INT 15H: AT Extended Services / APM
INT 15H handles a set of AT-specific services.
AH/AX BIOS Service
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00H Cassette motor ON ═╗
01H Cassette motor OFF ╠═►Oldest PCs only (descriptions
02H read cassette ║ omitted for lack of interest)
03H write cassette ════╝
4fH keyboard intercept
53xxH Advanced Power Management (APM) services
(*) 80H device open
(*) 81H device close
(*) 82H program termination
8300H set event wait interval
8301H cancel event wait interval
84H joystick
(*) 85H SysReq key
86H wait
87H move extended▲ memory block
88H get extended memory size
89H switch to virtual 8086 mode
(*) 90H device busy loop
(*) 91H finish interrupt
c0H get system configuration
(*) services marked with (*) are designed for use with multitasking
operating systems and will only perform the described service if
they have been intercepted by a multitasking operating system.
By default (and when MS-DOS is the active system), these fns
simply clear the Carry Flag and return immediately.
See Also: ROM-BIOS Functions
BIOS Data Area
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