Two questions:

1
Has anyone measured the accurracy of a 4 or 10 MHz crystal attached to a
16x84 with
the recommended capacitors? Is it enough to make a clock?

2
I have tried to make an accurate delay routine using the tmr0 and
prescaler.
I used mplab to simulate the code but found a jitter of 1 in the amount of
instructions between each interrupt. Is this normal?

regards,
Wouter.