VOGONS

Search

Common searches

IBM PS/2 Model 25 on-board hard drive interface

Topic actions

First post, by Hamby

Posted on 
User metadata
Rank Member
Rank
Member

The only IBM system I've liked (other than the original 5150/5160/5170) was the PS/2 Model 25. I think they're cute, and I like the all-in-one design. I'd rather get a Compaq all-in-one, but they've been generally rarer to find and more expensive to get. Also I don't yet have an 8086/8088 system, and would like one for completeness.

I was looking into picking a model 25 up on ebay recently, and did a little light research.

From what I've found, it has an onboard, but proprietary hard drive controller.
Is the controller itself IDE compatible?
If so, and the only issues are the edge card connector on the drive cable, and power being provided via the cable, then couldn't one adapt a cable to work with a CF-IDE drive? The Startech adapters have an option for providing power through the cable.

The reason why I'd like to be able to do this is that I want to put a sound card, network adapter and hard drive in the system, and it only has 2 expansion slots. I suppose I could, if I had to, hang a sound card on the parallel port, or another alternative I thought of was an external zip drive (still booting off off floppy).

Anyway, does anyone know anything about the onboard controller for the model 25?

Reply 1 of 4, by Caluser2000

Posted on 
User metadata
Rank l33t
Rank
l33t

The hdd will be ST506 MFM type so the controller is not IDE compatible. http://www.primidi.com/ibm_personal_system2/t … chnology/models The same was the case with Acorn systems of the time. There were podules created for Acorns to use IDE drives though.

You can network over parallel port. https://www.brutman.com/Dos_Networking/xircom_pe3.html , fit a sound card and use a XT-IDE card of some type for sd, cf or hdd solution. Something like this https://monotech.fwscart.com/XT-CF_-_Bootable … 4_19915453.aspx or https://monotech.fwscart.com/XT-IDE_Bootable_ … 4_19478732.aspx I use the later on my XT Turbo setup and it works real well.

There's a glitch in the matrix.
A founding member of the 286 appreciation society.
Apparently 32-bit is dead and nobody likes P4s.
Of course, as always, I'm open to correction...😉

Reply 2 of 4, by luckybob

Posted on 
User metadata
Rank l33t
Rank
l33t

in addition to a 8-bit soundblaster, I have a 8-bit scsi card in mine. Solves the issues I had. Networking isnt that important, but I do have a parallel/ethernet adapter, should the need arise.

It is a mistake to think you can solve any major problems just with potatoes.

Reply 3 of 4, by eisapc

Posted on 
User metadata
Rank Member
Rank
Member

The 25 used the same disks like the 30 and probably 50, its ST506 but not the classic connector with 20 pin data and 34 pin control cable but a proprietary cardedge connector,
not to be mixed up with the ESDI DBA interface used in later models like Model 50z, 55 and 70.
Using an 8 bit ISA controller card with BIOS and an add on power cord would be the best way to attach an internal drive in such a system.
I am using a 8 bit SCSI board in my model 30 due to a dead original drive, offering a much larger capacity as a side effect.
Seagate ST02 or Future Domain TMC 850 are good choices if you can find one of these.

Reply 4 of 4, by luckybob

Posted on 
User metadata
Rank l33t
Rank
l33t

Not entirely true.

The 8088 25/30 are limited to the 20MB disks. The 30mb+ ones NEVER worked for any of my 7 total 8088 machines. That said, the larger drives did work in the 286 versions.

Stay away from these drives. They are TERRIBLE drives and if by some miracle the one you find isnt already failed, it will likely fail within a week of using it. Avoid at all costs.

I have desired to design and build a converter to use a CF card. But I lack the warewithall to do it.

It is a mistake to think you can solve any major problems just with potatoes.

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window