0 ; ** PROGRAM EXAMPLE 1 **›20 ;PROGRAM SETS UP A VVBLKD ISR›30 ;›40 ; SET UP NEW VECTOR WITH A BASIC USR CALL A=USR(1536)›50 ; NEED TO DO THIS WHENEVER SYSTEM IS RESET›60  *= $600      PUT IN PAGE 6 DECIMAL 1536›70  PLA          NULL VALUE FROM BASIC›80  LDA #7       INDICATOR FOR VVBLKD›90  LDX #06      HIGH BYTE FOR VECTOR ADDR›0100  LDY #$40   LOW BYTE FOR VECTOR ADDR›0110  JSR $E45C     SET UP DEFER›0120  RTS        RETURN TO BASIC›0130 ; **  **  **  **›0140 ; ROUTINE AT DECIMAL 1600 IS DESIGNED TO WASTE TIME.›0150 ; PUT A NUMBER FROM 1 - 5 IN DECIMAL 1568.›0160 ; USE POKE 1568,N›0170 ; THIS IS THE ISR WHICH SIMPLY WASTES TIME.›0180  *= $640›0190  LDX 0         INIT COUNTERS›0200  LDY 0›0210 LOOP1 INX     INCR COUNT›0220  CPX $620      DELAY VALUE›0230  BEQ LOOP2›0240  CLC           FORCE BRANCH›0250  BCC LOOP1›0260 LOOP2 INY›0270  CPY $620      DELAY VALUE›0280  BEQ EXIT      DONE ?›0290  CLC           NO-FORCE BRANCH›0300  BCC LOOP1›0310 EXIT JMP $E93E TAKE NORMAL VBLANK EXIT›