How can I get Timer 1 to overflow every 5 seconds

[Acetronics2]

...

The only solution for timer 1 to overflow every 5 sec is to run the CPU clock @ 400 khz ...

Alain

Oh, Oh ...

I had forgotten the 876 timer1 simply could be driven by its own oscillator up to 200 Khz ... ( NOT the CPU Osc @ 20 Mhz !)

so, no problem ... 32768 Hz are easy to find Xtals !

note also exist " Gate driven " Timers on numerous chips ( see 12f 683 i.e)

Alain