10 REM SYS REGISTER PASS EXAMPLE
20 REM A/X/Y VALUES GO THROUGH 780/781/782
30 POKE 780,65:REM PETSCII A
40 POKE 781,66:REM PETSCII B
50 POKE 782,67:REM PETSCII C
60 SYS 49152
70 PRINT:PRINT "RETURNED A,X,Y=";PEEK(780);PEEK(781);PEEK(782)