PS/2s nicer than expected; some questions - test-drb@ccmp.vtda.org

24 Mar 1999

Mark Gregory wrote:
...
 Over the weekend I acquired some interesting PS/2
machines: a PS/2 P70 386
portable, and a PS/2 Model 95 XP 486 server. This was my first experience
with the PS/2 family, and I was pleasantly surprised. From what I remember
when PS/2s were new, the media savaged them, mainly due to high price and
the incompatibility with all existing ISA cards, RAM, etc.

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
the ease of configuration of Microchannel cards - better Plug and Play than
with many peripherals on Win 9x machines. 

I quite like them too. My favourite machine (although I don't have much
software installed on it) is a model 76 with a DX2/66 chip, an original IBM
XGA monitor and OS/2 2.1 installed. This combination just seems to work
really well. Not classic yet though.

...

Some questions:

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

I don't think it failed completely. It was widely used in corporate
situations. Not built for the shoestring home market. EISA competed with it
in it's day and avoided an IBM license fee, and later PCI improved on it.

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

ESDI is ESDI, MFM is MFM and IDE is IDE. They don't mix.

...
 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?

That will work fine.

...
 3) I'm having some trouble with the P70.
Originally, it wouldn't boot at
all. I ran the diagnostics from the Reference Disk, and all tests were
passed. I re-ran the Auto Configuration with no errors. I installed PC-DOS
6.3, and formatted the built-in HD at the same time. Everything seems fine,
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? 

Other than basic stuff like not marking the partition active I don't know
about this one. Try checking for bad sectors. Also try fdisk /mbr.