From: Richard Erlacher <edick_at_idcomm.com>
Date: Sat Oct 27 18:19:50 2001

Once the PC came out, I stopped worrying about what would work with what unless
I was hired to worry those matters. Nevertheless, I've got a '386 motherboard
sitting downstairs somewhere that uses a '287 rather than the usual '387. I
didn't buy it for that reason, but I did keep it for that reason. If I'd gotten
enough documentation to explain what was going on, I'd have more info for you,
but with the PC-"standard" falling apart with the release of the '386, because
IBM no longer provided a firm ISA-equipped standard that everyone else could
clone, there was nothing but chaos, and that's the way it's been ever since.
The whole concept of "standard" was corrupted in the course of this evolutionary
step, and it was a step into the quagmire we're all swimming in today.

BTW, if that "bulky old PSU" still works, I'd happily relieve you of the fan and
PSU board, and pay you for the freight, except for where you're located. I find
them harder and harder to get, now that ATX PSU's are taking over, and grab them
whenever I can get them for <$10. The fans don't last forever, and I remember
once commenting that the fan costs $40, the whole PSU $30, the case wth PSU,
$20, and, by rights, the entire PC should therefore cost $10. That's no longer
the case, and, while the whole PC should probably still cost $10, the AT PSU is
a rare bird except in surplus and therefore probably non-functional condition.

The ISA Ram will run at the ISA rate, which is not terribly fast, but it's
normally as fast as the CPU requires. Unfortunately, the ISA clock is a
STANDARD, at 8 MHz, so, even in cases where the CPU runs at 10 or 12 MHz, (I've
got one that runs at 24), the ISA is still limited by that 8 MHz clock.


----- Original Message -----
From: "Iggy Drougge" <optimus_at_canit.se>
To: "Richard Erlacher" <classiccmp_at_classiccmp.org>
Sent: Saturday, October 27, 2001 5:29 PM
Subject: Re: VLB SCSI?

> Richard Erlacher skrev:
> >I saw a '386 motherboard with VLB slots on Tuesday, but didn't bite. It took
> >me WAY too long to give away all my old '386's, and the only one I kept was
> >one that uses a '287 coprocessor, just for interest.
> 287? I didn't think that would be possible. Don't they use different length
> arithmetic, just to name one difference?
> Apropos lower-end PCs, I've got a 286 laying around in the hallway. I was
> planning to recycle its case (Save for the bulky PSUs, old PC cases are
> generally much nicer than modern ones IMO.
> However, I thought I'd have some fun with it for a while, and make a
> contraption like Tony's PC, using the CPU socket upgrades I've scrounged.
> But if I put a 386 upgrade (I've got two, one Intel AboveBoard and another one
> from Nokia) into the 286 socket, how will the clock frequency be derived? Will
> it just take the motherboard frequency and run at 8-10-12-16 MHz, or will it
> multiply it? Or would it run asynchronously from the rest of the board (it's
> obvious that I have no idea what I'm talking about =) using its own frequency?
> BTW, in German, that's Taktfrequenz, IIRC, Erlacher. ;-)
> Then how would one solve the memory issue? Most 286 mobos will use DIPs for
> RAM, and I'm uncertain about their expansion abilities. I also have some
> awfully slow ISA RAM upgrades, but would the new CPU even support that?
> It would make a nice novelty item, at least. =)
> >If you're going to use it as a server, e.g. under Netware, you don't need a
> >hot processor. The disk I/O proceeds via DMA at the rate at which the drives
> >can go, and the network I/O does too. The CPU is idle much of the time,
> >since it really only manages the transfers and handles directories. With one
> >or two people, 4 at the most, even a '386SX-16 would be plenty.
> Not if you're going to put an NE2000 into it. =)
> Here's an interesting page which surveys how different ethernet apaptors will
> push different processors:
> http://john.ccac.rwth-aachen.de:8000/misc/mca_lanperform/
> [snip]
> --
> En ligne avec Thor 2.6a.
> The gates in my computer are AND, OR, and NOT, not Bill.
> --Tony Duell
Received on Sat Oct 27 2001 - 18:19:50 BST

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