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IBM p70 questions....

tblake05

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If it is a SCSI drive then you have a lot of options, including ones for replacing it.

That's really supposed to be an ESDI drive. The model number doesn't generate a lot of hits on Google, so the specs won't be found by casual online searching. Can you remove it temporarily and show us the connector and circuit board?

Here are a couple pictures of the connector.

93D88406-4AA4-43E0-AB83-2A3E24F27F39.jpegE92A6DFF-6958-473C-BB00-C88F2ADE71C2.jpeg
 

RussBlakeman

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Apparently it is ESDI - you might find this P70 Project page of some help: https://jshorney.incolor.com/p70.htm especially in the first section marked information where it states three different submodels, all with ESDI drives. I have no idea where I got that it was SCSI other than the fact it's been too long since I've messed regularly with any PS2 machine. Jim Shorney that owns that site is one of the PS2 knowledgeable people that I remember from the old PS2 newsgroup. BTW the setup disk image (or a link to it) should be on his site as well
 

Eudimorphodon

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Apparently it is ESDI - you might find this P70 Project page of some help: https://jshorney.incolor.com/p70.htm especially in the first section marked information where it states three different submodels, all with ESDI drives.

Per the previous post from njroadfan it might be nice if people started referring to these as "DBA" drives, or something, not "EDSI". As the link above states under the "Hard Disk" section these drives are really more like a MicroChannel version of IDE than a "real" EDSI disk with a separate controller. IBM referred to them as ESDI in some of their documentation mainly to denote that they used controllers that "translated" disk geometry like was standard on ESDI drive+controller combinations at this point in time. By the same token you could just as legitimately call most (nearly all) IDE drives "ESDI".

I think a few of the early tower format PS/2s (Models 60/80) used "real" ESDI hard drives, but that's about it.
 

Caluser2000

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RTFM is always a good idea to find out more about the system you are working on.

If Big Blue refers to them as ESDI hdds it's good enough for me...
 

mbbrutman

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I'll make amends for suggesting that it might be an ESDI drive.

My secret stash of IBM documentation calls the interface "Direct Bus Attach", so it is neither ESDI, SCSI or IDE. It directly attaches tot he system on the MCA bus, but presents itself as an ESDI drive logically. They were used in the model 50Z, 55, and 70.

For the purposes of this thread it really doesn't matter what it is, as it's still an oddball that can't be moved to another system to be imaged.
 

Eudimorphodon

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I'll make amends for suggesting that it might be an ESDI drive.

My secret stash of IBM documentation calls the interface "Direct Bus Attach", so it is neither ESDI, SCSI or IDE. It directly attaches tot he system on the MCA bus, but presents itself as an ESDI drive logically. They were used in the model 50Z, 55, and 70.

For the purposes of this thread it really doesn't matter what it is, as it's still an oddball that can't be moved to another system to be imaged.

FWIW, if you look hard enough you can find instances where IBM used "ESDI" to describe the drives, like, this announcement letter for the PS/2 Model 70 has this one (presumably slightly garbled) sentence in it:

The 80386 processor models 081 (80 million bytes/20MHz), 161 (160 million bytes/20MHz), A81 (80 million bytes/25MHz) and A16 (160 million bytes/25MHz) enhance ESDI files and support the addition of an 80387 optional Math Co-Processor, which offers significantlyimproved system performance for a desktop environment.

(The announcement for the P70 does not have the word in it.) There is also this maintenance manual (published well after the machines were not on sale anymore but still being supported in the field) that refers to the drives as "ESDI":

1 30MB Hard Disk Drive (ESDI) 6128287
(Includes ESDI hard disk controller)
1 60MB Hard Disk Drive (ESDI) 6128294
(Includes ESDI hard disk controller)
1 120MB Hard Disk Drive (ESDI) 6128291
(Includes ESDI hard disk controller)

But notably the parentheses indicate that the drives have integrated ESDI controllers, IE, they're not "normal" ESDI drives. Also, this is not a technical reference manual, it's a service manual for parts-swapper drones that just need "a name" for the part they're looking for. Outside of these sort of very rare references there is very limited evidence that IBM referred to these drives as being anything other than "fixed disks" or "DASDs", the interface/technology was not something they really advertised and none of the actual technical manuals including this very complete "DASD Storage Interface Specification" reference describes anything about the interface or the API as "ESDI".

Long and short of it is, yeah, they "look like" ESDI drives logically but the interface is nothing like a normal ESDI drive, so it seems kind of wrong to call them that; specifically for the purposes of this thread if you call them ESDI it might raise false hopes that someone could somehow hook these drives up to a ESDI controller in a generic machine or connect a generic ESDI drive to their PS/2 with some kind of adapter cable. But on the flip side, if you're searching specifically for a PS/2 drive there's a non-zero chance it'll be described as ESDI instead of or in addition to "DBA" or whatever, so, eh, there's no way to win.

Ultimately I guess it doesn't matter what you call them in discussions as long as it makes clear that they're proprietary and therefore you're pretty screwed. Ultimately the whole point of this interface was to make it difficult for PS/2 customers to buy drives from anybody but IBM so it's not surprising there was never an official popular name for it.
 
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mbbrutman

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Which is why I asked to see the connector .. that answers a lot of questions.

I have an ESDI controller and drive here somewhere. That card edge connector just reaffirms my assertion that the data recovery should be done in the original machine.

Gotta love the IBM PS/2 product planners. Putting a proprietary connector for an unpopular bus is kind of special. As much as I enjoy IBM year, I generally avoid the PS/2 line because of things like this.
 

tblake05

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Which is why I asked to see the connector .. that answers a lot of questions.

I have an ESDI controller and drive here somewhere. That card edge connector just reaffirms my assertion that the data recovery should be done in the original machine.

Gotta love the IBM PS/2 product planners. Putting a proprietary connector for an unpopular bus is kind of special. As much as I enjoy IBM year, I generally avoid the PS/2 line because of things like this.

Hopefully someone can walk me through that. Pretty much step by step, what cable I need, what software I need (hopefully dos software), and what commangs I need to run on the receiving machine. Because I am pretty much clueless when it comes to stuff like this. BUT I would really like to extract the data off this machine..
 

njroadfan

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The "easy" way is to just use INTERSVR and INTERLNK from MS-DOS 6.x. I've backed up a ton of data from these non-standard machines using that software and a "Laplink" wired parallel cable. The software supports serial cables as well. The actual LapLink software will work too, but INTERLNK was a free option and usually pre-installed in just about every machine I encountered.
 

tblake05

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Ooh boy. Networking and terminals is usually pretty over my head but I’ll read up on it and give it a shot. Thanks!
 

mbbrutman

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Do INTERSVR and INTERLNK do file level backups or sector level backups?

I suggested using custom code with a network adapter that does sector level backups, so that no hidden files are missed. You can also do forensic examination on the resulting image, including looking in the unallocated spaces for other data that was previously deleted.
 

Caluser2000

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