*PM CLEAR ROUTINE *A=USR(PMBASE) PMBASL EQU $D4 PMBASH EQU $D5 ORG $6A0 *** TF "D:CLEAR.OBJ" CLEAR PLA ; PULL # OF BYTES OFF STACK PLA ; PULL HI BYTE PMBASE STA PMBASH PLA ; PULL LO BYTE PMBASE STA PMBASL LDX #$00 ; PAGE COUNTER AA1 LDY #$00 ; PAGE BEGINS AT 0 LDA #$00 ; LOAD ZERO TO ERASE AA2 STA (PMBASL),Y ; STORE IN PM AREA INY ; NEXT BYTE IN MEMORY BNE AA2 ; DO ALL 256 BYTES *AT 256TH BYTE WRAPS BACK TO 0 IN Y REGISTER; FALLS THROUGH INC PMBASH ; DO NEXT PAGE INX ; UP COUNTER CPX #$08 ; FINISHED WITH 2K BLOCK BL AA1 ; NO, START NEXT 256 BYTE PAGE RTS ; DONE!