Globalchimes Timing Observations  021605

SwiftForth started full screen for reading microseconds then 
minimized for reading oscilloscope.

Win 98, MAXIMUM priority in BW CPU CONTROLLER. 
Using external trigger on 1PPS rising edge. 

Using NO_DELAY gives 747 to 780 microseconds delay in chimes 
display (max 856 us)
HP180A scope delay is 1.5 milliseconds (1500 microseconds) 
to start of audio waveform.
The display is ROCK_SOLID !  The waveform is INVERTED compared 
to the original.

At 100 ms DELAY: 20 ms/div main, 0.5 ms/div vernier: 
4.935 turns = 98.7 ms to start of waveform.

At 10 ms DELAY: 5 ms/div main, 0.5 ms/div vernier: 
2.050 turns = 10.25 ms to start.
 
Win XP Pro SVC PK 1.
Using MAXIMUM BW CPU CONTROLLER priority gives over 200 ms 
(200000 microseconds) delay with silence 
before start of waveform -- UNACCEPTABLE !!
Using NORMAL priority (after a normal program start) gives 
JUMPY 5, 10, 15, 20 or 25 ms delays with 
silence before start of waveform -- UNACCEPTABLE !!
Using BELOW NORMAL or MINIMUM priority gives stable 4.8 to 5.0 ms 
delays on oscilloscope.

Using NO_DELAY gives 43446 to 4492 microseconds delay in the
chimes display.

At 100 ms DELAY: 104439 to 104923 microseconds delay in 
chimes display, and 20 ms/div main, 0.5 ms/div vernier: 
5.10 turns = 102.0 ms to start of waveform.

At 10 ms DELAY: 10 ms/div main, 0.5 ms/div vernier: 
1.395 turns = 13.95 ms to start of waveform, with a full 
5 ms of silence.

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Timings after dedicating the entire machine to the chimes using: 
START, RUN, typing in MSCONFIG, OK and UNCHECKING ALL STARTUP items 
in WIN 98, or, CHECKING SELECTIVE STARTUP, UNCHECKING LOAD SYSTEM 
SERVICES and UNCHECKING LOAD STARTUP ITEMS, then checking only: 
WINDOWS AUDIO, PLUG & PLAY, RPC LOCATOR and RPC in the SERVICES 
tab in WIN XP.

WIN 98, BW SF.EXE at MAXIMUM priority, 100000 microseconds delay.
Delay in chimes is 99986 to 100066 TWEAK is at 699 rock-solid.
HP180 scope 20 ms/div main, 0.5 ms/div vernier:
4.900 turns = 98 ms to start of waveform (first main positive peak).

WIN XP, BW SF.EXE at MINIMUM priority, 4.885 turns = 97.7 ms.

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The above results are also the same for a newer version of globalchimes.f 
which uses an adaptive tweak of the QueryPerformanceFrequency constant 
to give a precise 1.000000 second period and a precise 100.000 ms delay 
on the SwiftForth display, implying a 2 ms (2%) error in the HP 180A 
oscilloscope. 

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