Gigatron Hackers

If I understand the previous correctly, then it should be no problem to provide the data of A8..A14 on a port with an additional GAL in the IO expander. This is sufficient to supply the 4 blinking lights (for the 8 bit audio extension) and the video mode switching of the video repeater there would b...

I have been looking around for available IC's from local suppliers. There is the DAC0808LCN, TLC7524 and TLC7528CN which I get here for 2,50 to 6,00 €. The next one is the AD558JN for 27,52 (Reichelt), too expensive. The DAC0808 needs a second negative operating voltage (could be provided with somet...

great work, thanks!

I also thought of stm32duino, the code could be taken 1:1. The software for the USB keyboard is not that simple I think. I've only found one example of it so far, but haven't had time to try it out yet. The second thing would be the connection to a PC (USB->serial) would be nice if the STM could do ...

I've been thinking about a Pluggy Reloaded 2 based on an STM32 for a while now. I still have a "Blue Pill" with the STM32F103C8T6 lying here (bought a long time ago for 2$). The chip has 2x USB and at least one of them is host capable, which means you could connect a USB keyboard directly....

Yes I can add a few more LED's for different signals, that is also useful for troubleshooting. I really only have the MCP23S17 on the expansion for one reason, to have the ability to switch video modes (3/4 lines) via software. I have read through the "Expansion bus" post (https://forum.gi...

Thanks for the information. I will deal with it and try to realize a feasible solution for it. (the parts mentioned above don't really seem to be available). Since the audio expansion is autonomous (independent of the expansion board) I will design two separate PCB's that fit side by side and can be...

A circuit for a test board, with 8 bit audio, might look like this: I still want to test it. If it works I will integrate it on the expansion board.
IC2 is the adapter to the Gigatron.

Here is an intermediate stand. I have tested the prototype of the current board. Except for the two missing GND connections, which I fixed with two wires on the bottom, everything seems to work. I've attached a few quick cell phone pictures. A short cell phone video can be found here: https://www.yo...

With the 100mm x100mm limit, I was referring more to the price at the PCB manufacturer. For me, this is not really decisive, but for the wider distribution, I think so. I currently have JLCPCB manufacture, there it does not hurt so "hurt" if one has made a mistake. My first version of the ...