Those look like chipset registers, I wouldn't touch that.

What about first finding out what's your memory map?
Run checkit or msd and see what comes up. Then you'll find out what segments are free.

I'd configure the NIC on a different computer first, make sure it works properly.

zonared wrote on 2024-09-07, 11:27:

Do you think this will ever work on this old motherboard?

Yes!

Indeed, checkit. I had this once, with a 286 and 1MB that used the default ram Window for its bult in Ems functions where I set up the xt ide. Had to reconfigure the xt ide to a less usual ram window. Then it worked fine!

Also that pc had an option to allocate the ram above 640kB either to 640-1024 or above 1024, where the first range would remain problematic with the xt ide.

Thank-you both for replying to my post.

Firstly I am using an AT28C64B eeprom in the 28pin option rom socket. So I discovered (embarrassingly) that the WE (write enable) pin27, lines up with A14 (maybe A14, I'm not exactly sure what type of eprom is meant to go in these option rom sockets). Basically every time the system communicated to this eeprom, it corrupted the memory. So I double socketed my eeprom and bent pin27 out and soldered to pin28.

Ok, so with the eeprom in read only mode, I was able to see the contents of the rom via Checkit3:

But the 386 still wont boot from it...

In the BIOS is talks about setting RAM/ROM configurations. This doco talks about the 82C302 chip that controls these settings:
http://bitsavers.informatik.uni-stuttgart.de/ … _306_Prelim.pdf
If you look at pages 49 to 51 it seems to indicate that you need to set bit3 of 09H register to 1 to enable it. After reboot I no longer get any video. I can here the system running but things sound different, like pressing ESC to bypass ram test it sounds labored but things boot and the HDD seems to try and load MSDOS.

Nothing I do boots XTIDE. I tried it in my 486DX66 (https://theretroweb.com/motherboards/s/u-board-jk-042e#docs) and it doesn't work in there either 🙁

Thoughts? thanks again too.

Get the memory map using checkit, but don't load anything else, only himem.sys, and no rom cards.

That way you can see what segments are free. Only later, you are going to configure XTIDE to use those segments.

@tauro, thanks for your suggestion. After doing that, it shows addresses C800h to F000h is available. I have already set the NIC configuration for the option rom at address C800 (16kB). I was able to determine this earlier when I booted the system and pressed F5 to bypass normal bootup. so everything looks set correctly but it still doesn't work.

Is it related to the 82C302 settings? Doco seems to indicate you need to reserve space (assign either ram or rom to specific memory areas), but this doesn't seem to work on this board.

Any other suggestions?

zonared wrote on 2024-09-14, 12:29:

shows addresses C800h to F000h is available.

That's good news. Progress!

zonared wrote on 2024-09-14, 12:29:

Is it related to the 82C302 settings? Doco seems to indicate you need to reserve space (assign either ram or rom to specific memory areas), but this doesn't seem to work on this board.

I think it's related to you not having a working XTIDE card. You already mentioned that it didn't work on a different computer either:

zonared wrote on 2024-09-12, 11:38:

Nothing I do boots XTIDE. I tried it in my 486DX66 (https://theretroweb.com/motherboards/s/u-board-jk-042e#docs) and it doesn't work in there either 🙁

So as long as you don't get it to work on a different computer, I wouldn't put the blame on this particular one. I would concentrate on getting a ROM that works, and an appropriate ISA card, learning how to configure it properly, etc. Study this: https://www.xtideuniversalbios.org/

Thanks @tauro, I needed to re-read the doco at xtideuniversalbios.org. It now works.

What helped find the issue was installing the NIC with option rom in my old 286, when it booted it said the checksum failed for rom at c800h.

Straight away, I realised my checksum didn't exist, it was zeros. I knew this because the tutorial I had followed (not xtide, I cant remember which site) said when you import or load the BIN file into your eeprom programmer, you select 'Clear buffer with 0x00", which is WRONG!!!

Following the xtide doco, it says open xtidecfg.com, load BIN file (mod if you want), then save it, this creates the checksum (apparently very important, who would have thought), then select "Clear buffer with default" when you load into eeprom programmer. Now it works, xtide running perfectly on my old 386. yay.

What is annoying is the fact that neither the 386 nor the 486 gave an error message indicating the rom failed it's checksum. It took an even older 286 to before I received a message saying something was wrong. Wow, talk about a backward step on diagnostic feedback 😀

I want to say thanks to everyone for helping, much appreciated. Now to reformat my 6.4GB HDD to allow fdisk to see more than 528MB

Quick one, the title of this post asks the question about allowing space for option rom. The reason I was receiving the message saying "Cant allow space for rom (between C0000 - DFFFF)" from the set8009r.exe program was because I was running this program after ALL the MSDOS drivers and TSR had loaded and consumed all the RAM locations. If you press F5 to bypass normal MSDOS start, you'll have heaps of space and chances are there will be space between C0000 and DFFFF to assign the rom to. My other issues muddied the waters some what. I guess you don't know what you don't know.

I've never played with this type of thing (ROMs), so its been interesting and fun to find out all this type of stuff was supported by these machines natively way back then. Thanks again... 👍

You're welcome my friend, glad you had it sorted out! Sometimes it's painful to learn new things but it's worth it 😎