The original CP/M 2.2 for the C64 does not support 2 drives. But you can patch it with a small BASIC program: 1 REM BIOS MODIFICATION 2 REM FOR OPERATION OF 3 REM CP/M MODULE WITH 4 REM TWO DRIVES 5 REM 10 OPEN1,8,15:OPEN2,8,2,"#" 20 PRINT#1,"U1 2 0 1 1" 30 PRINT#1,"B-P 2 249" 40 PRINT#2,CHR$(152);CHR$(12); 50 PRINT#1,"U2 2 0 1 1" 60 CLOSE1:CLOSE2 70 OPEN1,8,15:OPEN2,8,2,"#" 80 PRINT#1,"U1 2 0 1 3" 90 PRINT#1,"B-P 2 152" 100 FOR I=1TO36 110 READ Q 120 PRINT#2,CHR$(Q); 130 NEXTI 140 PRINT#1,"U2 2 0 1 3" 150 CLOSE1:CLOSE2 160 DATA 240,15,162,9,236,159,11,240 170 DATA 24,142,159,11,142,185,11,16 180 DATA 13,162,8,236,159,11,240,9 190 DATA 142,159,11,142,185,11,32,151 200 DATA 11,169,0,96