For the life of me, I can't seem to find any BIOS chips for sale anywhere that might let me test this new theory. I don't know how to verify that a system can be run from option ROMs, so I'm not sure how to go about moving forward.

I'm also trying to keep things very budget-friendly at this point so shelling out cash in great amounts isn't going to happen.

elvovirto wrote on 2023-02-20, 22:47:

For the life of me, I can't seem to find any BIOS chips for sale anywhere that might let me test this new theory. I don't know how to verify that a system can be run from option ROMs, so I'm not sure how to go about moving forward.

I'm also trying to keep things very budget-friendly at this point so shelling out cash in great amounts isn't going to happen.

Why not try OnTrack or EZDrive?

jakethompson1 wrote on 2023-02-20, 22:56:

Why not try OnTrack or EZDrive?

I have actually tried OnTrack - no matter what card is installed, it bombs out with an "Unrecoverable IO Error"

It should be noted I haven't tried EZDrive because the info I found at Philscomputerlab stated it needed 4Mb of RAM.

EDIT: Tried EZDrive for the sake of trying - first attempt crashed with stack overflow, second attempt said the drive was already setup and then hard locked.

I had this 386 SCAT Mobo: https://theretroweb.com/motherboards/s/jc-inf … -ii-model-2050b

Generally, it booted fine with IDE storage devices < 528MB but crashed during or shortly after boot when IDE storage devices larger than 528MB were attached to system.

This would happen regardless of whether I used the original C&T Bios or the after market MR Bios 1.65 "V032B300", whether I had XTIDE UBE installed or whether I used a storage device with EZ drive or not.

I eventually discovered that if I used an IDE controller that had SIIG Enhanced IDE option rom v1.05 installed, the computer wouldn't crash when an IDE storage device > 528MB was attached. It still couldn't boot from storage > 528MB but it was stable. The SIIG ROM is here: http://vogonsdrivers.com/getfile.php?fileid=1816&menustate=0

At that point, I attached an IDE storage device > 528MB that had EZ drive installed and it and the system booted and was stable.

So the solution was to combine the SIIG Enhance BIOS option rom with EZ drive, or stick with IDE storage devices < 528MB . Those were the only two working combos I found.

I tried a lot of drive geometries in the BIOS to see if I could find a magic number that was causing the problem or find a stable configuration. Sometimes I could get a drive to work if it was configured between 528MB and 1GB, but I can't remember what those values were. Usually it turned out that the different geometries just caused things to be less "unstable". When it would crash, it would look like something was overwriting RAM, so a bad pointer or missing address line? Edit: Or non standard DMA controller?

Strange, no?

I do remember these enhancers! They really do work, at least for Award/Ami BIOSes. Haven't tested them with others yet.
Some also shipped with those Year 2000 upgrade cards.

Jo22 wrote on 2023-02-21, 14:45:

I do remember these enhancers! They really do work, at least for Award/Ami BIOSes. Haven't tested them with others yet.
Some also shipped with those Year 2000 upgrade cards.

After looking a bit at the end of that linked thread, I figured I'd check for an E-IDE card on eBay. There are only two ISA options currently listed - and one of them is over 100 bucks.

When I think of all the stuff I tossed or donated over the years it's like...man...I wish I still had (Insert Hardware I used to have here).

douglar wrote on 2023-02-21, 14:26:

I had this 386 SCAT Mobo: https://theretroweb.com/motherboards/s/jc-inf … -ii-model-2050b

That definitely looks like CHIPs evolution of cost-reducing the hardware. My board has probably 4 or 5 quad flat packs labeled CHIPs, a huge array of sockets for DRAM and 4 SIPP sockets. There are at least 3 AMI labeled ROMs (keyboard, even BIOS, odd BIOS) and 4 16-bit and 2 8-bit ISA slots. It makes sense - this board is at least 2 years newer, possibly more.

It's a shame this has been such a mind-wracking project. I mean, a 386SX is nobody's idea of a dream PC, and even though my first "modern" PC was also a 16Mhz 386SX, I don't feel particular love for it. I simply want to save it from being discarded and ground into dust.

elvovirto wrote on 2023-02-21, 15:44:

After looking a bit at the end of that linked thread, I figured I'd check for an E-IDE card on eBay. There are only two ISA options currently listed - and one of them is over 100 bucks.

