Gigatron Hackers

https://hackaday.com/tag/hackaday-belgrade-2018/

Gigatron starts at 4:59:30

I can't see any issues here, it looks sound, you shouldn't have any issues with fan in/outs, race conditions or meta-stability; but if you want to be 100% sure then you should be able to simulate it in any number of logic simulators without having to breadboard or solder anything; setting up VSync/H...

Added a working GCL example, it shows how to play back MIDI synchronously and asynchronously with respect to VBlank. Example is here: https://github.com/at67/gigatron-rom/blob/master/Contrib/at67/gcl/MidiTest.gcl Documentation is here: https://github.com/at67/gigatron-rom/tree/master/Contrib/at67/mi...

There could be more to it than just aliasing. The reduction from 8 bits accumulated to 4 bits out induces a discretisation error. It might be better to carry over the remainder of this truncation to the next sample, instead of resetting it. Well, all speculation and much tweaking potential. True, a...

I have the nagging feeling that the low-pitch noise might be caused by the mismatch between 521 scan lines and 4 sound channels. Every 16.7 ms there will be an interval of 5, not 4, scan lines that are together producing a sample. That can and will overflow. The solution I had in mind is that the v...

Haven't gotten round to checking this out yet, but I will :) The bassline of the MIDI in that video is off, I remember it being correct in the last one - a new issue, or am I just misremembering? Which track? The title track, (first one), is a different one to the main Tetris theme which starts at ...

I've opened a pull request to fix the build on Windows, but it still didn't just run out of the box - I've not tried it in Linux yet, but I will (I expect the same fixes may be necessary there too, they seem like gcc/real POSIX vs. Mac/clang issues). We can resolve it on github, looking forward to ...

I've updated the Gigamidi tool and the Gigatron's MIDI specification, here's a link to a .gt1 file that uses the new specification; it contains three separate MIDI tracks and a game-over stream, it also runs on Phil's emulator so it should work fine on 32K hardware. Tetris MIDI sample: https://www.d...

I'd like to use at67's, but last time I tried it, the C++17 feature use precluded me from compiling it (and it wasn't a trivial change to fix, so I left it there). If it builds for you though, it has a lot of nice debugging features and instant loading. It should be much easier to build now, I've r...

Here's a couple:

https://github.com/PhilThomas/gigatron
https://github.com/at67/gigatron-rom