0320   =   HF_PORT
0000:0034   4   HDISK_INT
0040:0042   1   CMD_BLOCK
     0003   .   DISK_SETUP: JMP SHORT L3
     0005   .   DB '5000059 (C)COPYRIGHT  IBM 1982' ; COPYRIGHT NOTICE
     0023   .   L3: SUB AX,AX
     016E   @   HD_RESET_1