When I think of all the stuff I tossed or donated over the years it's like...man...I wish I still had (Insert Hardware I used to have here).

There is a (slim but > 0%) chance that the SIIG option rom might work without the SIIG ide card installed. If you got the hardware, you could try putting it on an network card.

But it does seem like there is a better chance that it is something about that IDE controller chip that fixes the issue and not the ROM.

Or try a small (<512MB) storage device

douglar wrote on 2023-02-21, 16:07:

There is a (slim but > 0%) chance that the SIIG option rom might work without the SIIG ide card installed. If you got the ha […]
Show full quote

elvovirto wrote on 2023-02-21, 15:44:

After looking a bit at the end of that linked thread, I figured I'd check for an E-IDE card on eBay. There are only two ISA options currently listed - and one of them is over 100 bucks.

When I think of all the stuff I tossed or donated over the years it's like...man...I wish I still had (Insert Hardware I used to have here).

There is a (slim but > 0%) chance that the SIIG option rom might work without the SIIG ide card installed. If you got the hardware, you could try putting it on an network card.

But it does seem like there is a better chance that it is something about that IDE controller chip that fixes the issue and not the ROM.

Or try a small (<512MB) storage device

I've been trying 32MEGAbyte SD cards. The next smallest I have is 2Gb. I'm sure I also have a 64 and 128Mb card somewhere but the question is "where?"

elvovirto wrote on 2023-02-21, 16:12:

I've been trying 32MEGAbyte SD cards. The next smallest I have is 2Gb. I'm sure I also have a 64 and 128Mb card somewhere but the question is "where?"

OK. 32MB SD cards should be small enough, yes.

douglar wrote on 2023-02-21, 16:32:

elvovirto wrote on 2023-02-21, 16:12:

I've been trying 32MEGAbyte SD cards. The next smallest I have is 2Gb. I'm sure I also have a 64 and 128Mb card somewhere but the question is "where?"

OK. 32MB SD cards should be small enough, yes.

I would think so. I suppose there could be a random issue with them, maybe they're too slow? They're obviously old to be that small. But I'm willing to bet they're still too fast for the controller or BIOS.

I guess the question is starting to become one of cost/value. I could try another controller card, but current ebay stock is limited and prices are high. I could purchase an XTIDE card but that's only 8-bit and similar to another controller card.

I could buy a eeprom programmer and attempt to find a newer odd/even BIOS for this motherboard. I could potentially buy a NIC and see if I can boot an option ROM but that would also require a programmer.

I suppose the other possibility is give up on this mainboard and swap it for another baby AT style board, 386DX or 486, possibly. This is probably the best return on investment, but also the most costly since the only good source I know for mainboards would be ebay.

Not sure. I've never programmed eeproms before. It could be fun or it could be a pointless rabbit hole. I see programmers ranging from 8 bucks to 100 easily and have no idea where to start.

You mentioned that things worked at 8Mhz and not at 16Mhz. Seems probably that the ISA bus speed might be tied to the CPU speed, like maybe your buss speed runs slower at 4Mhz.

If that's the case, then maybe your Motherboard isn't able to run at the higher frequency anymore with multiple devices attached.

douglar wrote on 2023-02-21, 19:13:

You mentioned that things worked at 8Mhz and not at 16Mhz. Seems probably that the ISA bus speed might be tied to the CPU speed, like maybe your buss speed runs slower at 4Mhz.

If that's the case, then maybe your Motherboard isn't able to run at the higher frequency anymore with multiple devices attached.

Ah, that was using a CF adapter. I actually have two. One that I know works in my P120 that causes the 386 to black screen and never post. The one that DOES post corrupts the screen at 16Mhz but not at 8. I haven't even tried to use it to install DOS as I'm not willing to run that slowly on such a glacial system. I switched to one of the common generic SD to IDE adapters and haven't had any issues posting or with graphical errors.

