; oscilliscope ; ports: 26 output 80 for "mode 0: ; B 20 to output voltage: 00(0V) - FF(5V) ;Peripherals--Oscillosocpe Connect scope ;initialize 8255 for mode 0. required MOV AL,80 OUT 26,AL MOV CX,ffff BigLoop: MOV AL,40 OUT 20,AL call killtime MOV AL,80 OUT 20,AL call killtime MOV AL,c0 OUT 20,AL call killtime MOV AL,ff OUT 20,AL call killtime MOV AL,c0 OUT 20,AL call killtime MOV AL,80 OUT 20,AL call killtime MOV AL,40 OUT 20,AL call killtime MOV AL,00 OUT 20,AL call killtime LOOP BigLoop HLT PROC KillTime MOV DX,4fff burncpu: mul bl ;kill time mul bl mul bl dec DX JNZ burncpu RET hlt