about 2 inches. It'll need to reach the 28 pin socket on the board, and you can trim it later, don't be stingy. Clip the tinned and exposed portion to only 1-2mm of exposed wire, and solder it to the RIGHTMOST PAD on the BOARD, under the pin you removed. Be careful to not bridge the wire to the other exposed pad or any other pins or the pins you lifted from the board. This takes a little bit of a steady hand, the pad on the PCB is very small. Leave the other end of the wire, we'll come back to it later.

Step 5: Using a small pair of needle nose pliers or some other tool, use the tool to "push" the following pins up from the bottom of the DIP socket to remove them from the plastic holder. This disconnects the unneeded pins on the BOOT PROM socket from the modified ID PROM that's going to take its place. Remove pins 1, 2, 3, 4, 5, 6, 21, 23, 24, 25, 26, and 27. BEND pins 20 and 22 90 degrees to the outside of the socket so the pins are exposed out of the side of the socket.

Step 6: Insert the modified socket into the BOOT PROM socket on the board, lining up the Pin 1 markings on the board. Route the wire you connected under the ID PROM to the socket and solder it to the two pins sticking out of the side of the socket (pins 20 and 22 from the previous step).

Step 7: Optional but recommended: Use a hot glue gun to tack down the patch wire to the board, and a bead of hot glue to stick the modified DIP socket onto the socket on the board. Be sparing - a little hot glue goes a LONG way!

Step 8: Program the new ID PROM. Open your favorite ROM programming software, set the device type to the ROM you're going to program (the BOOT PROM, if you're reusing that one, is a 27128). Clear the buffer in the software and enter the following 32 bytes into the ROM buffer starting at address 0x0000:

0x0000 E6 FE 00 06 29 xx xx xx 00 00 00 00 00 00 5A yy
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

IMPORTANT! Replace the 'xx xx xx' above with the last 3 bytes of the Ethernet MAC address of the card (if you know it). If you don't know it, find the serial number label on the card and use the last 6 digits in the serial number. If you can't find that, pick your favorite 3 hex bytes and use that for an address.

ALSO IMPORTANT! Replace the 'yy' with the "8 bit checksum" for that line of bytes. The checksum number is the number that makes that line of bytes att up to a hex number ending in '00' - see http://easyonlineconverter.com/converters/checksum_converter.html for a quick calculator.

Here's an example of a "correct" ROM and it's checksum:

0x0000 E6 FE 00 06 29 05 96 82 00 00 00 00 00 00 5A 76 <- all these bytes add up to 0x400
0x0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Step 9: Insert the modified ROM into the modified socket, in the BOOT PROM socket on the PCB.

The board now can be installed in a 5494 and configured.

TODO: I have pics to upload still sorry

Making a PS/2 Ethernet Adapter work in a 5494

2024-12-05T21:23:10Z

Jgeorge44: Created page with " The 5494 Remote Control Unit supports a Microchannel Ethernet LAN Adapter. This adapter can provide two different functions: - It can connect twinax terminals (and PCs with twinax emulation cards) to 1-4 AS/400 systems connected to an Ethernet network; or - It can connect locally-attached Ethernet LAN systems to 1-4 AS/400 systems over the 5494's communication line 9V.24/X.21/V.35). IBM supports ONE specific Ethernet adapter in the 5494 - PN 10H4633. This card is elec..."

5494 Remote Control Unit

2024-12-05T21:02:15Z

Jgeorge44: Created page with " The 5494 Remote Control Unit is the last model in a series of Twinax terminal controllers for IBM Midrange systems. A lot of good info is already online at https://www.ardent-tool.com/5494/ This page will document more localized shenanigans to the controller that we've performed."

The 5494 Remote Control Unit is the last model in a series of Twinax terminal controllers for IBM Midrange systems.

A lot of good info is already online at https://www.ardent-tool.com/5494/

This page will document more localized shenanigans to the controller that we've performed.