Search found 376 matches

by lb3361
01 Aug 2024, 13:21
Forum: Hardware and software hacking
Topic: TTL Loaders and Zero Page
Replies: 4
Views: 4749

Re: TTL Loaders and Zero Page

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 ...
by lb3361
30 Jul 2024, 23:16
Forum: Hardware and software hacking
Topic: TTL Loaders and Zero Page
Replies: 4
Views: 4749

Re: TTL Loaders and Zero Page

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...
by lb3361
12 Jul 2024, 23:31
Forum: Hardware and software hacking
Topic: Another FPGA Gigatron implementation
Replies: 6
Views: 5289

Re: Another FPGA Gigatron implementation

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...
by lb3361
09 Jul 2024, 12:37
Forum: Hardware and software hacking
Topic: Another FPGA Gigatron implementation
Replies: 6
Views: 5289

Re: Another FPGA Gigatron implementation

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...
by lb3361
06 Jun 2024, 13:04
Forum: Hardware and software hacking
Topic: online gigatron emulator and CSP errors
Replies: 9
Views: 6584

Re: online gigatron emulator and CSP errors

Makes sense. Pull request on the way for Contrib/lb3361.
by lb3361
05 Jun 2024, 16:54
Forum: Hardware and software hacking
Topic: online gigatron emulator and CSP errors
Replies: 9
Views: 6584

Re: online gigatron emulator and CSP errors

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...
by lb3361
04 Jun 2024, 22:51
Forum: Hardware and software hacking
Topic: online gigatron emulator and CSP errors
Replies: 9
Views: 6584

Re: online gigatron emulator and CSP errors

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.
by lb3361
04 May 2024, 22:34
Forum: Hardware and software hacking
Topic: SYS functions cycles problem
Replies: 2
Views: 5395

Re: SYS functions cycles problem

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...
by lb3361
21 Apr 2024, 23:30
Forum: Hardware and software hacking
Topic: Toledo chess program
Replies: 12
Views: 11767

Re: Toledo chess program

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...