| FiftyMsecTick | Variable (ROM Call 0x4FC)

AMS 2.00 or higher | system.h

volatile unsigned long FiftyMsecTick;

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

FiftyMsecTick represents the number of times the standard system AUTO_INT_5 routine was executed since the last reset, if FiftyMsecTick was not modified. 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.
Partially emulating FiftyMSecTick on AMS 1.xx is easy with the functions from intr.h. However, to fully emulate the functionality, a memory-resident (TSR) program has to be installed.