Linoleum wrote on 2024-12-24, 04:32:

Keep ideas coming and I’ll report back in few days (after Xmas).

Merry Christmas ! If I can think of anything else to try that is easy (not likely 😀 ) will post it.

Linoleum wrote on 2024-12-24, 03:04:

Why are MSDOS 6 and Win95 killing my primary slave port!?!

I told u - its a glitchy/uncommon/cheap realization of IDE(ATAPI) protocol in your chipset or BIOS but u sure everything are OK... 😉

Babasha wrote on 2024-12-24, 06:43:

Linoleum wrote on 2024-12-24, 03:04:

Why are MSDOS 6 and Win95 killing my primary slave port!?!

I told u - its a glitchy/uncommon/cheap realization of IDE(ATAPI) protocol in your chipset or BIOS but u sure everything are OK... 😉

Yeah… now that I ruled out mscdex, himem, emm386 and the drivers themselves it’s possible…

Food for thought: would it have to do with IO.sys? Each OS has its own version of IO.sys and that its job to manage peripherals...

What computer are you actually using? Is it a compaq? which one, please give all specs.

weedeewee wrote on 2024-12-24, 14:18:

What computer are you actually using? Is it a compaq? which one, please give all specs.

Like I said in the intro, it’s a Compaq Prolinea 2/50. The pizza box kind of Compaq… I understand the rest of the info is spread in the multiple replies, so I’ll sum it up here:

IDE 0: ide to cf adapter 4GB cards (no other ide channel) + Mitsumi FX600S
FDC: 1.44mb
ISA: SB16 CT2940
CPU: dx2 50

Linoleum wrote on 2024-12-24, 15:39:

Like I said in the intro, it’s a Compaq Prolinea 2/50. The pizza box kind of Compaq… I understand the rest of the info is spread […]
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weedeewee wrote on 2024-12-24, 14:18:

What computer are you actually using? Is it a compaq? which one, please give all specs.

Like I said in the intro, it’s a Compaq Prolinea 2/50. The pizza box kind of Compaq… I understand the rest of the info is spread in the multiple replies, so I’ll sum it up here:

IDE 0: ide to cf adapter 4GB cards (no other ide channel) + Mitsumi FX600S
FDC: 1.44mb
ISA: SB16 CT2940
CPU: dx2 50

Thanks. Oh in your first post you mention a 4/50, though i see in your other post you mention a 2/50. anyway.
So with the compaq dos it's working, but with the standard microsoft dos it isn't.
Interesting. It somehow feels familiar.

I might be misremembering, but have you checked if you can get the cdrom working in windows when you do not load any cdrom drivers in dos. long shot I know.

weedeewee wrote on 2024-12-24, 16:13:

Thanks. Oh in your first post you mention a 4/50, though i see in your other post you mention a 2/50. anyway. So with the compaq […]
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Linoleum wrote on 2024-12-24, 15:39:

Like I said in the intro, it’s a Compaq Prolinea 2/50. The pizza box kind of Compaq… I understand the rest of the info is spread […]
Show full quote

weedeewee wrote on 2024-12-24, 14:18:

What computer are you actually using? Is it a compaq? which one, please give all specs.

Like I said in the intro, it’s a Compaq Prolinea 2/50. The pizza box kind of Compaq… I understand the rest of the info is spread in the multiple replies, so I’ll sum it up here:

IDE 0: ide to cf adapter 4GB cards (no other ide channel) + Mitsumi FX600S
FDC: 1.44mb
ISA: SB16 CT2940
CPU: dx2 50

Thanks. Oh in your first post you mention a 4/50, though i see in your other post you mention a 2/50. anyway.
So with the compaq dos it's working, but with the standard microsoft dos it isn't.
Interesting. It somehow feels familiar.

I might be misremembering, but have you checked if you can get the cdrom working in windows when you do not load any cdrom drivers in dos. long shot I know.

My bad! It’s indeed a 4/50…

Yeah! I gave that a shot and didn’t work… Don’t quote me on this, but it might be a Win98 feature.

I found the source of the problem!!! I still don't understand why, though. It turns out it's one of the CF cards!

After finding some time to play with the MS-DOS 5.0 and MS-DOS 6.0 floppy boot disks, I found that they both worked correctly and loaded the MTMCDAI driver flawlessly. So, it's not an OS problem.

I realize I had my first 4GB CF with Compaq DOS 5.0 as the master disk... When swapping in for my other 4GB CF that I used to set up MS-DOS 6.0 and/or Win95, the driver would not load! They are both 4GB and physically identical (same generic blue stickers)... BUT, one has slightly more space (aka sectors) than the other.

I made 10000% sure the "faulty" one was empty by deleting all partitions and even tried "size adjustment" option of SdFormater... Couldn't load MTMCDAI. I Tried cloning the "good one" onto the "not so good one", still couldn't load MTMCDAI!!
I can't believe that just a slight difference is size totally breaks ATAPI/IDE of the slave drive.

Good you found your problem.
There's plenty of threads that talk about incompatibilities with regards to the use of CF cards on the IDE bus.
Now there's one more.

Might I suggest you edit the title of this post and add [solved] to it.

Have fun.

Linoleum wrote on 2024-12-24, 19:40:

I found the source of the problem!!! I still don't understand why, though. It turns out it's one of the CF cards! […]
Show full quote

I found the source of the problem!!! I still don't understand why, though. It turns out it's one of the CF cards!

After finding some time to play with the MS-DOS 5.0 and MS-DOS 6.0 floppy boot disks, I found that they both worked correctly and loaded the MTMCDAI driver flawlessly. So, it's not an OS problem.

I realize I had my first 4GB CF with Compaq DOS 5.0 as the master disk... When swapping in for my other 4GB CF that I used to set up MS-DOS 6.0 and/or Win95, the driver would not load! They are both 4GB and physically identical (same generic blue stickers)... BUT, one has slightly more space (aka sectors) than the other.

I made 10000% sure the "faulty" one was empty by deleting all partitions and even tried "size adjustment" option of SdFormater... Couldn't load MTMCDAI. I Tried cloning the "good one" onto the "not so good one", still couldn't load MTMCDAI!!
I can't believe that just a slight difference is size totally breaks ATAPI/IDE of the slave drive.

Nice! I never use drives large of 528mb on 386/early 486 systems so no such experience (its better to say long ago i get really bad experience and dont try it now). 😀

Linoleum wrote on 2024-12-24, 19:40:

I can't believe that just a slight difference is size totally breaks ATAPI/IDE of the slave drive.

Its not just difference in total size, size difference suggests different guts = different firmware and defaults. CFs werent really tested for Master/Slave compatibility all that thoroughly.

rasz_pl wrote on 2024-12-25, 06:21:

Linoleum wrote on 2024-12-24, 19:40:

I can't believe that just a slight difference is size totally breaks ATAPI/IDE of the slave drive.

Its not just difference in total size, size difference suggests different guts = different firmware and defaults. CFs werent really tested for Master/Slave compatibility all that thoroughly.

Makes sense. I tested another 2gb card and this one didn’t work as well… So not size related indeed.

I ordered a few 4GB from different brands to see if there is a pattern…