1 *PM CLEAR ROUTINE 2 *A=USR(PMBASE) 3 PMBASL EQU $D4 4 PMBASH EQU $D5 5 ORG $6A0 6 *** TF "D:CLEAR.OBJ" 06A0 68 7 CLEAR PLA ; PULL # OF BYTES OFF STACK 06A1 68 8 PLA ; PULL HI BYTE PMBASE 06A2 85D5 9 STA PMBASH 06A4 68 10 PLA ; PULL LO BYTE PMBASE 06A5 85D4 11 STA PMBASL 06A7 A200 12 LDX #$00 ; PAGE COUNTER 06A9 A000 13 AA1 LDY #$00 ; PAGE BEGINS AT 0 06AB A900 14 LDA #$00 ; LOAD ZERO TO ERASE 06AD 91D4 15 AA2 STA (PMBASL),Y ; STORE IN PM AREA 06AF C8 16 INY ; NEXT BYTE IN MEMORY 06B0 D0FB 17 BNE AA2 ; DO ALL 256 BYTES 18 *AT 256TH BYTE WRAPS BACK TO 0 IN Y REGISTER; FALLS THROUGH 06B2 E6D5 19 INC PMBASH ; DO NEXT PAGE 06B4 E8 20 INX ; UP COUNTER 06B5 E008 21 CPX #$08 ; FINISHED WITH 2K BLOCK 06B7 90F0 22 BL AA1 ; NO, START NEXT 256 BYTE PAGE 06B9 60 23 RTS ; DONE!