PS/2s nicer than expected; some questions

From: Bruce Lane <>
Date: Wed Mar 24 08:43:57 1999

At 23:39 23-03-1999 -0700, you wrote:

>I was impressed with the build quality and design of the machines (the
>power supply in the M95 XP486 for example: undo one butterfly screw and the
>whole thing swivels out, allowing easy access to the drive bays) and with

        Yeppers. I've got a Model 85 and a 95 here.

        If your M95 came with a Type 4 CPU complex, I'm really going to get
jealous! ;-)

>1) Why did Microchannel fail so completely? From a user point of view it
>seems quite nice.

        It was. Most folks, myself included, believe it failed because IBM wanted
to keep the patent on it and wouldn't license it for anything less than a
king's ransom to anyone else. On top of that, even after the license, they
wanted to extract royalties for every MCA-capable machine built.

        The only other maker that I know of that built MCA-slot machines was NCR
with some of their larger servers.

        In essence, IBM's own greed and arrogance killed MCA in the market. Had
they declared it 'open,' as ISA was, I firmly believe we'd all be MCA'ers
to this day.

>2) Can MFM or IDE drives be used with an ESDI controller, or do the drives
>have to be ESDI drives?

        No, they must be ESDI drives. The only thing ESDI has in common with
MFM/RLL is the cabling.

>3) Anybody know if the 486DX33 on the processor board can be replaced with
>an Overdrive chip to make it at least a 486/66; or, does IBM still run
>their parts depot in Boulder for old machines?

        You should be able to up it to at least a DX2-66. However, don't count on
an overdrive chip running in the thing. PS/2's are notoriously picky about
their hardware.

>but the system won't boot from the hard drive alone. If I boot with a
>floppy in the drive, I can access the HD and run programs off of it. But
>without a floppy, nothing works. Any ideas?

        I've seen behavior like that before. It usually means the hard drive is

        As it turns out, I have a spare hard drive for a P70/386 that's just
gathering dust here. Perhaps we can work a trade or a cheap sale? I promise
I won't gouge. ;-)

        Another option is to install a third-party SCSI adapter, such as an
Adaptec 1640 or Future Domain card, and stick a SCSI drive in there. Bear
in mind that you'll need to do some minor mechanical surgery to the drive
bracket since the holes are non-standard spacing.

        Can you tell I just went through all this? ;-) Yes, I have a nice P70
portable that has, thanks to installation of a 486 upgrade card and SCSI
adapter, been converted to be a portable testbed for SCSI devices.

Bruce Lane, Owner and head honcho, Blue Feather Technologies
Amateur Radio:(WD6EOS) E-mail:
SysOp: The Dragon's Cave (Fido 1:343/272, 253-639-9905)
"Our science can only describe an object, event, or living thing in our own
human terms. It cannot, in any way, define any of them..."
Received on Wed Mar 24 1999 - 08:43:57 GMT

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