Stick a post-it on your old VLB card stating 'possibly defective serial ports - re-evaluate when feeling on top of the world'. Then set the card in your box of defective PCB's. That's what I do.

The post-it is essential. Without it, in 5 years, you're memory on the issue will be foggy, if not nil. You may list it on eBay, forgetting the defect/anomaly, and you'll have an unhappy customer.

feipoa wrote on 2026-07-03, 23:01:

Stick a post-it on your old VLB card stating 'possibly defective serial ports - re-evaluate when feeling on top of the world'. Then set the card in your box of defective PCB's. That's what I do.

The post-it is essential. Without it, in 5 years, you're memory on the issue will be foggy, if not nil. You may list it on eBay, forgetting the defect/anomaly, and you'll have an unhappy customer.

That's amazing, that's just what I've done. Except I had the antistatic bag that the replacement arrived in, so I've stored it in that and wrote my errata. Great minds think alike!

Mockingbird was kind enough to send me a board to try, but I haven't successfully gotten it to work. I'd like to leave my serial port on my VLB board as COM1 and use this as COM2. I've jumpered IRQ5 as I know it's unused and bridged the 2 top-left pins for COM2. Are there specific drivers, or will mouse.exe work? I'm currently using v9.00 driver, but cannot get it working in either DOS or WINDOWS 3.11. I'm using a generic Compaq PS2 ball mouse, what drivers should be used in Windows especially?

I've just noticed on the back the default IRQ for each COM port, is there a way to check COM port usage in DOS? My BIOS is a very old and very barebones AMIBIOS from 1993.

ldeveraux wrote on 2026-07-25, 23:35:

Mockingbird was kind enough to send me a board to try, but I haven't successfully gotten it to work. I'd like to leave my serial port on my VLB board as COM1 and use this as COM2. I've jumpered IRQ5 as I know it's unused and bridged the 2 top-left pins for COM2. Are there specific drivers, or will mouse.exe work? I'm currently using v9.00 driver, but cannot get it working in either DOS or WINDOWS 3.11. I'm using a generic Compaq PS2 ball mouse, what drivers should be used in Windows especially?

I've just noticed on the back the default IRQ for each COM port, is there a way to check COM port usage in DOS? My BIOS is a very old and very barebones AMIBIOS from 1993.

CuteMouse can do custom IRQs in DOS and wndows 3.11 has the ability to change the location of COM2

https://ps-2.kev009.com/pcpartnerinfo/ctstips/5bbe.htm

If COM2 is disabled on the VLB card and the motherboard does not have built in serial ports, IRQ3 should be clear to use which is the default. With IRQ3 you should be able to use any mouse driver you want.

NeoG_ wrote on 2026-07-26, 01:12:

CuteMouse can do custom IRQs in DOS and wndows 3.11 has the ability to change the location of COM2 […]
Show full quote

ldeveraux wrote on 2026-07-25, 23:35:

Mockingbird was kind enough to send me a board to try, but I haven't successfully gotten it to work. I'd like to leave my serial port on my VLB board as COM1 and use this as COM2. I've jumpered IRQ5 as I know it's unused and bridged the 2 top-left pins for COM2. Are there specific drivers, or will mouse.exe work? I'm currently using v9.00 driver, but cannot get it working in either DOS or WINDOWS 3.11. I'm using a generic Compaq PS2 ball mouse, what drivers should be used in Windows especially?

I've just noticed on the back the default IRQ for each COM port, is there a way to check COM port usage in DOS? My BIOS is a very old and very barebones AMIBIOS from 1993.

CuteMouse can do custom IRQs in DOS and wndows 3.11 has the ability to change the location of COM2

https://ps-2.kev009.com/pcpartnerinfo/ctstips/5bbe.htm

If COM2 is disabled on the VLB card and the motherboard does not have built in serial ports, IRQ3 should be clear to use which is the default. With IRQ3 you should be able to use any mouse driver you want.

I think I've disabled serial 2 on my VLB, but no matter what I do in Windows, I can't change the port address for the card. it defaults to 02E8 and changes will not stick. Even setting COM2 to default, after a restart it's back to 02E8. Any way to get the card to use that port address?

ldeveraux wrote on 2026-07-25, 23:35:

Mockingbird was kind enough to send me a board to try, but I haven't successfully gotten it to work. I'd like to leave my serial port on my VLB board as COM1 and use this as COM2. I've jumpered IRQ5 as I know it's unused and bridged the 2 top-left pins for COM2. Are there specific drivers, or will mouse.exe work? I'm currently using v9.00 driver, but cannot get it working in either DOS or WINDOWS 3.11. I'm using a generic Compaq PS2 ball mouse, what drivers should be used in Windows especially?

I've just noticed on the back the default IRQ for each COM port, is there a way to check COM port usage in DOS? My BIOS is a very old and very barebones AMIBIOS from 1993.

You're welcome, and I've got another card if anyone else needs one.

According to the CuteMouse documentation, you need to initialize with this:

CTMOUSE /S25

If it detects it and installs it, run something like EDIT to check if the mouse cursor is present and working.

ldeveraux wrote on 2026-07-26, 12:55:

I think I've disabled serial 2 on my VLB, but no matter what I do in Windows, I can't change the port address for the card. it defaults to 02E8 and changes will not stick. Even setting COM2 to default, after a restart it's back to 02E8. Any way to get the card to use that port address?

The standard assignments are:
COM1: 3F8h, IRQ 4
COM2: 2F8h, IRQ 3
COM3: 3E8h, IRQ 4*
COM4: 2E8h, IRQ 3*
* any program worth its salt that accepts COM3: or COM4: will also allow specifying a custom IRQ.

At POST, your BIOS probes the four possible COM ports and saves them in the BIOS Data Area. To dump the ports it has recorded in the BIOS data area, run:
DEBUG
D 40:0 L 8
Q

Due to endianness, the port addresses will be reported backwards, i.e. F8 03. Unpopulated ports will be 00 00.

If you've left a "gap" in the physical serial cards you have in your system, e.g. 3F8 on your i/o card and 2E8 on your mouse card, you can create this situation where the COM1: is 3F8 and COM2: is 2E8. This will be hopelessly confusing, so change the card that is jumpered for 2E8 to be 2F8 and IRQ 3.

jakethompson1 wrote on 2026-07-27, 01:10:

ldeveraux wrote on 2026-07-26, 12:55:

I think I've disabled serial 2 on my VLB, but no matter what I do in Windows, I can't change the port address for the card. it defaults to 02E8 and changes will not stick. Even setting COM2 to default, after a restart it's back to 02E8. Any way to get the card to use that port address?

If you've left a "gap" in the physical serial cards you have in your system, e.g. 3F8 on your i/o card and 2E8 on your mouse card, you can create this situation where the COM1: is 3F8 and COM2: is 2E8. This will be hopelessly confusing, so change the card that is jumpered for 2E8 to be 2F8 and IRQ 3.

I'm a bit out of my element here. Are you saying that I've forced the card to use 2E8 somehow? I know for certain I've selected COM2 on the board. I'll check the IRQ assignments when I'm home, thanks!

I've actually gotten the card working gangbusters by disabling COM1 on my VLB , using the serial mouse as COM2, setting this card as COM3. My PC is so strange, when I check it in MSD, it doesn't register COM3 as in use. I have a Compaq ball mouse working with the PS2 port, how would I get a Logitech optical mouse working? Every time I try changing the mouse in Windows Setup from Microsoft, or IBM PS/2 to Logitech, Windows won't boot.