Search found 73 matches

by monsonite
31 Aug 2020, 10:07
Forum: Hardware and software hacking
Topic: microtron
Replies: 41
Views: 3174

Re: microtron

Steve, Thanks for the reply. When I first saw the Roelh alu - I was concerned how the ADD function could be achieved from just multiplexers and XOR gates, but after some consideration, a full adder is essentially just two XOR gates and an AND or NAND to provide the final carry out. The problem with ...
by monsonite
30 Aug 2020, 16:54
Forum: Hardware and software hacking
Topic: 80 Column Mode and high speed serial?
Replies: 0
Views: 98

80 Column Mode and high speed serial?

Clearly the original vision for the Gigatron was a 80's retro-style machine with colour video and audio - capable of playing arcade style games. The TTL cpu and integrated video generation hardware was designed around the requirement of 1/4 VGA video generation at 2 bits per colour. What if we took ...
by monsonite
30 Aug 2020, 14:16
Forum: Hardware and software hacking
Topic: microtron
Replies: 41
Views: 3174

Re: microtron

Steve, Not sure how throwing away the full-adders helps at all. Remember that the Roelh design uses 7 ICs to make a 4-bit ALU. The Gigatron achieves an 8 bit ALU in 10 ICs. Moving to the 74xx151 8 input multiplexer may offer some reduction in package count. Remember that the Gigatron can also genera...
by monsonite
05 Jul 2020, 23:24
Forum: Hardware and software hacking
Topic: Overview of hard/software subprojects
Replies: 3
Views: 763

Re: Overview of hard/software subprojects

Walter,

Thank you for summarising these various projects.

As the forum grows, the location of these projects must be a mystery to our new members.

Now we have a list of them all in the one place. - Perfect


Ken
by monsonite
27 May 2020, 09:31
Forum: Escape Meta Alt Control Shift
Topic: In memoriam Marcel
Replies: 16
Views: 4256

Re: In memoriam Marcel

Walter, This is deeply saddening news, and my sympathies go to his family and friends, and of course to the wider Gigatron community. I met Marcel last September at the Cambridge Computing Museum, and have never met such a charming, thoughtful and brilliant engineer. I have had a hardware career for...
by monsonite
15 Apr 2020, 12:33
Forum: Hardware and software hacking
Topic: Conway's Game of Life in Commodore BASIC
Replies: 1
Views: 2658

Conway's Game of Life in Commodore BASIC

As some will know John H Conway - who devised the game "Life" passed away on April 11th. As a tribute, some of our friends on the retrocomputing forum have recreated a version of Life in Commodore BASIC. https://retrocomputingforum.com/t/conways-life-in-basic/1153 I'm going to have a go at getting t...
by monsonite
03 Apr 2020, 21:41
Forum: Hardware and software hacking
Topic: Using a USB keyboard
Replies: 7
Views: 3167

Re: Using a USB keyboard

Hi Dave,

Are you perhaps using one of those USB digital voltage and current meters?

I bought one of them, and found that it dropped a lot of voltage - from 5V to 4.5V IIRC.

If it is in line with the Gigatron supply - try removing it.

That might be part of your problem.


Ken
by monsonite
31 Mar 2020, 16:51
Forum: Hardware and software hacking
Topic: Alternative Languages
Replies: 4
Views: 2351

Alternative Languages

Hi All, I have started this new topic so that alternative languages may be discussed without deviating or diluting the superb content of some of the existing threads. Clearly there is some interest in Forth on this forum - which is excellent, bearing in mind that Chuck Moore was presented a Gigatron...
by monsonite
31 Mar 2020, 16:19
Forum: Hardware and software hacking
Topic: A Forth for Gigatron?
Replies: 14
Views: 9394

Re: A Forth for Gigatron?

Hi, I have been following Ulrich Hoffman and Andrew Read's work for a couple of years. There an interesting paper from the 2018 Euroforth conference that was held in Edinburgh http://www.complang.tuwien.ac.at/anton/euroforth/ef18/papers/hoffmann.pdf The Forth kernel is first dis-aggregated into two ...
by monsonite
03 Feb 2020, 01:20
Forum: Kit assembly gallery
Topic: Built Gigatron with IC sockets
Replies: 6
Views: 3509

Re: Built Gigatron with IC sockets

Hi ECL, I built mine up entirely using sockets too. Rather than glue, I would tack the socket in place by soldering two diagonally opposing pins. Unfortunately I had just one badly soldered joint - so on first power up, operation was intermittent - but with full visual inspection - easily solved. Th...