Date   : Fri, 09 Oct 1987 06:40:11 GMT
From   : eris!mwm@jade.Berkeley.EDU (Mike (My watch has windows) Meyer)
Subject: Re: 8 bit S-100 update to 16 or 32 bit

In article <4347@ozdaltx.UUCP> bill@ozdaltx.UUCP (Tic-Toc's battery is
run down) writes:
<I am looking for information and suggestions for upgrading my IMS
<8000 system to either 16 or 32 bit operation.  Cost being the
<main factor.  This is an older, non DMA machine with 3 full size
<Qume DT-8 drives and an 8" 40 meg hard disk.  I know that I would
<probably have to dump all of these, and start fresh with all new
<boards.   Any Suggestions?   
<
<BTW, this is a IEE-696 system.

I'm not familiar with the IMS line - or only vaguely so. I'm going to
work on the assumption that it's similar to other S-100 boxes.

Since it's an IEEE-696 system, I assume that all your boards are IEEE.
Given that, the # of routes you can go depend on how much work you're
willing to do to upgrade.

First comment - you won't be able to go to "real" 32 bit operations.
IEEE-696 has hard limits of 16 data bits, and 24 address bits.  You
might be able to find someone with a 32-bit S-100 card that deals
16-bit data, but I'd be surprised.

Route 1, the high road. Buy a card set from some S-100 company, tweak
it to talk to your drives. Shouldn't be to painful. Finding the
company is the hard part. I'd try Viasyn, as they appear to be the
best company still in the S-100 business (or in business the last time
I looked).

Route 2, the low road: Buy a cpu-card only, and write the drivers you
need for it to talk to your disk controllers. Not recommended unless
you're into writing device drivers or are a masochist.

Other options live between the two - like buying only CPU, FDC and
serial card - or skip the serial card if you can find an FDC with a
spare serial line. Use that to get the system running on the floppies,
and then write your own hard disk driver.

The nasty part of this is that, as of the last time I looked, the cost
of one card (new) was about the cost of a low-end "appliance" 16-bit
system. For instance, you can get an Atari ST 512 for ~ $400, the
Amiga A500 for ~ $600, or an IBM PC clone for ~ $500. Given that, I'd
be seriously tempted to sell the IMS system (sans the HD) for what you
can get for it, and buy one of the above (I like the Amiga, but the
others might be better for your purposes) plus a controller for the
HD.

That is the route I finally took. The Amiga was almost exactly the
hardware configuration I was looking for, didn't have the flakiness of
five-year old hardware, and had *much* nicer software than I could get
for the S-100 hardware. Plus spiffy graphics/sound/mouse.

       <mike
--
The weather is here, I wish you were beautiful.                Mike Meyer
My thoughts aren't to clear, but don't run away.       mwm@berkeley.edu
My girlfriend's a bore, my job is to dutiful.          ucbvax!mwm
Hell nobodies perfect, would you like to play?         mwm@ucbjade.BITNET