What is the poke to turn a C128 to 2MHz in C64 mode?
Moderator: Moderators
What is the poke to turn a C128 to 2MHz in C64 mode?
/Anders
PRG Starter - a VICE helper / Vic Software (Boray Gammon, SD2IEC music player, Vic Disk Menu, Tribbles, Mega Omega, How Many 8K etc.)
Great! Thanks!
/Anders
/Anders
PRG Starter - a VICE helper / Vic Software (Boray Gammon, SD2IEC music player, Vic Disk Menu, Tribbles, Mega Omega, How Many 8K etc.)
True, but if you're programming in assembly, you can set up raster interrupt routines that switches to 2MHz at when the raster beam reaches the bottom border, and back to 1MHz when it reaches the start of the screen. Should give you the equivalent of 1.5MHz or so.carlsson wrote:However, since the other chips are not 2 MHz compliant, I think the screen will go blank and the I/O ports will not work until switching back to 1 MHz.
Try out Elite 128 (a version of the classic game Elite modified to run on a 128 in 64 mode) to see the difference in speed when this technique is used. It can be switched between 1MHz and 2MHz in-game, so it's easy to see the effect on the vector graphics animation.
Bacon
-------------------------------------------------------
Das rubbernecken Sichtseeren keepen das cotton-pickenen Hands in die Pockets muss; relaxen und watschen die Blinkenlichten.
-------------------------------------------------------
Das rubbernecken Sichtseeren keepen das cotton-pickenen Hands in die Pockets muss; relaxen und watschen die Blinkenlichten.
It didn't work in basic! It works in ML in 64 mode and in basic in 128 mode (and of course probably in ML in 128 mode), but the moment you do that poke in basic in 64 mode, then everything stops! Any idea why?
/Anders
/Anders
PRG Starter - a VICE helper / Vic Software (Boray Gammon, SD2IEC music player, Vic Disk Menu, Tribbles, Mega Omega, How Many 8K etc.)
Isn't that much like how the Plus/4 and C16 work?Bacon wrote:True, but if you're programming in assembly, you can set up raster interrupt routines that switches to 2MHz at when the raster beam reaches the bottom border, and back to 1MHz when it reaches the start of the screen. Should give you the equivalent of 1.5MHz or so.
C128, C128D, C64, C64C, ABC80, ABC800, ABC806, 130XE, ZX81, Spectrum 48k, Dragon 32, TI99/4A, Laser 200, Spectravideo 328, Sord M5, VIC20...