Thanks Mike,
18 ms is a bit too long for my purpose.
So what I'm considering is to connect the Xtal to the TMR1 oscillator terminals and connect the output (T1CK1) to the external clock input OSC1 as shown in Fig 14-2.
This is very easy to do on my PCB as the pins are adjacent. Do you see any flaws in this idea?
Thanks for the ongoing interest.
Len
I thought the timer1 oscillator could only work at low speed (32kHz). Could you use two crystals? A 32k and 20M would provide the best of both worlds but does tie up 4 pins.