I believe I have my XT-IDE on D800h - D9FFh and my SCSI Controller at C800h - CBFFh.

I don't know if this will help you I have an adaptec scsi card but i cant remember which it is right now.

HanJammer wrote on 2020-06-11, 18:24:

3Com NIC is configured at 300h/IRQ10 with Boot ROM at C8000h-CBFFFh (still XT-IDE keeps informing me at boot it's @CA00h 😮).

I think it's configured for CA00h, and needs to be reconfigured/reprogrammed to work at another address.

Grzyb wrote on 2020-06-11, 21:11:

HanJammer wrote on 2020-06-11, 18:24:

3Com NIC is configured at 300h/IRQ10 with Boot ROM at C8000h-CBFFFh (still XT-IDE keeps informing me at boot it's @CA00h 😮).

I think it's configured for CA00h, and needs to be reconfigured/reprogrammed to work at another address.

But isn't the XT-IDE just loaded at the address set in the boot PROM configuration of the network controller?
I don't really see any options to change it in the xt-ide config utility...

I played with a Maxtech ISA NIC with a Future Domain bios installed, the card was not jumper set and used the software to configure the port, IRQ and boot rom address. IIRC had to also enable the boot rom or else would not see it during POST. Was many years ago but did finally get it to work and wished I had a jumper set NIC instead. Still have the card and the rom but have not played with it in years.

HanJammer wrote on 2020-06-12, 00:45:

But isn't the XT-IDE just loaded at the address set in the boot PROM configuration of the network controller?
I don't really see any options to change it in the xt-ide config utility...

Come to think of it, the reason may be that the 3Com expects a 16 KB ROM, but you're using an 8 KB one, so it appears at both C800 and CA00
Does the XTIDE Universal BIOS work correctly without the SCSI card installed?

If it does work alone, only can't coexist with the SCSI BIOS...
there was that "Late initialization" option, supposed to help in such cases - but it's only there in the old idecfg.com

Nope, I'm using 32kB ROM on the 3Com card. The contents are quadrupled, but yeah, thinking of it it reads the last portion first, so it may explain why it appears at CA00..
XT-IDE works just fine without SCSI card. I'm using this setup in many machines without problems, just for the first time with the SCSI card...
I'm not quite sure if I have this option in my xtide config, I will check later (also I will need to buy some of those 29C256 chips (supposedly a direct replacement for 27C256s) so I can reconfigure them without external programmer...

Also, try reversing the order of both BIOSes.
Higher address = initialized first, lower address = initialized later... or not at all, if the first BIOS has screwed up something.
XT Universal BIOS was designed to coexist with other adapter BIOSes, old SCSI controllers - not necessarily...

I encountered this problem at least 10 years ago, and I brought it up over on VCfed in the xt ide development thread. I think one or two other people there had encountered the same issue. I guess not enough people run XT IDE cards and SCSI together for the developers to do much about it. I was never able to get it to sit well with my SCSI controllers, even though there were no resource conflicts that I could find.

My solution was to use a SCSI IDE bridge instead.

BTW, what's currently the recommended XUB version?
Last time I checked, there was the stable version 1.1.5, and the neverending beta 2.0...

Anonymous Coward wrote on 2020-06-13, 05:40:

I encountered this problem at least 10 years ago, and I brought it up over on VCfed in the xt ide development thread. I think one or two other people there had encountered the same issue. I guess not enough people run XT IDE cards and SCSI together for the developers to do much about it. I was never able to get it to sit well with my SCSI controllers, even though there were no resource conflicts that I could find.

My solution was to use a SCSI IDE bridge instead.

One of the Acard based ones, I imagine ? There are some affordable LVDS ones available that should work on an old SE controller with passive adapters .

Indeed it was an Acard. If you decided to buy one, just be aware that some of them will only work with optical drives. I think the 7720U supports HDDs, but 7722 does not.

Anonymous Coward wrote on 2020-06-13, 12:41:

Indeed it was an Acard. If you decided to buy one, just be aware that some of them will only work with optical drives. I think the 7720U supports HDDs, but 7722 does not.

Thank you . That would explain why the affordable ones I see are 7722 based .

Grzyb wrote on 2020-06-13, 05:24:

Also, try reversing the order of both BIOSes.
Higher address = initialized first, lower address = initialized later... or not at all, if the first BIOS has screwed up something.
XT Universal BIOS was designed to coexist with other adapter BIOSes, old SCSI controllers - not necessarily...

I already tried that before I opened this thread, and it didn't work.