Bugbooks - Mark 80

From: Dave Dameron <ddameron_at_earthlink.net>
Date: Mon Jan 25 18:41:10 1999

At 08:03 PM 1/25/99 +0000, you wrote:
>> modem, and most interesting "Bugbook III", 1975 which
>> discusses a MARK 80 (8080) Microdesigner of E&L instruments.
>
>I think I found that book (or maybe another one in the same series) in a
>second-hand bookshop a couple of years back. It's interesting
>historically, but not that useful as (IMHO) it doesn't give enough
>details of the MARK-80 cards.
>
>> This is somewhat interesting as it consists of a backplane
>> with a breadboard area complete with bus connections for
>> interfacing experiments. Bus is called SK-10 and cards plug
>> into dual wide DEC edge connectors.
>
>I found a simpler E&L machine at a radio rally last year. This was a
>single-board (which formed the top of a slope-top case containing the
>PSU) with an 8080, RAM, ROM, keypad, some output ports/LEDs and a
>breadboard on it. I grabbed it, of course.
>
>Alas the ROM is missing. Some kind person here sent me the source/hex
>dump of it, so one day I'll get round to burning a 1702...
>
It is described very well in the April, May 1976 issues of "Radio
Electronics", including circuit description at the IC/gate level, monitor
source, etc.
It doesn't use a 8228, but bus drivers, 1702A's (1 monitor, 1 spare), and
256x4 RAM's (2 expandable to 4). There was a later one with an expansion
box (more RAM, modem/cassette interface), but I didn't buy one, the price
was too high for me US $125.
-Dave
Received on Mon Jan 25 1999 - 18:41:10 GMT