Classic Computer Rescue Squad

From: Allison J Parent <>
Date: Fri Nov 7 22:46:03 1997

<From: Tony Duell <>

<Intel MCS8i 8080 development system. Well, it was late in the day, my
<money was running out, so I could only buy one of them.

MCS8i, if it was 1972 it could only be 8008 powered as the 8080 was a few
years later. Actually the MCS handle was copyrighted with the 4004. The
8008 was late 1971 and the 8080 a bit over a year later.

<I picked the Intellec. And I am not sorry. Sure it's not going to make me
<rich, but it is _beautiful_ inside. It came with all the manuals
<(schematics and monitor source code), and contains the 8080 CPU board
<(copyright 1972, which must make it a pretty early 8080 design), a couple
<of 4K RAM boards, an EPROM board (1702's, of course) containing the
<monitor, an I/O card, and the programmer for the 1702. The backplane bus
<uses 100 pin 0.125" edge connectors, but the card has a differnt form
<factor (and pinout) to S100 cards

if it was the 100 pin cards (one connector it's the MCS) where the MDS was
multibus with the two backplane connectors. I believe your off on the date
by about two years as the 4004 was 70/71 and the 8008 was first of the
8bitters in late '71 and labeled the MCS-8 and the 8080 was the MCS-80 and
the 8085 followed using the MCS-85. My references are the SIM08/mcs-8 user
manual March 1973. I also I did design work with the 8008 chip in early
'73. The 8080 was not available yet but the intel rep was saying "soon".
It would be nearly 74 before soon arrived.

On the up side yes they were constructed like minis, that was the standard
of the time. Big rugged boxes that had to earn their keep. The MDS I have
is partially gutted as someone pulled the power supplies out but the rest is
intact and last I powered it it ran. FYI the CPU was not even branded in
mine it has some odd penciled ES19-1 on the cpu(8080). I even have the
correct Power One supplies to complete it( same vintage). In time they
could be worth more as they are scarce(low volume production).

<As regards historical interest, well, it has an IOBYTE at address 3,
<divided into 4 2-bit fields that define the console, punch, reader and
<list device - long before CP/M. And there's plenty more things like that.

The first incantation of CPM was on an MDS-800 box and the sources for a
typical bios in the cpm 1.4 and 2 manuals reflect that. IOBYTE is
supported, The docs say it's implemented using the intel standard.

Received on Fri Nov 07 1997 - 22:46:03 GMT

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