DOS ain't dead

DOS kernel debugging (Announce)

posted by Japheth , Germany (South), 29.04.2025, 05:14

Hello,

while playing with the "boot" variant of Debug, I realized that the MS-DOS v7.1 kernel ( Win 98 SE ) can be convinced of not touching interrupt vectors 1 and 3 if signature "JP" is located at [CS:IP-2] of vector 1. Thus the debugger remains active until the cmd prompt appears.

Is this some kind of "standard", also used by other DOS kernel variants? Found nothing about that in RBIL.

---
MS-DOS forever!

Complete thread:

• DOS kernel debugging - Japheth, 29.04.2025, 05:14 (Announce)
  • DOS kernel debugging - ecm, 29.04.2025, 09:59
    • DOS kernel debugging - Japheth, 30.04.2025, 08:20