GN_Msc, Miscellaeneous time operations

Register parameters

RST 20H, DEFW $2009

IN:
     A = MT_CVT ($00), Convert source to time to elapse:
     BHL = source time days
     CDE = source time centiseconds/ticks

     A = MT_UBT ($01), Update base time:
     BHL = additional offset in minutes
     C = offset in seconds

     A = MT_UPT ($02), Read uptime

OUT, if A(in) = MT_CVT
	 Fc = 0, success
     	BHL = minutes still to elapse
     	C = seconds still to elapse (only when minutes < 0)
     	A = centiseconds still to elapse
     Fc = 1, failure
     	A = RC_FAIL ($16), time given to routine has already elapsed

Registers changed after return:
     ....DE../IXIY same
     AFBC..HL/.... different

OUT, if A(in) = MT_UBT
	 Fc = 0, always

Registers changed after return:
     A.BCDEHL/IXIY same
     .F....../.... different

OUT, if A(in) = MT_UPT
	 Fc = 0, always
	 DE = days since latest hard reset
	 H = hours, L = minutes and C = seconds

Registers changed after return:
     A.B...../IXIY same
     .F.CDEHL/.... different

Notes

MT_CVT : Operating system uses this call to determine when an alarm has to be triggered by calculating difference between alarm time and current time.
MT_UBT : Applications should not use this call, the system to maintain the time over soft reset. It adjusts the base time because hardware timers are reset.
MT_UPT : Uptime is the operating system running time since latest hard reset. Uptime is preserved over soft reset (OZ V5.0).

Related calls

GN_Gmt, get (read) machine time in internal format
GN_Gtm, convert an ASCII string to a time in internal format
GN_Pmt, put (set) machine time
GN_Ptm, write internal time as ASCII string
GN_Sdo, send date and time to standard output
OS_Dly, delay a given period