Can someone explain the whole "set cpu0 to 25%" thing?
Reply #29 above - Tilde menu.
You can also specify this in the cheat dat file so it does this automatically:
Found a way to over or under clock the CPU without having to press ~ and messing with the CPU speeds every time the game loads. I've tested it on Cruising usa and it seems to work. Edit the cheat.dat file for Cruising usa to look something like this:
; [ Cruis'n USA (rev L2.1) ]
:crusnu21:65004000:00000000:00004500:00000000
:crusnu21:65004000:00000001:00004500:00000000
:crusnu21:65004000:00000002:00004500:00000000
crusnu21:0:003DDA4:0F:000:Infinite Time
crusnu21:0:003DDA5:27:500:Infinite Time (2/4)
crusnu21:0:003DDA6:00:500:Infinite Time (3/4)
crusnu21:0:003DDA7:00:500:Infinite Time (4/4)
These Three lines refer to CPU1,CP2 and CPU3
:crusnu21:65004000:00000000:00004500:00000000
:crusnu21:65004000:00000001:00004500:00000000
:crusnu21:65004000:00000002:00004500:00000000
you can edit "00004500" to show "00020000"
00004500 = CPU clock % of around 27%
00020000 = CPU clock % of around 200%
you'll need to also enable the cheat option in your mame ini file. Also, you can test different values to see what % works best.
I've tested this with Crusing USA with a clock of around "00004500" or 27%. I still get a little slow down, but it does seem to make a difference and it loads the cheat everytime.
Steve
Cheat formula decimal percent * 65536, converted to hex.
25% would be 4000 hex.