shadmere wrote on 2020-08-13, 23:32:
So, question. If I hook one of these hard drives up to my computer with an adapter, is Windows 10 going to immediately do a bunch of nonsense to that drive? Cause that seems good to avoid if I can.
I don't think Windows 10 will do anything to the drives. The few times I've done it in Windows, I haven't had any issues. You really just want to test the drives (surface scan, format, and copy some files around), so it shouldn't matter. Personally, I always partition and format drives in the target system. I have had problems when formatting on one computer and using on another, despite using the right settings.
shadmere wrote on 2020-08-13, 23:32:
Also have a third I/O adapter showing up tomorrow. Maybe that will help.
If that doesn't work I guess I'll get another motherboard? That sounds like giving up but agggh.
I know the feeling, but these old systems were finicky about everything. Throwing more parts at it will probably confuse things further. Don't give up.
Your best bet is to methodically divide and conquer, and take notes while you test. If you single mindedly attack a particular symptom, you'll eventually find the next puzzle piece.
These are the questions I would try to answer:
Is the original spinning disk OK?
If the disk tests OK on your modern PC, it could be a problem with the 486's hardware. >> Retest this good drive with the other controllers. If the problem continues on the other controllers, it's at the motherboard level. This could range from dirty contacts, bad power supply, all the way up to failing components on the motherboard.
If the disk tests BAD on your modern PC, then the CF card issues are probably unrelated.
Are the disk geometry problems caused by BIOS limitations/bugs?
Even if your BIOS should support a 4GB drive, it may have a bug that chokes on disk geometries that weren't available back in the day. XTIDE is a great tool to test this because it bypasses the motherboard BIOS and talks to the hardware directly.
I would configure and flash XTIDE for your system and retest the CF cards and the controllers. If this works, the problems were caused by the motherboard BIOS. There are not a ton of solutions to this apart from continuing to use XTIDE or finding a BIOS update. Practically speaking, losing 1k of conventional memory and a few kb of UMB has not caused me any actual trouble.
Are the disappearing partitions caused by CF card compatibility issues?
Not all CF cards are created equal. Some work well in CF to IDE adapters, others don't. I recently got a Pentium MMX industrial computer with an ATA-4 controller and a built-in CF card slot on the secondary IDE channel. You would think that's a best case scenario, but some cards work in it, others don't. I have also read of problems with writing the first sector (MBR and partition data) on some CF cards.
I get the sense that consumer CF cards can be hit or miss. There are CF cards made specifically for industrial computer applications, and I bet those would have a better chance of working in IDE mode.
Other folks may be more help with troubleshooting the CF cards. I have done very little with CF cards; I opted for SD cards instead because they're much more common.
As an aside: if you decide to shop for other storage mediums, check out Disk on Modules (DOM). These are SSDs that plug straight into the IDE socket. These are primarily used in industrial computers. Smaller sizes appropriate for a 486 are cheap and easy to find, and they're specifically designed to work with these older IDE controllers because industrial computers running 90's era hardware are not uncommon.