INT 15 U - OS HOOK - ROM BIOS TRACING CALLOUT (PS30/286,PS50Z,PS95)
AH = C5h
AL = interrupt being invoked
01h INT 19
02h INT 14
03h INT 16
04h INT 40 (floppy INT 13)
05h INT 17
06h INT 10
07h INT 12
08h INT 11
09h INT 1A
Return: all registers except AX must be preserved
Notes:  called as the very first action of the indicated ROM BIOS interrupt
handlers on the PS/2 Models 30/286, 50Z, and 95
default handler does nothing and returns CF clear for the above
subfunctions, CF set and AH=86h for all other subfunctions
value of AX passed to the original interrupt handler is pushed on
stack immediately prior to call


15C5 - OS HOOK - ROM BIOS TRACING CALLOUT (PS30/286,PS50Z,PS95)