Microsoft KB Archive/46103
SNAP.ASM from MS-DOS Encyclopedia Code Incorrect ID Number: Q46103
3.20 3.21 3.30 3.30a 4.00 4.01 MS-DOS
The SNAP.ASM program listing included on the MS-DOS Encyclopedia Companion Disk contains an error. However, the listing is correct in the printed source code in the “MS-DOS Encyclopedia” book.
To correct the error, change “ax” in the following line in the GetDOSVersion procedure:
mov ax, 30h ;INT 21H function 30H:
Change “ax” to “ah” to match the following line in the middle of Page 377 of the “MS-DOS Encyclopedia” book:
mov ah, 30h ;INT 21H function 30H:
After you change this line, recompile the program.
The following is a fragment of the code from the companion disk with the incorrect line:
GetDOSVersion PROC near ; Caller: DS = seg RESIDENT_DATA ; ES = PSP ; Returns: AH = major version ; AL = minor version ASSUME ds:RESIDENT_DATA
mov ax,30h ; INT 21H function 30H: ; ....etc....