The backplanes having more than 8 ISA slots tended to work badly, as a
function of how full and how long they were. Notable exceptions are/were
the 12-slot passive backplanes sold by at least one manufacturer, which
managed to operate quite well. The key is that these were not on a
motherboard and thereby allowed, among other things, placement of the main
CPU close to the center of the backplane while the remaining cards were
installed working inward from the ends.
These things have always been ridiculously expensive due to the low volumes
in which they're produced.
There were a few expansion boxes built with a cable having a bus interface
at each end, capable of converting the differential signals on the cable
betwen them back to single-ended TTL levels. These didn't ever work
particularly well, i.e. were very fussy about what was in the expansion
chassis, as the bus timing was altered by the cable delays.
I wouldn't expect such an item to be low-priced, though, just because of its
relative rarity.
Dick
-----Original Message-----
From: Adam Fritzler <mid_at_auk.cx>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Saturday, October 09, 1999 12:07 PM
Subject: ISA expansion boards/cases
>
>Is there a good place to find boards that plug into a 16bit ISA slot and
>let you have another 8 or so slots? (without building your own)
>
>I would think there'd be a fair number of these floating around now that
>ISA is nearly dead in the mainstream, but aparently not. The
>cheapest I saw one new for $496. Bit ridiculous, imho.
>
>All I need is both end-boards (host end and backplane end) and a
>backplane. (I certainly don't need anymore cases...)
>
>Can anyone help?
>
>af
>
>---
> Adam Fritzler
> { mid_at_auk.cx, afritz_at_iname.com}
> http://www.auk.cx/~mid/
> "Something in my systray is blinking wildly." -- DS
>
Received on Sat Oct 09 1999 - 14:37:59 BST