Search found 60 matches

by IanB
Thu Aug 06, 2015 9:34 am
Forum: Development
Topic: Time Available For Application Code On ZX81
Replies: 22
Views: 7643

Re: Time Available For Application Code On ZX81

Well, the easiest way to get an answer will be if somebody runs the test program on a real unmodded ZX81 :)
by IanB
Wed Aug 05, 2015 6:46 pm
Forum: Development
Topic: Time Available For Application Code On ZX81
Replies: 22
Views: 7643

Re: Time Available For Application Code On ZX81

Andy, I don't have a real ZX81 available, it would be interesting to see what result my program (above) gives on one. My "target platform" (oh ho!) is a standard, unmodded ZX81, without any improvements, UK version. (There's no way my intended code will get done in the time available on the US versi...
by IanB
Wed Aug 05, 2015 12:17 am
Forum: Development
Topic: Time Available For Application Code On ZX81
Replies: 22
Views: 7643

Re: Time Available For Application Code On ZX81

I will write a personal apology to Americans on my software ;)
by IanB
Tue Aug 04, 2015 7:43 pm
Forum: Development
Topic: Time Available For Application Code On ZX81
Replies: 22
Views: 7643

Re: Time Available For Application Code On ZX81

Well, 18,200 clock cycles per frame multiplied by 50 frames gives about 910,000 or .91 MHz, so they're in the same ballpark. 0.81 Mhz would be about 16,200. Maybe the EightyOne emulator is not quite accurate in this regard. *EDIT* Seeing your edit PokeMon while I was typing my reply, I take it I nee...
by IanB
Tue Aug 04, 2015 6:33 pm
Forum: Development
Topic: Time Available For Application Code On ZX81
Replies: 22
Views: 7643

Time Available For Application Code On ZX81

As mentioned in another thread, I'm re-learning the ZX81. I've been trying from various sources including here to get an accurate measure of how many clock cycles are available to the programmer per frame. So in the end I wrote a short assembly routine to test it. It simply zeroes the BC registers t...
by IanB
Sun Aug 02, 2015 9:09 pm
Forum: Development
Topic: Hello, I'm Restarting ZX81 Programming After... 30 Years
Replies: 37
Views: 11007

Re: Hello, I'm Restarting ZX81 Programming After... 30 Years

It was just to show you how I'd worked out how to set up my own display file ;)

Yes, I know about saving space with unexpanded lines, I'm already planning cunning things with that :)
by IanB
Sun Aug 02, 2015 9:05 pm
Forum: Development
Topic: Hello, I'm Restarting ZX81 Programming After... 30 Years
Replies: 37
Views: 11007

Re: Hello, I'm Restarting ZX81 Programming After... 30 Years

Yes it does. It's just the display file bit at the end that mattered, not the machine code :)
by IanB
Sun Aug 02, 2015 8:50 pm
Forum: Development
Topic: Hello, I'm Restarting ZX81 Programming After... 30 Years
Replies: 37
Views: 11007

Re: Hello, I'm Restarting ZX81 Programming After... 30 Years

Yes, I think I'm getting the hang of it now. I just had trouble getting it to compile when I removed the "include" for the Display File, until I looked at the structure of the files and saw better how they function. This is just a test program (it does nothing of any great use except print to the di...
by IanB
Sun Aug 02, 2015 4:48 pm
Forum: Development
Topic: Hello, I'm Restarting ZX81 Programming After... 30 Years
Replies: 37
Views: 11007

Re: Hello, I'm Restarting ZX81 Programming After... 30 Years

PokeMon, I'm making progress with ZX-IDE, but I am a bit stuck with something. I want to include a "pre-drawn" display file with my program, so it loads in the screen (from which I can copy data at the start) but I can't figure out how to set this in the ZX-IDE. Can you advise please? Edit: It's oka...
by IanB
Sun Aug 02, 2015 11:42 am
Forum: Development
Topic: Hello, I'm Restarting ZX81 Programming After... 30 Years
Replies: 37
Views: 11007

Re: Hello, I'm Restarting ZX81 Programming After... 30 Years

Thanks PokeMon, I'm working my way through understanding and familiarising myself with all this :)