TTL homebrew CPUs

[Allison]

>
>Subject: Re: TTL homebrew CPUs
>   From: "Chuck Guzis" <cclist at sydex.com>
>   Date: Sat, 07 Jul 2007 13:16:48 -0700
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On 7 Jul 2007 at 21:38, Lars Hamren wrote:
>
>> The first computer built by Computer Automation, circa 1967, was the
>> PDC 808. It was an 8-bit TTL-only machine with a very basic
>> instruction set. In "Computer Technician's Handbook" Brice Ward
>> describes tat machine in great detail. Should be enough to build a
>> replica from.
>
>Wasn't there an article in one of the magazines (Byte, 
>Microcomputing, Kilobaud???) where a fellow gave details about 
>constructing his own TTL 8080 CPU?  

Check Mick and Brick on Bit slice design and implmentation of an 8080 
in bitslice. Actually 8080 is easier if you are not trying to create
a peice of hardware that results in a 40pin plug to replace an 8080.
By that I mean something that would run 8080 programs but not 
electrically compatable and may be slightly different timing.

There was also a 16bit CPU in Byte, plus there were articles on
TOY (minimalst machine) and further articles on microprogrammed vs
hard wired logic.  The 16 bitter was EGO in the September 1985 issue
(part 1, Part2 is October '85).  So there is another fairly simple 
machine of very buildable proportions with a better than most 
instruction set.


Allison

>
>Cheers,
>Chuck