Date   : Tue, 24 Apr 1984 15:10:00-PST (Tue)
From   : pur-ee!uiucdcs!ea!mwm@Ucb-Vax.ARPA
Subject: Re: 8086 co-processors for CPM80

Not being able to reply to the ARPA-Net (and it's my fault - I have to fix
the sendmail tables....), here we go:

First, I have nothing but praise for the HSC hardware. It works exactly as
advertized. It took less than 15 minutes to install. The z80 runs sits on a
short (~2 in) cable from the old socket. I've had no problems with that.
Doing the I/O through the z80 does make it slower. I can tell the
difference in typing a file on the z80 versus the 68000 (yes, I got the
68000 version). However, this is part of the cost of getting a 16-bit
system for cheap. Given the Intersystems caching BIOS (I'm running an II
MPU-II with 160K), the result is acceptable. This system does output lots
of RFI. The fix for that is in the works. It's nothing more than a shielded
cable, so I don't think there's anything to worry about. This may not be a
problem for you, though.

I've have the 68000 version, so I can't vouch for their MS-DOS
implementation.  The software isn't quite as good as the hardware. Most
noticeably, the BIOS looses disk directories if you have a high performance
BIOS (like the II BIOS. sigh). The fix is supposedly out, but I haven't
seen it. Their are several other problems in the software. All the ones I
know of are supposed to be fixed in the version I haven't seen (I'm going
to call them tomorrow.  I'll post the results).

I've been impressed by their response to customer my problems. The first
set of software they sent me had a bum disk. Ditto for the next *two*
replacement disks. They sent me - quickly - replacements each time. I
complained about the RFI problem, and they sent me the parts I requested
for a fix.

All in all, I'm impressed by the system. It's a very cost-effective way to
get into 16-bit systems. One of the nicest features is that you can still
use all your 8-bit software without having to support two systems (space,
power, disks, etc). CP/M-68K has problems, but my old DDSS disks work like
a charm. Highly unlikely if I'd bought a new system.

       <mike