The Liberty Basic Newsletter - Issue #81 - SEP 2000

We now have two or three ways to handle real time looping. Lets compare them. How? Well, we've learned how to do everything we need in this newsletter. :-) So lets put them all together to create ourselves a simple Benchmark program

'------ BenchMark RealTime Loops program
'
' Change these variables to change test timings

times = 5 'how many times to loop
loopTime = 100 'how long you want it to take for each loop
[Check_Version]
    if val(left$(Version$,3)) < 2.0 then goto [V1.4]
[V2.0]
' Using LB2's time$("milliseconds")

open "mmsystem.dll" for dll as #mm
    calldll #mm, "timeGetTime",_
    start as long
for i = 1 to times
    timeNow = time$("milliseconds")
    result=0
    while loopTime > result
        result = time$("milliseconds") - timeNow
    wend
    c = c + 1
    print c
    total = total + result
next i
calldll #mm, "timeGetTime",_
    end1 as long
close #mm
print "Results of test using LB2's time$("+chr$(34)+_
    "milliseconds"+chr$(34)+")"
print "The average milliseconds the dll was delaying for "+_
    "was: " + str$(int(total/times))
print "The average time it took to complete the hole loop was"
print str$(int((end1-start)/times)) + " and should " +_
    "have taken " + str$(loopTime)

[V1.4]

' Sample from Steve on how to use his great new timer.dll
' only Variable names have been altered to change global test
' variable values easily at the top of the program

c = 0        ' resrt the c variable
total = 0    ' reset the total variable to 0
open "call32.dll" for dll as #call32 'open dll
    calldll #call32, "Declare32", _ 'Define call
        "_DELAY" as ptr, _
        "timer.dll" as ptr, _
        "i" as ptr, _
    idtimer as word
    open "mmsystem.dll" for dll as #mm
        calldll #mm, "timeGetTime",_
            start as long
            for i = 1 to times
                calldll #call32, "Call32", _
                    loopTime as long, _'specifying loop length
                    idtimer as long, _
                result as long 'Returns the delay
                c = c + 1
                print c
                total = total + result
            next i
            calldll #mm, "timeGetTime",_
                end1 as long
            close #mm
close #call32
print "Results of test using Steven's timer.dll"
print "The average milliseconds the dll was delaying for "+_
    "was: " + str$(int(total/times))
print "The average time it took to complete the hole loop was"
print str$(int((end1-start)/times)) + " and should " +_
    "have taken " + str$(loopTime)

' using Windows mmsystem.dll

c = 0        ' reset the c variable
total = 0    ' reset the total variable to 0
open "mmsystem.dll" for dll as #mm
    calldll #mm, "timeGetTime",_
    start as long
    for i = 1 to times
        calldll #mm, "timeGetTime",_
        result as long
        newTime = result 'initialize newTime value
        while loopTime > newTime-result
            calldll #mm, "timeGetTime",_
            newTime as long
        wend
        c = c + 1
        print c
        total = newTime+total-result
    next i
    calldll #mm, "timeGetTime",_
    end1 as long
close #mm
print "Results of test using mmsystem.dll"
print "The average milliseconds the dll was delaying for "+_
    "was: " + str$(int(total/times))
print "The average time it took to complete the whole loop was"
print str$(int((end1-start)/times)) + " and should " +_
    "have taken " + str$(loopTime)
'------ End of program

See if you can find any mistakes in the program. :-)
Can you see all that I covered earlier in this newsletter?
Try running the benchmark program.  I'd be interested in seeing the results.
Try altering the values set for :=-

' Change these variables to change test timings:

times = 5 'how many times to loop
loopTime = 100 'how long you want it to take for each loop

at the top of the program. Notice how they differ.

Its up to you which you decide to use.. Just remember: have fun programming :-) 

Till next time, 

Cameron Arnott


Here are the results from my system :-)
1
2
3
4
5
Results of test using LB2's time$("milliseconds"):
The average milliseconds the dll was delaying for was: 110.
The average time it took to complete the whole loop was
103 and should have taken 100.
1
2
3
4
5
Results of test using LB2's time$("milliseconds"):
The average milliseconds the dll was delaying for was: 110.
The average time it took to complete the whole loop was
103 and should have taken 100.
1
2
3
4
5
Results of test using mmsystem.dll:
The average milliseconds the dll was delaying for was: 100.
The average time it took to complete the whole loop was
105 and should have taken 100.