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)