18 Apr
2000
18 Apr
'00
9:55 a.m.
----- Original Message -----
From: <allisonp(a)world.std.com>
To: <classiccmp(a)classiccmp.org>
Sent: Tuesday, April 18, 2000 7:21 AM
Subject: Re: 8-bit IDE
On Mon, 17 Apr 2000, Richard Erlacher wrote:
<snip>
The S100 systems I have a board of my design and it is
quite simple in
that it buffers address and supplies the low 4 bits of it, a set of
qualified selects, buffered IO_read IO_write, reset/, clock(2mhz), wait/,
interrupts and a bidirectional 8bit bus. This makes IO projects as
trivial as ISA-8 or STD. All brough out on a 50 pin ribbon (alternate
grounds) as a short 1-2ft cable bus. This matches the Visual1050 bus port
(very similar) and the VT180 board I hack with that as a similar mod.
Makes hardware experiementation easy. This is something I implmented
many years ago.
It's not at all strange that you've arrived at that conclusion. I did the
same thing with a channel similar to the WD100x-05 channel, which, by the
way, is normally on a 40-conductor cable with alternate grounds. I even
built one for the XT, back when those were the common box. That, by the
way, is quite somewhat reminiscent of what the IMSAI folks put on their PIO6
board. It's what lives on that little 26-conductor (2x13) in the middle of
their PIO6's top edge. It gives you a channel for external expansion.
Allison