Search found 60 matches
- Sat Aug 08, 2015 10:27 am
- Forum: ZX Spectrum Lounge
- Topic: Guys, can you tell me what these numbers mean?
- Replies: 10
- Views: 6693
Re: Guys, can you tell me what these numbers mean?
That appears to be the right answer!
- Fri Aug 07, 2015 10:05 pm
- Forum: ZX Spectrum Lounge
- Topic: Guys, can you tell me what these numbers mean?
- Replies: 10
- Views: 6693
Re: Guys, can you tell me what these numbers mean?
I'm just thinking it's hard to even guess, without knowing how the whole engine works. What happens if you change these bytes? You can sometimes find out what something does by breaking it, if you see what I mean.
- Fri Aug 07, 2015 10:02 pm
- Forum: Development
- Topic: Open source utility to perform WAV->P conversion for ZX81
- Replies: 20
- Views: 16829
Re: Open source utility to perform WAV->P conversion for ZX8
Welcome Miguel!
- Fri Aug 07, 2015 1:56 pm
- Forum: Software
- Topic: VULCAN EXPANSION PACK - now with even MORE content
- Replies: 4
- Views: 12222
Re: VULCAN EXPANSION PACK - now with even MORE content
This must have been a major project Daniel!
- Fri Aug 07, 2015 12:35 am
- Forum: Development
- Topic: Executing code in extended memory
- Replies: 20
- Views: 6297
Re: Executing code in extended memory
Well, I haven't tested this, but I think the problems would only occur if you did editing in BASIC on the machine and it called the MAKE-ROOM routine in the ROM that shifts the display file, variables area etc. I have done an experiment of having the machine flip between two display files on each fi...
- Thu Aug 06, 2015 10:42 pm
- Forum: Development
- Topic: Executing code in extended memory
- Replies: 20
- Views: 6297
Re: Executing code in extended memory
Come to think of it, if you've got more than 16K I presume you could just move the whole Display File up above 16K, and have another 793 bytes available for program code
- Thu Aug 06, 2015 9:31 pm
- Forum: Development
- Topic: Executing code in extended memory
- Replies: 20
- Views: 6297
Re: Executing code in extended memory
If you're not using BASIC, I don't see much point in fiddling about with RAMTOP. You can just use the memory as you like above the display file so far as I can tell as a flat memory space (up to the 16K barrier anyway). You can even have multiple display files come to that, or a "long" display file ...
- Thu Aug 06, 2015 1:26 pm
- Forum: Development
- Topic: Executing code in extended memory
- Replies: 20
- Views: 6297
Re: Executing code in extended memory
I wonder if there was a better engineering solution to "Jim Westwood's Problem" for the same price in 1981 that could have been achieved. For instance, not limiting memory to 16k, allowing code execution in all the side screen margins, etc.
- Thu Aug 06, 2015 12:15 pm
- Forum: Development
- Topic: Time Available For Application Code On ZX81
- Replies: 22
- Views: 7713
Re: Time Available For Application Code On ZX81
Yes, I'm working lo-res and the standard display. The intention is full screen graphics in 1K, among other things. This means judicious use of short lines
- Thu Aug 06, 2015 11:54 am
- Forum: Development
- Topic: Time Available For Application Code On ZX81
- Replies: 22
- Views: 7713
Re: Time Available For Application Code On ZX81
Well I'm targetting 16000 at the moment. It's quite crucial to me because I need a dynamic display file, and moving bytes takes a lot of clock cycles :( 21 per byte for an LDIR, you can shave some off with an LDI block and fewer loops, like LDI LDI LDI LDI jp pe, LOOP -that is 18.5 clocks per byte, ...