Subject: Re: simple pdp 'type' computer

From: [email-masked] (Stephen Quigg)
Date: Thu, 2 Jun 1994 22:49:28 GMT

In article <[email-masked]>,
Stephen Walters <[email-masked]> wrote:
>Does anybody have any article, books, FAQ's, plans for a serial bit 
>computer or similar 'simple' machines that can be construted with only 
>transistors, ttl 74ls chips or 4000 series CMOS?
>
>This machine would be made of ??? 100+ gates ??? use cassette or acoustic 
>delay line for storage.
>
>And....absolutly NO microprocessors
>Any suggestions
>
>
>[email-masked]

 Here in OZ we have a magazine called "Electronics Australia", and it featured
a simple 8-bit machine based on the PDP-8 architecture; it was called "EDUC-8"
(obviously derived from "educate", which shows the intention of the machine).
The series was as follows;

Aug 74	EDUC-8 digital microcomputer - 1: Introduction
Sep 74	EDUC-8 microcomputer - 2: How it works
Oct 74	EDUC-8 microcomputer - 3: Starting construction
Nov 74	EDUC-8 microcomputer - 4: 3 more sections
Dec 74	EDUC-8 microcomputer - 5: Getting it going
Jan 75	EDUC-8 microcomputer - 6: Input/output interface
Feb 75	EDUC-8 microcomputer - 7: Programming
Mar 75	EDUC-8 microcomputer - 8: Interfacing with tape
Apr 75	Interfacing EDUC-8 with a Philips 60SR printer unit
May 75	A full ASCII-type keyboard for the EDUC-8
Jun 75	Teaching your EDUC-8 to play a melody
Jul 75	Interfacing EDUC-8 to teleprinters and magnetic tape
Aug 75	Interfacing a Burroughs Self-Scan display panel to your EDUC-8

I can't remember the details of this machine except that it was based on TTL
logic and had (very small) sollid-state memory. At the time it was a very 
interesting project, and was almost the first computer construction article
anywhere. But today, 32 or 256 bytes of memory is considered a little on the 
small side. The theory of operation is probably still a good read, and finding 
one (or buiding one if there are still any kits lying around somewhere) would 
be interesting from a historical point of view. The cover of one magazine 
showed the author demonstrating the EDUC-8, and in the background were a couple
of "straight-8" systems that were used by the publishing company at the time. 
Apparently some "lunch time" hours on these machines were the stimulus for the
EDUC-8 project. (And I have some DECtapes that came from that company, and may 
have even been used on the same machines, but that's another story).

Cheers,
Steve Quigg.

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From: [email-masked] ("Stephen Walters")
Date: Tue, 7 Jun 1994 00:06:07 GMT

Do you know where any copies of this magazine could be acquired? or 
copies of the articles