need help with an old ST-251 MFM drive...

From: Richard Erlacher <edick_at_idcomm.com>
Date: Tue Jul 31 12:03:11 2001

I'm with Joe on this one. I can go out any day of the week and buy I/O boards
for $2/dozen, or, certainly, for <$2 and the 8250/16C450/16C550 always costs
more than that. These typically have TWO 8250's or whichever equvalent is used
on them. The risk of damage to these extremely low-quality boards, since they
got to be so cheap by cutting the quality, when unsoldering parts is pretty
great, and, if I were going to do that, I'd probably use a torch, which would
ruin the board anyway, expose me to toxic fumes, etc.

It seems pretty silly to me to spend time and resources fixing a <$1 board when
replacing the IC borders on 10x the cost and inconvenience. It's not a scarce
board like one from an old PDP-5. These things were turned out at rates on the
order 5K per hour, from dozens of vendors and there are still millions of them
lying about in junk boxes everywhere.

If you really like desoldering parts, then your time is better spent salvaging
parts that can be reused rather than desoldering known bad parts. Leave the bad
parts in the board and desolder the good ones. It will be another decade before
PC I/O boards are scarce, so I'm only saving a few.

Dick

----- Original Message -----
From: "joe" <rigdonj_at_intellistar.net>
To: <classiccmp_at_classiccmp.org>
Sent: Tuesday, July 31, 2001 10:31 AM
Subject: Re: need help with an old ST-251 MFM drive...


> At 05:51 AM 7/31/01 +0100, you wrote:
> >Tony Duell skrev:
> >
> > >> > Of course it's easy enough to replace the 8250 with a 16550.
> > Desolder the
> > >> > old chip and pop in the new one.
> > >>
> > >> Or replace the I/O card, or, if you are lucky, it's a dual serial card
> >
> > >Why would _anybody_, particularly on this list, replace a card rather
> > >than replacing a single, easy-to-get 40 pin chip?
>
> Because I can get ALL the cards that I want for free and a chip would
> cost money and the time to install it. Yes, I could chnage the IC but why
> bother? I have better things to spend my time on.
>
> Joe
>
>
>
Received on Tue Jul 31 2001 - 12:03:11 BST