The DTK PKM-0033S doesn't use the UM8881/8886, it uses a SiS 496/497. I've been working with this board over the past few days. I have hacked up the Zida Tomato 4DPS BIOS v1.72f to work on this DTK board. Now the DTK board seems to work with two 64 MB FPM sticks, 1024K, fastest timings, AMD X5-160. No HIMEM errors, Windows 98SE seems functional. I've tested a few graphics cards, USB cards, Intel NIC, PCI audio, ISA audio, and ISA ethernet cards without crashes. A max of three 64 MB FPM sticks work. The system doesn't turn on with four.
I removed the Funworld logo from the 4DPS BIOS and replaced it with the standard AWARD EPA logo. The important hack to the BIOS was the IRQ routing table. If you leave the standard 4DPS routing table in the BIOS and use it on the DTK board, the BIOS cannot seem to assign any IRQ to the PCI cards. The 4DPS BIOS was the closest match I could find to the DTK board - same chipset, same super I/O, no VLB. The only thing lacking is the 4DPS board has 3 PCI slots, whereas the DTK has 4. However, only 4 PCI masters are allowed. With the onboard IDE being 1 master, I think only 3 PCI slots are really usable. This particular 4DPS version fixes the 8 GB HDD size limitation, although I am still using an Ultra ATA PCI card on this system.
awdbedit was used to alter the IRQ routing table, but unfortunately I don't know all the INTA/B/C/D values used on the original DTK BIOS because the DTK BIOS won't open with awdbedit for whatever reason. I can open both BIOSes with MODBIN, but that only shows me the IRQ #'s used (see attachments). I am still stuck with the 4DPS INTA/B/C/D routing information. I need to somehow figure out how to interpret the HEX inside the DTK BIOS to find out what the INT's are and then put those into the 4DPS BIOS.
For now, the 4DPS BIOS works on the DTK with just altering the IRQ 6,7,8 numbers using awdbedit. IRQ's 9, 10, 11 get assigned to the PCI cards and the cards work in Win98SE, but PCI steering in Win98SE claims there is an error in the IRQ routing table - the consequence of this is probably just that Windows cannot reassign IRQs and we are stuck with what the BIOS presents.
Does anybody know a way to view the IRQ routing table for the DTK BIOS? I need the INT A/B/C/D values.
I also cannot use PCI slot #4. I was hoping to use it for a USB card for use with a USB/PS2 mouse, but since the system cannot assign an IRQ, it can't be used. But in reality, even with the DTK original BIOS, I got a hang-up when trying to use the 4th PCI slot as well.
When running the PCI bus at 40 MHz and using an ISA sound card, I found that using 1/4 clock setting for the ISA bus fixes crashing issues. Using the 7.1x MHz keyboard speed for the ISA bus caused eventual crashes when playing an mp3 in loop.
Now onto the good stuff. The 4DPS BIOS has a working PS/2 port. So I socketed the keyboard controller on the DTK board, and also socketed the 7406 inverter. I then proceeded to hook-up a HOLTEK keyboard controller in the exact same manner as on the 4DPS board. Note that the original 7406 inverter shown on the top right had some slight rewiring to change the double-inverter (buffer) used with a single keyboard to an inverter when used with a mouse configuration. Basically, I've hooked everything up just as it appears on the Holtek-HT6542B spec sheet for PS/2 mouse support. This is how the 4DPS boads have it hooked up.
I used mouse.com/test.exe to test the PS/2 mouse, but the system will hang right when I try to move the mouse or hit a click. Keyboard works fine though. I'm not sure what I'm doing wrong. I tried this with both the 4DPS and DTK BIOSes. My next step will be to try different PS/2 mice and check the wiring for a 4th time.