Gigatron Hackers

You mean, writing above this address may be not safe for some ROMs. I understand. I mean that you should first use the 62 bytes in [0x42-0x7f] because this is safe in all cases I know. Your program can also use [0x36-0x41] but you should not load values into these locations because that interferes ...

This is a tricky question, which depends a lot on the particular ROM. Function `create_zpage_map` in the GLCC linker (see https://github.com/lb3361/gigatron-lcc/blob/29dbb38208aa69690484924beec97e3ff292c8fa/gigatron/glink.py#L522). Here is the summary: A GT1 file should never write to locations 0x00...

Very impressive demo

bmwtcu: I remember your tang nano gigatron. The problem was the same: there is not enough memory in the Gowin 9K FPGA to have a full rom. As for the vga signal, I found a nice explanation https://chipnetics.com/tutorials/understanding-75-ohm-video-signals/ but I do not understand the pros and cons o...

This is a very cool project. Maybe the cheapest Gigatron implementation in fact (about $30 maybe). A question for bmwtcu: I noticed that the adapter board uses level shifters that automatically sense the signal direction, something that I can understand if both ends have the kind of well defined loa...

Makes sense. Pull request on the way for Contrib/lb3361.

Just a question: I have a number of little improvements on the js emulation. Where should I submit them? It does not seem right to make a GitHub pull request into somebody's Contrib code without this person input. Examples: - The js code assumes that native opcode st(...,X) copies the bus into X. In...

Awesome.

Walter:
Allow me to donate a version "emu-mscp" that directly runs Marcel's Simple Chess Program.
This has the RAM&IO board extension emulation and the custom rom.

Also emu-dev7 is an old dev7 rom. You'll find the newest ones in the same tar file if you care.

Here is how this is written in GLCC. The idea is that the byte that follows the SYS opcode should be a negative number whose magnitude is the number of additional ticks needed by the SYS function (in addition to the maxTicks ticks given to all vCPU ops). Therefore the number of cycles given to SYS m...

Using petersieg's zip of April 9th (above in this thread), compiled for dev7, run in mode 3 in gtemuAT67: Screenshot 2024-04-21 at 7.27.04 PM.png Toledo has answered e2e4 after only a few hours. It also work inside http://www.gigatron128k.com, but the problem was that the emulation is suspended when...