This little routine will run a NTSC system at PAL speed. It does this by
bypassing the ROM's Display-3 routine, which then allows us to change the
margin value from 31 to 55.
See enclosed text for more info.
Demo video...
https://youtu.be/ZsgqFKky3a0
Regards;
Greg
NTSC2PAL
NTSC2PAL
- Attachments
-
- NTSC2PAL.zip
- Program and support files
- (28.04 KiB) Downloaded 252 times
Re: NTSC2PAL
Impressive!!!
Ernesto
ZX80 USA, ZX81UK, ZX Spectrum, ZX Spectrum+, ZX Spectrum 128+ UK, ZX Spectrum +2/A, Sinclair QL, CZ1000, CZ1500, CZ2000, CZ1000Plus, CZ1500Plus, CZ Spectrum, CZ Spectrum Plus, TK83, TK85, TK90X, TK95. TS2068. And more to come
ZX80 USA, ZX81UK, ZX Spectrum, ZX Spectrum+, ZX Spectrum 128+ UK, ZX Spectrum +2/A, Sinclair QL, CZ1000, CZ1500, CZ2000, CZ1000Plus, CZ1500Plus, CZ Spectrum, CZ Spectrum Plus, TK83, TK85, TK90X, TK95. TS2068. And more to come
Re: NTSC2PAL
I know very little about MC but I guess you are enlarging the amount of the lines in the margin letting more time for the CPU per cycle but not diminishing the active lines in the screen correspondingly in order to keep the Vertical Sync timing. I don't know if that's would be an easy task but it would provide a fantastic way to control speed vs screen in practically any aplication..
Better than a turbo switch.. and keeping compatibility with display systems..
Do you think it is possible?
Better than a turbo switch.. and keeping compatibility with display systems..
Do you think it is possible?
Ernesto
ZX80 USA, ZX81UK, ZX Spectrum, ZX Spectrum+, ZX Spectrum 128+ UK, ZX Spectrum +2/A, Sinclair QL, CZ1000, CZ1500, CZ2000, CZ1000Plus, CZ1500Plus, CZ Spectrum, CZ Spectrum Plus, TK83, TK85, TK90X, TK95. TS2068. And more to come
ZX80 USA, ZX81UK, ZX Spectrum, ZX Spectrum+, ZX Spectrum 128+ UK, ZX Spectrum +2/A, Sinclair QL, CZ1000, CZ1500, CZ2000, CZ1000Plus, CZ1500Plus, CZ Spectrum, CZ Spectrum Plus, TK83, TK85, TK90X, TK95. TS2068. And more to come