IBM PS/2 Model 25 with XTIDE Universal BIOS

[pearce_jj]

I'm troubleshooting an issue with an IBM PS/2 model 25 (8086 based) using Revision 0 system ROM (the ROM contains at the start 00F2122 (C) COPYRIGHT IBM CORPORATION 1981,1987 ALL RIGHTS RESERVED) with XTIDE Universal BIOS (XUB).

I can see previous threads where people get this machine working with the XUB but it doesn't want to initialise it at boot.

A known working card (in this case, XT-CF lite v2) can be programmed in the system OK and the XUB code can be read back from the card (after reboot) at the expected memory location. But, the XUB is not initialised at boot. Both standard and late initialisation have been tried.

It should be noted that the model 30 (286 based?) cannot be used with this card due to the hard-wired ZWS driver (ISA B8). However, I would presume that B8 is unconnected in the 8086 based Model 25?

 

[dhau]

I have a 8086 model 30, and I have the same issue. A known working XT-IDE card doesn't have it's BIOS pop-up. I was thinking of fiddling with segment and port may be. Haven't got to it yet.

 

[pearce_jj]

Thanks. At least with the ROM at D800, I think it's OK - the ROM can be seen in the memory address space just fine. Do you have the system configuration disk? I wondered if that might have any settings relating to option ROMs. I did read mention of two ROMs in these machines (one for OS/2) but I presume, being 8086, these machines will have only a single ROM.