Title [lDOS] Device interrupt entry crash or error if DN (Direction Flag set)
AuthorE. C. Masloch
Created2026-06-22 14:05:28 +0200 Jun Mon
State closed

lDOS msbio/code.asm doesn't clear the Direction Flag on its entrypoint. However, the device entry assumes that it is cleared. Non-device entries (eg int 21h handler) are unaffected by this bug.

E. C. Masloch on 2026-06-22 14:13:40 +0200 Jun Mon

Fixed in hg 333785fe3ea8 today.

E. C. Masloch on 2026-06-22 14:18:29 +0200 Jun Mon

Bug in hg 4fb5b4b370dd on 2025-01-19, albeit the device entry path wasn't used until hg 190282ca5fba on 2025-08-19.