10 .TITLE MOVE OS TO RAM 20 .OPT OBJ 30 * = $8000 40 START LDA #0 50 STA $022F 60 STA $D40E 70 STA $D20E 80 SEI MAKE SURE NO 90 LDA #$C0 INTERRUPTS 0100 STA $C1 SET UP BANK AREA 0110 LDY #0 0120 STY $C0 0130 L3 LDA <$C0) ,Y GET ROM BYTE 0140 TAX 0150 LDA #$FE 0160 AND $D30 1 0170 STA $D30 1 BANK TO OS RAM 0180 TXA 0190 STA <$C0) ,Y STORE BYTE 0200 LDA #$01 0210 ORA $D30 1 0220 STA $D30 1 BACK TO ROM 0230 INY GET READY NEXT 0240 CPY #0 0250 BNE L3 256 TIMES 0260 NOK INC $C1 0270 CLC 0280 LDA $C1 0290 CMP #$D0 0300 BCC T1 FROM $C0-$FF 0310 CMP #$D8 SKIP $D0-$D7 0320 BCC NOK 0330 T1 CMP #$00 0340 BNE L3 0350 CLC 0360 LDA #$FF 0370 STA $D40E 0380 LDA #$F7 0390 STA $D20E TURN ON NMI , IRQ 0400 LDA #$22 0410 STA $022F 0420 CLI 0430 RTS 0440 .END