Microsoft KB Archive/57541

MS-DOS 4.01 Device Driver Interrupt Information PSS ID Number: Q57541 Article last modified on 02-02-1993 PSS database name: O_MSDOS

4.01

MS-DOS

Question:

In MS-DOS Version 4.01, what software interrupts are available or recommended to use in device drivers such as SCSI host adapters?

Response:

The following is a breakdown of current usage and availability of system interrupts organized by interrupt number. All numbers are in hexadecimal. The only interrupts your software may claim as its own are within the ranges of 60 - 66 and F1 - FF.

Vector # Owner/User/Status ——– —————–

00 - 1F BIOS Vectors 20 - 3F DOS reserved vectors 40 - 5F BIOS and miscellaneous reserved 60 - 66 * USER interrupts *

67 EMS reserved 68 - 6F Reserved 70 - F0 BIOS, BASIC and miscellaneous reserved F1 - FF * USER interrupts *

Additional reference words: 4.01 noupd

Copyright Microsoft Corporation 1993.