FiftyMsecTick Variable (ROM Call 0x4FC)

AMS 2.00 or higher system.h

volatile unsigned long FiftyMsecTick;

A counter incremented by the system auto-int 5 routine.

FiftyMsecTick represents the number of times AUTO_INT_5 was executed since the last reset.
Indeed, this variable is changed only by a routine called at reset, and by the system routine for auto-int 5.

This variable is a way to measure a delay, without using a system timer with OSFreeTimer, OSRegisterTimer, OSTimerCurVal, OSTimerExpired, and OSTimerRestart.

Note also that unlike all the other system timers, FiftyMsecTick is a countup timer.