'Calculates a freerunning timer0 refresh clock
xtal = 3686400 'the PICs main crystal
digits = 4 'the number of digits you want to refresh
minrate = 40 'minimum refresh rate per digit
clock = xtal /4 /256 /digits 'max refresh speed of timer0 clock for x digits
for i=8 to 0 step -1
if (clock /2^i) >= minrate then exit
next i
if i=-1 then print "Oscilator too slow for refresh" :end
print "With the TIMER0 prescaler set for 1/";2^i
print "TIMER0 will overflow ";clock /2^i*digits;" times a second"
print "A ";digits;" digit display will refresh at ";clock /2^i;" hz per digit."