MEM 0040h:0040h - DISKETTE - MOTOR TURN-OFF TIMEOUT COUNT                       
Size:	BYTE
Desc:	number of clock ticks until diskette motor is turned off
Note:	the typical implementation of the timeout is to have the INT 08 
	  handler decrement this byte on every clock tick, and force the
	  diskette motor off if the result is equal to zero
SeeAlso: MEM 0040h:003Eh,MEM 0040h:003Fh,MEM 0040h:0041h,INT 08"IRQ0"