tag

#interrupts

3 posts

FreeDOSDeep Dive August 9, 2026 4 min read

The DOS Packet Driver API: One Interrupt Interface for Many Network Cards

How DOS packet drivers expose Ethernet classes, receiver callbacks, send operations, handles, interrupt vectors, and hardware-specific configuration.

#freedos#networking#packet-driver

FreeDOSDeep Dive July 9, 2026 7 min read

Understanding Interrupts on FreeDOS: INT 21h and the DOS API

A register-level guide to the interrupt vector table, FreeDOS INT 21h dispatch, file and process calls, Carry Flag errors, BIOS services, TSR hooks, and reentrancy.

#interrupts#dos-api#freedos

FreeDOSDeep Dive July 9, 2026 8 min read

TSR Programs: How DOS Ran Background Tasks Without Multitasking

A forensic guide to DOS TSR residency, interrupt hooks, chaining, INT 28h and InDOS reentrancy, multiplex IDs, memory ownership, safe unloading, and testing.

#tsr#freedos#dos