feipoa wrote on 2025-04-16, 12:57:

Has anyone has tried this mod on the v4 boards yet? The layout for the strapping resistors looks identical to v1-3 boards.

I'm happy to report that mkarcher's PS/2 mod also works on v4 motherboards.

feipoa wrote on 2025-04-18, 13:26:

I'm happy to report that mkarcher's PS/2 mod also works on v4 motherboards.

... however, you cannot use the eSupport BIOS. I was unable to get the 3.5" floppy to work with the eSupport BIOS, nor was I able to complete booting to the CF card. I needed to use the AUS26.ROM BIOS, which is a compressed WINBIOS with PS/2 mouse support for the v1-3 boards. The BIOS which comes with the v4 boards is a, presumably, newer AUS33.ROM without PS/2 mouse support.

Unfortunately, I noticed that some games don't do well with HOT-433 WINBIOSes and I am not sure why. I tested Super Street Fighter II Turbo (SSF2T) in DOS and the gameplay was incredibly slow. This is also evident if v1-3 is using WINBIOSes. Once I switch to the AWARD BIOS, SSF2T runs fine on v1-3. I don't know how this translates to other games.

feipoa wrote on 2025-04-19, 08:01:

feipoa wrote on 2025-04-18, 13:26:

I'm happy to report that mkarcher's PS/2 mod also works on v4 motherboards.

... however, you cannot use the eSupport BIOS.

Thanks for reporting. Are the BIOSes for rev 1-3 and rev 4 actually interchangable, or are there subtle differences requiring BIOS adjustments? Maybe the eSupport BIOS just doesn't match how some detail of the rev4 board works. The floppy issue is likely caused by the rev 1-3 using an UMC8663 Super I/O chip, while the rev 4 uses the later UMC8669 chip.

If there is no original Award BIOS for the rev4, someone likely needs to slice the Super I/O initialization code for the UMC8669 into the eSupport BIOS to get a BIOS that works fine on the rev4 without the performance issues you observed.

mkarcher wrote on 2025-04-19, 11:08:

Are the BIOSes for rev 1-3 and rev 4 actually interchangable, or are there subtle differences requiring BIOS adjustments? Maybe the eSupport BIOS just doesn't match how some detail of the rev4 board works. The floppy issue is likely caused by the rev 1-3 using an UMC8663 Super I/O chip, while the rev 4 uses the later UMC8669 chip.

I don't know.
v4 usually came with 433AUS33.ROM. My notes from 15 years ago mention this was the last BIOS for v4.
v1-3 usually came with 433AUS2C.ROM. My notes from the same era indicate this was that last BIOS for v1-3.

My notes also mention, "433AUS33.ROM works on v1-3".

433AUS26.ROM was the last WINBIOS for v1-3 with PS/2 mouse support, and when placed on the v4 motherboard, the floppy works fine. Curious.

On v4, I did not notice any performance difference between 433AUS33.ROM (no mouse support) and 433AUS26.ROM (with mouse support). This means that I also witnessed the SSF2T slowdown with the official v4 BIOS, 433AUS.ROM. There was no slowdown in DOOM or Quake.

I did a little more testing and noticed that certain graphics cards demonstrate very poor performance on WINBIOSes (AUS26/AUS33). For example, when I had the Rendition V2200 installed on v4, my DOOM scores were abysmal (12.6 fps). When I swapped the card for a Virge, DOOM jumped to 51 fps. The Rendition ran just fine with v1-3 using the AWARD eSupport BIOS. Perhaps there's similar graphics particularities with this WINBIOS and SSF2T.

mkarcher wrote on 2025-04-19, 11:08:

If there is no original Award BIOS for the rev4, someone likely needs to slice the Super I/O initialization code for the UMC8669 into the eSupport BIOS to get a BIOS that works fine on the rev4 without the performance issues you observed.

That would be nice! I don't think there was an AWARD BIOS for v4.