OK - so for sake of trying everything I can, I pulled the SD adapter and plugged the CF adapter that causes graphical issues back in. The CF card installed is 2Gb and already has working ontrack/dos install. It boots normally at 8Mhz. At 16Mhz, it seems to boot but you can't tell what's going on beyond garbage rolling up the screen as it loads.

You can run chkdsk and it'll complete fine, but it takes probably 2 minutes to do so.

So CF WORKS but is effectively unusable at 16Mhz. SD "works" in that you can see and write to disk but once you read it's game over.

The only device on the IDE channel is whichever one adapter I have connected at a time. There are also 2 floppy drives.

Is there any option in the BIOS that allows you to set the ISA bus frequency multiplier (it may also be labeled as "AT Bus Clock" or something similar)? I suspect that when you run at full speed the ISA bus may be using the incorrect multiplier, resulting in a speed that is too much to handle for the controller (and maybe also the graphics card).

This was the closest thing I could find in the CMOS setup to clocking.

I tried changing it to all the available values (other than reserved) and the system will have graphical errors with or without the CF reader installed and at either 8 or 16Mhz.

elvovirto wrote on 2023-02-21, 20:22:

This was the closest thing I could find in the CMOS setup to clocking.

I tried changing it to all the available values (other than reserved) and the system will have graphical errors with or without the CF reader installed and at either 8 or 16Mhz.

Hi

This is too early motherboard, this was exactly like that, what I had back in the day, all white text CMOS settings, C&T (CHIPS) and 386DX 25. No matter what I tweak the settings to speed up, board crashes so I left it to defaults plus C&T chipset is very slow chipset, and not made for speed.

Stick to using 512MB or less CF and set the hard drive type to 504MB, then fdisk and delete all partitions, recreate the partitions and finish the rest.

Cheers,

pentiumspeed wrote on 2023-02-21, 20:28:

Hi […]
Show full quote

elvovirto wrote on 2023-02-21, 20:22:

This was the closest thing I could find in the CMOS setup to clocking.

I tried changing it to all the available values (other than reserved) and the system will have graphical errors with or without the CF reader installed and at either 8 or 16Mhz.

Hi

This is too early motherboard, this was exactly like that, what I had back in the day, all white text CMOS settings, C&T (CHIPS) and 386DX 25. No matter what I tweak the settings to speed up, board crashes so I left it to defaults plus C&T chipset is very slow chipset, and not made for speed.

Stick to using 512MB or less CF and set the hard drive type to 504MB, then fdisk and delete all partitions, recreate the partitions and finish the rest.

Cheers,

Card size is not my concern. It currently has a 2Gb CF card in the reader from another system that was already configured with OnTrack. DOS sees all 2Gb regardless of what the CMOS settings are.

Here are my actual issues:

If you use this CF reader, you are UNABLE to run the system at 16Mhz. It works fine at 8Mhz - otherwise the display is garbled.

If you use my spare CF reader, which lives full-time in my P120, the system won't even POST.

If you use the SD adapter I bought specifically to try on this system, there are no display issues at 8 or 16Mhz. You can FDISK/Format/etc but once you try to read from the device, it craps itself. DOS 6.21 cannot complete an install, and if you SYS the device, it cannot boot from it. If you attempt to use OnTrack, it fails with an unrecoverable IO error. EzDrive stack overflows. This occurs regardless of the brand or size of card installed.

I have ordered one additional type of CF adapter that will connect directly to the IDE header pins on the controller card without using a cable.

This depends on CF cards are used. What are these?

I had to carefully choose good CF cards. Ones that works well were industrial grade. I'll test on very old computer I can do is rabbit chipset 386 that I have now. None of boards I have have C&T chipset as I had terrible experience with them in past working on them that were not mine including one I had back in the day and sick 286 boards with C&T too.

Cheers,

Seems unlikely that swapping CF adapters is going to make a difference in this case. They just plug the 40 pin IDE through to the CF, no chips or intelligence in the device. Seems like your issue is placing an IDE device at the higher clock speed it the issue, regardless if it is an SD bridge or a CF adapter, since things do work at the slower speed.