INT 51 - TI Professional PCIBM PC - RESTART TIMING EVENT AX = timer count in 25ms intervals DS:DI -> timing-event table (see #03244) Note: documented as "for system use only"; intended for multi-tasking software SeeAlso: INT 50"TI Professional",INT 52"TI Professional" Format of TI Professional PCIBM PC timing event table: Offset Size Description (Table 03244) 00h WORD offset of next event table entry 02h BYTE normally unused (FFh) 03h BYTE flags: bit 7 set if timing event active bits 6-0 not used by BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. (0), but could be used by option ROMs 04h WORD timeout count (decremented every 25ms when active) 06h WORD offset of event handler (in segment F400h) to call on event timeout; the F400h segment allows addressing both system ROMs and the first 16K of memory (due to the 1M memory wraparound)