They way you describe it it looks like that particular 1GB CF card is quirky. I'd take the risk to try another one (different brand).

CF cards so probably same deal as sata-pata adapters Re: Motherboard refuses to see other IDE hard drive
tldr: CF card actually needs to explicitly support master/slave logic in IDE mode, not all did

Ah, I hadn't considered the CF card had something to do with M/S logic.
My 512MB card is an industrial type, while my 1GB card is a Transcend CF 133.

I've ordered an Industrial 1GB card, will update here when I get/test it.

Another option is to use an IDE connector on a sound card (ie: SB16, etc) for the cdrom with the "quirky" 1Gb CF.

Indeed, but there is an Orpheus 2 in there, and that sucka ain't coming out for nothin' 😉

1GB industrial card arrived, and unfortunately it behaves like the other >512MB cards I've tried. I.e. fine until I turn on the optical drive, then freezes after memory count.

I'm out of ideas, short of trying other CF IDE adapters, but at this point I don't want to throw any more money at this.

I borrowed a couple of CF IDE adapters from a friend.

No luck with running an optical drive using these, either. Same issue.
I can even run that dual card adapter with a 512MB & a 1GB card, in master/slave without a problem.
This must be some weird issue with the Ide controller on the motherboard and optical drives.

IDE is just a name for few IO port addresses accessed over ISA bus. Actual IDE controllers are on the HDD/CD drives.

>Using a 512MB card and an optical drive, the PC boots OK.

Your 1GB cards have insufficient compatibility. To be fair no CF card manufacturer probably ever cared about supporting CD drives on same IDE channel.

Even that industrial one? Specs say it does true ide. I've tried 6 cards total, and only that one Cactus 512mb works with an optical drive. I'm not spending anymore money experimenting on CF cards, I've already dropped nearly $100 on the damn things.

should have started with SSD and SATA-pata converter

Just curious, does it boot properly if you move the IDE cable + 1GB card + optical drive to another PC?

sangokushi wrote on 2023-07-13, 21:32:

Just curious, does it boot properly if you move the IDE cable + 1GB card + optical drive to another PC?

It's a good idea, and I had thought to try just that, I'll report back when I've done it.

rasz_pl wrote on 2023-07-13, 20:14:

should have started with SSD and SATA-pata converter

Perhaps, but the bios forces a max size of under 2GB, so I was looking for storage options that would be small enough. I've not seen any SSDs that small, though I suppose you could burn a bunch of the space by resizing the disk. Also, I wanted it to be easily removable for transferring files.

If you can, try using XTIDE - solves loads of these weird conflicts in my experience especially when they are around card identification/device conflicts

RockstarRunner wrote on 2023-07-13, 19:23:

Even that industrial one? Specs say it does true ide. I've tried 6 cards total, and only that one Cactus 512mb works with an optical drive. I'm not spending anymore money experimenting on CF cards, I've already dropped nearly $100 on the damn things.

"True IDE" is one of three modes that CF cards support.
The other two are "PC Card I/O Mode" and "Memory-Mapped I/O".

http://www.interfacebus.com/CompactFlash_Memo … ule_pinout.html

If you're using an USB card reader, some of those non-IDE modes might be used, perhaps.

Edit: If this was a gaming PC, I'd simply use the IDE/ATAPI port of a sound card.
They're being made for CD-ROM drives, after all.

I only have one ISA slot, which I already mentioned, and it's got an Orpheus 2 in it, so no room for xt-ide, and no ide header on the card... Yes, I really wish these awesome modern sound cards had that feature too, but I totally get why it's not worth the effort.

RockstarRunner wrote on 2023-07-15, 06:48:

I only have one ISA slot, which I already mentioned, and it's got an Orpheus 2 in it, so no room for xt-ide, and no ide header on the card... Yes, I really wish these awesome modern sound cards had that feature too, but I totally get why it's not worth the effort.

Crap -sorry, totally missed that sentence in your original post!
Think you *might* be able to add option roms direc tly to a system rom (eg https://www.plop.at/en/bootmanager/rom.html) but I have to say, I've never tried it.

No worries, and thanks for the link, I'll read up on that.

Just to conclude this issue I had, rasz_pl was exactly correct when he stated it was that the CF cards I had tested were not correctly supporting Matser/Slave functionality.
I was able to get a 2GB Cactus industrial CF card, and that , like the Cactus brand 512MB card worked perfectly when chaining a slave optical drive off of it.
During my testing I also tried a SATA/Pata adapter, but that turned out to be bad, something wring with the chip I guess, it got real hot, and the PC never recognized there was a drive attached.
I also tried a standard 3.5" HDD and that worked fine, but was never going to be an option for fitting in the case, mostly this indicated I should still see what CF cards I could get access to to test.
In summary, out of 7 CF cards I tried (including Transcend Industrial type), only the Cactus brand industrial cards worked. Now I won't take CF compatibility for granted in the future.

Thanks for all the advice given.