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Ps/2 25-8086 ide?

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linuxlove

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Been wondering what the J11 header is for and I looked it up on statson.org. They say it's an IDE interface.
Is this right? If it is, is it the XT-based IDE or something that IBM came up with?
 
Totally proprietary. There were two sizes of drives, a 20Mb and 30Mb. The 8086-based Model 30 could only run the 20Mb size (I believe it was a Type 26 on their own drive table), the Model 25, Model 25 286, and Model 30 286 could operate either.

There was also a specific I/O port register that could disable the planar resources, including the HDD interface (if the single drive wasn't plugged in, the controller was disabled automatically)...
 
The 386SX-based Model 25SX had a true IDE interface on the planar (there were other PS/2 models with that as well: 33, 35SX, 40SX, L40SX, and microchannel 53SLC2). One unit, the notebook microchannel N51SLC, had a rare IBM-made adapter that converted the DBA ESDI interface to IDE. There were a few third-party IDE adapters for microchannel (PS/2 models 50 and above), but the controller was typically on non-standard I/O ports.
 
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FWIW, with that interface being so brutally useless, what I did with my 30 was make a little cable that takes power from the power pins in that "IDE" connector (it is a single cable to the drive including power) and goes to a 4-pin 'Molex' drive connector. This way you don't need to hack up the PSU or only use interface cards that provide a power connector (as they are less common than the connectorless versions).
 
Man.... guess this means I'm going to either have to attempt to fix my existing drive that won't boot, or replace it with a working model.... or pop an XT-IDE in there.

Decisions, decisions. I was thinking that it had a standard IDE interface.
 
Not only is the "IDE" interface in my PS/2 Model 30-286 totally proprietary, it also uses a hard drive which is totally forgotten about: the Seagate ST-125L. I can find plenty of documentation on the plain ST-125 (a standard 3½" 20 MB MFM drive), but there is no information anywhere on this version with the "L" suffix. The best I can determine is that it is the same thing as the regular ST-125, except with the MFM controller integrated into the drive's onboard circuitry, thereby technically being "Integrated Drive Electronics" (IDE) but nowhere near compatible with any standard ATA (IDE-AT) drive.
 
vwestlife said:
Not only is the "IDE" interface in my PS/2 Model 30-286 totally proprietary, it also uses a hard drive which is totally forgotten about: the Seagate ST-125L. I can find plenty of documentation on the plain ST-125 (a standard 3½" 20 MB MFM drive), but there is no information anywhere on this version with the "L" suffix. The best I can determine is that it is the same thing as the regular ST-125, except with the MFM controller integrated into the drive's onboard circuitry, thereby technically being "Integrated Drive Electronics" (IDE) but nowhere near compatible with any standard ATA (IDE-AT) drive.
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I hate to bump an older thread, but you are absolutely correct. The ST125L was completely unrelated to the SCSI version, the ST125N and the non-scsi version which I believe was MFM like you mentioned. It used a very weird edge card connector to it's main board and was impossible to upgrade. Back in the day, we used an Seagate st01 SCSI controller without a BIOS to add a second hard drive on a 'hardcard' as it was known at the time. We were able to add a Quantum 240Mb drive. We also went on to upgrade the ram to the full 4MB, the processor to a 486slc and we even had two different coproessors and other cpu upgrades. We were able to run win 3.1 in enhanced mode, which was quite a feat. The system is still here sitting behind me. I hope it still works when I have time to turn it on again...
 
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