Gigatron Hackers

Boards are in! They look good on first inspection. Time to start building and testing. Thanks guys for the coupon!

I made a quick cartridge example so I could make sure I didn't make any mistakes with the wiring. Turned out a lot bigger than I expected. I could probably make it smaller with surface mount chips...

My new logic only requires a single extra (4x)OR chip, and I'd rather not have to add another chip. But I think I've figured out a way to have the override to select D on the lower byte without more chips. The problem is that I need an inverter and I don't have one. But I can have effectively an inv...

If the diode logic is really causing that much of a slow down, you could decrease the value of the pull-up resistors. It would consume a lot more current, but that might be a easy tradeoff for speed.

I like this idea. This would change the ST AC -> [X++, X++] instruction to ST AC -> [X++, D] which is much more useful. More instructions for no more chips is good!

You could have a one cable that splits out into the multiple connectors. Or have the cables in a cable wrap, so it looks like one cable. Like this:

https://www.parts-express.com/parts-exp ... k--080-558

I took the store instructions which read and write to/from RAM, and replaced them since they were useless. I kept all the others. Instead those instructions now read from the AC register and then select X as the upper byte (when 0 is not selected). The only really useful one is ST X,D, but there is ...

I don't mean to step on any toes, but I couldn't wait for a Gigatron with a built-in keyboard, so I'm making one myself. The Apple had tons of clones, so it makes sense the Gigatron should have one too. Mechanical keyboards is also a hobby of mine, so I wanted to combine the Gigatron with one. I use...

With the creation of BASIC, I'm thinking of ways to store and load programs. I'd like to be independent of another computer. I think the best medium is something we have on hand these days - our smart phones. We could do what retrocomputers did and use audio medium to store and load programs. We hav...

I wonder if a 74HCT14 would oscillate closer to 50/50 duty cycle. It's still an inverter, but has Schmitt triggered inputs. If you haven't tried it, I will get some and see if there's any improvement.