I only saw up to PIO-3 in the eSupport BIOS, while the WINBIOSes let you select up to PIO-4. This probably doesn't matter because IDE speed gets adjusted in config.sys using the UMC driver.

feipoa wrote on 2025-04-18, 13:26:

feipoa wrote on 2025-04-16, 12:57:

Has anyone has tried this mod on the v4 boards yet? The layout for the strapping resistors looks identical to v1-3 boards.

I'm happy to report that mkarcher's PS/2 mod also works on v4 motherboards.

I have made all modifications except I have used SN74LS05N and SN74HC05N instead SN7406N (I had them at home) and Jetkey V.5.0 but V4 does not post - I got 00 → C1 → 0C → C3 → 03 → 05 (the same was without Jetkey V.5.0 chip after removing and moving resistors)

I can confirm that JET KEY v3 and v5 will not work with PS/2. Did you try a KBC with PS/2 mouse support?

Like one of these:

Intel/Megatrends KB-BIOS-VER-F
Intel/Megatrends MEGA-KB-F-WP
Holtek HT6542B
VT82C42N
AMIKEY-2
Intel/Megatrends Megakey

The VT82C42N controllers are plentiful on eBay and cheap.

I saw it on eBay, but I searched for the ones available in my country, I found INTEL MBL8042H and JET KEY v5. And bought the second one. I have AMIKEY-2 on Pentium mainboard but it is soldered in. I think with Jetkey v.5.0 at least keyboard must work, I saw this chip were used in 486 motherboards

blacksn wrote on 2025-05-30, 10:57:

I think with Jetkey v.5.0 at least keyboard must work, I saw this chip were used in 486 motherboards

Sometimes it does, sometimes it doesn't. I remember testing this on a 386 board with, I think, JET KEY and the keyboard didn't even work once the PS/2 mod was done. Can you desolder the AMIKEY-2 with a solder sucker hand pump?

I put a NEC D80C42C from 386 and now system started but keyboard is not working, maybe the problem is that I used 7405 not 7406. I also put Jetkey v.5.0 into 386 - first time when I pressed DEL I got "8042 Gate A20 Error. System halted" but after reset I successfully entered BIOS and keyboard is working.

blacksn wrote on 2025-05-30, 14:41:

I put a NEC D80C42C from 386 and now system started but keyboard is not working, maybe the problem is that I used 7405 not 7406. I also put Jetkey v.5.0 into 386 - first time when I pressed DEL I got "8042 Gate A20 Error. System halted" but after reset I successfully entered BIOS and keyboard is working.

There are two different pin assignments for keyboads controllers. One is "AT style", and the other one is "PS/2 style". The 386 controller most likely only supports the AT-style pin assignment, and if you mod a HOT433 according to my instructions, you need a keyboard controller that supports the PS2-style pin assignment. Some keyboard-controllers may support both styles, and the JetKey v5 might be dual-protocol, but you would need to find out how to put the JetKey controller into PS2-style mode.

The failure of the keyboard with the NEC keyboard controller in the HOT board is clearly because that chip is programmed to support the AT-style pin assignment only. If your 386 system works with the JetKey installed, we can conclude that it supports the AT-style pin assignment, but we can't yet exclude that it can also be put into PS/2 mode by pulling some pin up or down.

keyboard type select:
pin33 of Jetkey BIOS to +5V via 1kΩ;
pin33 of Jetkey BIOS to GND

blacksn wrote on 2025-05-30, 16:13:

keyboard type select:
pin33 of Jetkey BIOS to +5V via 1kΩ;
pin33 of Jetkey BIOS to GND

This seems to be taken from 3 (+3 more) retro battle stations (or the document on The Retro Web that cites from there). It belongs to this board. It does not mention "controller mode", it mentions "keyboard type". As this is on a 286 machine, I'd guess this is about choosing between the XT and the AT keyboard protocol (on the keyboard side), not about the PS/2 controller pinout. It wouldn't make sense to let the user jumper the type of controller pinout, as the mainboard is designed for either the AT-style or the PS/2-style pinout. As that board does not have any way to connect a PS/2 mouse jack, that board is definitely designed for the AT-style pinout.

Bought VT82C42N, pS/2 mouse works fine.ThANKS!