Hi All,

I built one of these cards, so I signed up for the forum here to share my experiences.

The CPLD is the hardest part to solder. It's definitely doable without a hot air station if you use liquid flux, a good chisel tip on the iron, and solder braid to clean up bridges. I was able to program it using a Raspberry Pi and XC3sprog with the GPIO pins. I used a guide found here: https://anastas.io/hardware/2020/09/29/xc9500 … i-xc3sprog.html (not affiliated)

My system is a PS/2 Model 70 486. Its got a 486 DX-2 50mhz, 8MB ram, and also a Buslogic BT640 SCSI card and an IBM XGA-2 display card installed.

I did testing with both Dos 6.22 and Windows 3.11

Adlib games seem to work just fine under DOS. I had no issues whatsoever with several games. Trying to use digitized audio is when I ran into issues.

Doom works with SFX and music using address 220, IRQ 2, DMA 1. All other IRQ settings result in a "Transfer stack overflow" and lock up.

Simcity 2000 (DOS) locks up during installation when detecting the sound card no matter what IRQ settings are used.

Windows 3.11 locks up immediately after the startup sound plays. Only IRQ 3, 5, and 7 are supported by the SB MCA driver (sbmwu.exe) so I can't try IRQ 2 which works for Doom.

I think there is an IRQ conflict but I haven't been able to resolve it so far, even by removing all other MCA cards from the system. I'll continue to troubleshoot and share anything I found out here.

Edit: SBDIAG successfully plays digital audio with IRQ set to 2, 3, 5, and 7 as long as I configure the card to match in the system setup.

Wow, that's extremely cool. I wonder what's wrong that so much software crashes with IRQ not 2...? Are you sure that the card itself is completely ok?

EDIT: C92 looks crooked. Also I would triple check ALL solder joints.

root42 wrote on 2021-02-18, 07:34:

Wow, that's extremely cool. I wonder what's wrong that so much software crashes with IRQ not 2...? Are you sure that the card itself is completely ok?

EDIT: C92 looks crooked. Also I would triple check ALL solder joints.

I'm not sure why it's so weird about IRQs. I have been chatting with TubeTimeUS about it and we both think it looks like an IRQ conflict but I can't find any after going through the system configuration. I can't rule out some sort of assembly error or a problem with my particular PS/2 yet but I'll be working on it more when I have time.

A few updates regarding the issues I mentioned in the last post.

The Windows crash was fixed by using a driver provided for the Sound Blaster Pro MCV (CT5330). From the CT5330 installer readme:

STARTING MICROSOFT WINDOWS 3.1 IN ENHANCE MODE […]
Show full quote

STARTING MICROSOFT WINDOWS 3.1 IN ENHANCE MODE

Some of the PS/2 system may encounter a "BUS TIME-OUT" error when
starting Windows in enhance mode after bootup. We have included a
driver "VDMAD.386" to counteract this problem. The program
"WINSETUP.EXE" will copy this driver to your Windows \SYSTEM
sub-directory and change the following line under the [386Enh]
section in your SYSTEM.INI file.

[386Enh]
; change this line
DEVICE=*VDMAD
; to this line
DEVICE=VDMAD.386

Another workaround (also from the CT5330 readme) was to launch Windows in Standard mode and then exit and launch again in Enhanced mode. I had good luck with either of these fixes.

As for Doom and SC2000, both worked with IRQ 5 and 7 if I replaced the DOS4GW extender with DOS32A, although SC2000 is not compatible with the XGA2 and gets garbled graphics (but with working sound!). This one is a mystery to me but I'm guessing that DOS32A must handle interrupts differently than DOS4GW?

Also if anyone else wants to try building one of these, I do have a few extra boards that I'd be willing to sell. They are bare boards so assembly will be required. Just let me know.

Humm. So it does work in Windows 3.11. Very interesting indeed. I'd be interested in one of the boards.

MerrickD wrote on 2021-02-19, 02:33:

Also if anyone else wants to try building one of these, I do have a few extra boards that I'd be willing to sell. They are bare boards so assembly will be required. Just let me know.

Yes, please! I'll take one!

I was going to have some boards printed too but was wondering what I'd do with the extras...

MerrickD wrote on 2021-02-19, 02:33:

Also if anyone else wants to try building one of these, I do have a few extra boards that I'd be willing to sell. They are bare boards so assembly will be required. Just let me know.

Might be a little late but I'm definitely interested as well.

Hey guys, it looks like I can't reply to PMs on this forum yet. I have 4 boards left and I'd like to get $20 +shipping (each) for them. If you're still interested please send me an email. Thanks.

Edit: All my remaining boards are gone. Thanks!

MerrickD wrote on 2021-04-16, 21:57:

Hey guys, it looks like I can't reply to PMs on this forum yet. I have 4 boards left and I'd like to get $20 +shipping (each) for them. If you're still interested please send me an email. Thanks.

What's your email?

edit: email sent!