Clock speed?

[Dinosaur]

Ralph

The only way to use timer tick accurately is to get the interupt to update your variable each time the interupt happens. I use a scheme as below to accurately time events, without creating a lot of overhead.

Code:

'---------------------------------
TYPE TIMES
    Clk        AS    INTEGER
    Divider        AS    INTEGER
    Speed        AS    INTEGER
    Increment    AS    LONG
    Msec        AS    LONG
    NowTime        AS    LONG
    KeyTime                   AS    LONG
    PassCount    AS           LONG
    StartTime                    AS           LONG
    WaitState                    AS    LONG
    RunTime                  AS            LONG
    OldTime                  AS            LONG
    ShowTime              AS            LONG
    Hours                     AS           INTEGER
    Minutes                 AS            INTEGER
    Seconds                 AS            INTEGER
    Tyd        AS    STRING * 7
END TYPE                            
COMMON SHARED TIMES AS TIMES
'---------------------------------
DECLARE FUNCTION TsrTime& (byval a&,byval B&)

'First Hook the Interupt so that everytime the clock tick increments,
'your variable increments.(If you want the asm routine that I can send it)

A& = TsrTime& (byval varptr(Times.NowTime),byval varseg(Times.NowTime))

'I write my programs so that I never hang around or wait for a delay.
'Then at the beginning there is a main loop

DO
    TimeShow
    'call whatever else here,

LOOP

'So if you need an accurate delay.
Times.StartTime = Times.Msec
'then in your loop
IF Times.Msec - Times.StartTime > 12 THEN ......


'You can also use it to see how long your loop takes
'by printing Times.Increment on the screen

SUB TimeShow
        Times.PassCount  = Times.PassCount  + 1        'increment the program loops        
        Times.Msec = clng((Times.NowTime * 54.9254) + (Times.Increment \ 1000 ))    '
        '-----------------------------------------------
        IF Times.NowTime > Times.OldTime  THEN                'if a tick has happened ,recalculate
            Times.Increment  = (54.9254 / Times.PassCount) * 1000     '55 msec / Nr of Passes = msec per pass
            Times.OldTime    = Times.NowTime
            Times.PassCount  = 0
        END IF
END SUB