480 CLS:GOSUB130:CLS:GOSUB500:GOSUB130:Y$="9":Z$="5":X=-1:Y=-1:Z=59:GOSUB370:GOSUB260:TS=VAL(MID$(T$,7)):TM=VAL(MID$(T$,4,2)):TH=VAL(MID$(T$,1,2)):IFTS=0ANDTM=0ANDTH=0THENCLS:PRINT@0,"Can't count down from 0"CHR$(7);:GOTO80
490 GOTO300
500 PRINT@102,DT$:KEYON:PRINT@80,"Enter the ";:LINEINPUT"start time: ";T$:IFT$=""THENT$=DT$