Search found 488 matches

by marcelk
22 Jan 2020, 07:34
Forum: Hardware and software hacking
Topic: Pluggable control unit
Replies: 1
Views: 3346

Re: Pluggable control unit

That's a cool idea! HG has proposed a modified instruction set for his chess program. A cartridge would be neat.
by marcelk
21 Jan 2020, 19:59
Forum: Kit assembly gallery
Topic: Half a night of soldering later...
Replies: 5
Views: 7359

Re: Half a night of soldering later...

ferdy wrote: 21 Jan 2020, 17:50 it took me from 11PM to 4AM in the morning
That reminds me of constructing the breadboard version of what later became the Gigatron (except that there were several such nights over the course of almost two months :D). That was just three years ago now, but seems so far in the past now.
by marcelk
19 Jan 2020, 22:19
Forum: Hardware and software hacking
Topic: I guess I just build a...screensaver?
Replies: 9
Views: 7392

Re: I guess I just build a...screensaver?

As it is now, the clock is 2 seconds off from the start. Just a small detail ;) In the example code, I mitigate this delay by fetching the frame counter immediately following the input: 10 input H,M,S:B=peek(14) This way, the mismatch is reduced to the time it takes for parsing the last user input ...
by marcelk
18 Jan 2020, 20:36
Forum: Hardware and software hacking
Topic: Modified Gigatron Design Ideas
Replies: 57
Views: 53969

Re: Opcode mods

Thanks for clarifying. The only point I tried to make is that if you want to create extra output signals, every flip-flop's output on the board is exposed (as "bare metal you can solder to") and available for tapping into. None are hidden behind a buffer for example, as in many other desig...
by marcelk
15 Jan 2020, 20:17
Forum: Hardware and software hacking
Topic: Expansion bus
Replies: 98
Views: 91237

Re: Expansion bus

[*]don't use the ICSP header since SS is tied to reset and will crash/freeze the Gigatron How does this issue occur? /SS is an output, and should always be driven by the host aka Gigatron. So I don't follow this exactly, and wonder if you have a schematic of what that ICSP header exactly does on th...
by marcelk
09 Jan 2020, 12:09
Forum: Hardware and software hacking
Topic: And I so promised myself... (continued)
Replies: 4
Views: 4460

Re: And I so promised myself... (continued)

Pin handling in BabelFish is localised in low-level functions, or at least it's pretty idiomatic when not. So porting BabelFish shouldn't be too hard. There is a RPi version in Contrib/xxxbxxx/, so it has been done before...
by marcelk
03 Jan 2020, 21:25
Forum: Hardware and software hacking
Topic: I guess I just build a...screensaver?
Replies: 9
Views: 7392

Re: I guess I just build a...screensaver?

Now there's an example program in BASIC/Clock.gtb: 'Keeping time using the '59.98 Hz frame counter 10 input H,M,S:B=peek(14) 20 T=S*60:V=3599:goto 50 30 if T>=V T=T-V: M=M+1 40 if M>59 M=M-60:H=H+1 50 print H;":";M/10;M%10; 60 S=T/60:?":";S/10;S%10 70 A=B:B=peek(14):A=B-A 80 if A...
by marcelk
28 Dec 2019, 00:24
Forum: Hardware and software hacking
Topic: I guess I just build a...screensaver?
Replies: 9
Views: 7392

Re: I guess I just build a...screensaver?

The README.md file in the root of the GitHub repo should be a good starting point. That's where I looked up the address :D
by marcelk
27 Dec 2019, 22:01
Forum: Hardware and software hacking
Topic: Why settle for two BASICs when we can have four
Replies: 0
Views: 11584

Why settle for two BASICs when we can have four

Today we gained two more BASICs... One new, one (very) old. Earlier today, at67 offered his BASIC compiler for the Gigatron. This is a project that has been brewing for more than a year. It's still in alpha-stage (incomplete and no documentation!), but it is GREAT already. This is a cross-compiler t...
by marcelk
27 Dec 2019, 21:23
Forum: Hardware and software hacking
Topic: I guess I just build a...screensaver?
Replies: 9
Views: 7392

Re: I guess I just build a...screensaver?

Thanks! There is an accurate software clock ticking at 59.58 Hz on address 14, but it wraps around every 4 seconds. If you sample it often enough however, you can make a very good clock out of it. The Mandelbrot clock is derived from it.