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#int-15h

2 posts

FreeDOSDeep Dive October 3, 2026 7 min read

IBM PS/2 INT 15h C2h: The BIOS Pointing-Device Interface

Use the optional PS/2 BIOS pointing-device service with explicit capability checks, reset semantics, bounded errors, and a clear boundary from INT 33h.

#freedos#dos#bios

FreeDOSDeep Dive October 3, 2026 6 min read

INT 15h C0h: Read the IBM BIOS System Descriptor Safely

Query an AT or PS/2 BIOS system descriptor through INT 15h C0h, validate the far pointer and declared length, and interpret feature bits cautiously.

#freedos#dos#bios