\ Globalchimes -- Sounding chimes via parallel port I/O interface to GPS -- 26-May-05
\ C:\ForthInc\SwiftForth\GlobalChimes                  (C)                   globalchimes at yahoo dot ca

\ *** Changes 01-16-05 added microsecond period and microsecond delay displays
\ *** Changes 01-20-05 added initial UTC delay message
\ *** Changes 01-21-05 corrected calculations for headphones delay to 105100 microseconds ( 5.6' to ear level/1.087467'/ms)
\ *** Changes 01-22-05 added print_radio_delay and print_sound_delay words in calc_delay.f
\ *** Changes 01-23-05 added stubs for future radio controlled clock experiments, changed headphones to 105149 microseconds
\ *** Changes 01-28-05 reduced chimefour.wav amplitude to 80 % as chimefour_80.wav and 50% as chimefour_50.wav
\ *** Changes 01-29-05 changed delay call after chimefour starts from MS counter to US counter to lock out other tasks
\ *** Changes 01-30-05 allowed other tasks to run for 300 ms after GPS routine ends
\ *** Changes 01-30-05 moved delay time calculation to include time to call SOUNDCHIME which varies between Windows versions
\ *** Changes 01-30-05 added variable windows_delay to tweak utc_tickdelay to compensate for Windows Sytem lag
\ *** Changes 01-31-05 added variable tweak and a circular buffer to nudge actual delay towards desired delay
\ *** Changes 02-02-05 clipped tweak variable at +-200000
\ *** Changes 02-03-05 made chimefour_50_inverted.wav for some systems that flip the audio phase
\ *** Changes 02-04-05 factored out period and delay displays to enable use without a serial cable
\ *** Changes 02-15-05 added notes about using START, RUN, MSCONFIG to disable startup processes
\ *** Changes 02-19-05 added period_tweak to nudge PerformanceFrequency once so the PERIOD is exactly 1000000 microseconds
\ *** Changes 05-25-05 adding sensing of audio feedback from FM radio in PLL loop to sync to a delayed broadcast signal