[chbot] Gigatron a 7400-series TTL microcomputer

william fleete fleetwil at gmail.com
Thu Jun 24 11:10:41 BST 2021

There is a series on YouTube by Ben Eater where he builds a micro coded
8bit CPU using standard TTL. I have followed along and built my own
variation and upgraded memory to 256 bytes and designed a few other devices
that work with it, including a typewriter interface

I should bring it along next meeting if you want to check it out

On Thu, 24 Jun 2021 at 21:54, Charles Manning <cdhmanning at gmail.com> wrote:

> Hi All
> All this talk today of smaller computers led me to have a bit of a nosey
> into what's happening in the "crazy CPU world".
> Have any of you looked at this wee CPU?
> https://gigatron.io
> Apart from the ROM and RAM the whole thing is just 74xx logic - 36 74xxs
> in all (including the oscillator)..
> It is a very barebones - 8 bit CPU but with some interesting twists.
> * Each instruction is 16 bits - 8 bit instruction coding and 8 bits
> immediate.
> * 16-bit Harvard address space: 32kx16 ROM, 32k RAM.
> * 8 bit accumulator, X and Y registers.
> They have a software simulator for it that is less than 130 lines long.
> Let the small times roll!
> _______________________________________________
> Chchrobotics mailing list Chchrobotics at lists.ourshack.com
> https://lists.ourshack.com/mailman/listinfo/chchrobotics
> Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/
> Meetings usually 3rd Monday each month. See http://kiwibots.org for
> venue, directions and dates.
> When replying, please edit your Subject line to reflect new subjects.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ourshack.com/pipermail/chchrobotics/attachments/20210624/3dad5588/attachment.html>

More information about the Chchrobotics mailing list