|
|
Post by wsoft on May 11, 2024 20:28:09 GMT
Lately I've enjoyed reading posts made by some very brilliant minds. There are still new ideas on the horizon for this machine. I applaud each and every one of you for your contributions because this is the place to go for ideas. This isn't a dream...
The only ones who can turn the popularity of the 8-bit platform for the better exist here. New ideas are out there and the sky is the limit. There is talk about using the Z-80 CPU and that's something as rare as unicorns. But to use it to expand the already-existing capabilities of the VIC-II chip? Only time will tell.
|
|
|
|
Post by c128old on May 12, 2024 9:26:20 GMT
The z80 in the c128 is connected to the IO chips and to the IRQ line. The z80 supports NMI but commodore decided against connecting that. The VIC is an IRQ source, thus the z80 can be made to listen to raster interrupts. People like Steve Goldsmith developed examples of C128-CPM-VIC tricks, see www.youtube.com/watch?v=htmWCC5GO1U&pp=ygUMYzEyOCBjcG0gdmlj , and Steve is porting his libraries to the 'z88k' development environment (a multi-platform C-code Z80 development tool). See raster demo: youtu.be/wdDnGXEhSYcBy Steve's argument: programming in assembler is tedious, using C is an improvement (see his work at github.com/sgjava/c3lz he has created a text-2-speech tool under CPM) I don't expect expanding on VIC-IIe with the Z80, it has no particularly powerful tricks up its sleeve beyond the 8510. That said, the examples elsewhere in this forum showing Z80 VIC-open-border tricks have at least 1 bonus: fixed-timing. The Z80 has a 'halt' instruction making it wait for an IRQ, a problem that requires a 'stable-raster' solution for 6510. The 'clock-stretching' for IO access happens in both CPUs, no gain there either. |
|
|
|
Post by wsoft on May 14, 2024 2:49:48 GMT
I admit thinking hey the Z-80 is just another CPU and the VIC-II is just another chip. But you guys are talking about new things and that is something to be applauded in and of itself. Good luck with that 👍 If the Z-80 can listen in on VIC II interrupts then that's going to be a new can of worms pertaining to timing issues, though. Glad it's you and not me... lol
|
|
|
|
Post by jusalak on May 17, 2024 21:59:44 GMT
I rather see both CPUs as equals. I don't despise 8502, I began with it and I enjoy writing code to it also. But Z80 certainly has a potential to be used and explored.
|
|
|
|
Post by wsoft on May 25, 2024 8:09:33 GMT
I suppose it remains to be seen if raster-splits can actually be accomplished cleanly using a CPU that wasn't really invented for it. And the real hardware will likely never be compatible with emulation.... ever.
|
|
