Posted By
Litwr on 2016-12-26 09:31:27
| Re: Porting to Commodore Plus 4 of my game Genius, memory/bitmap mode questions..
IMHO it is easy to use 64 KB RAM permanently. Just make IRQ and KERNAL calls wrappers. For example, IRQ wrapper maybe something like the next code
bintr STA $FF3E ;enables ROM STA *+11 ;saves AC LDA #>rintr PHA LDA #<rintr PHA PHP LDA #0 PHA TXA PHA TYA PHA JMP ($314) ;ROM IRQ handler rintr STA $FF3F ;turn RAM on RTI
You should place bintr address to $fffe.
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