> the PIC documentation has lots of tables giving crystal speeds
> and some form of constant (I don't have the book in front of me)
> that gives a baudrate with a bit of error, the errors vary from 0%
> to several percent. How much can I get away with? I'd like to run
> the PIC as fast as possible as it is also going to be controlling a
> VFD and some buttons.

That's a terrible table and I've never liked it

I'd suggest 19.6608 for a 20MHz part and 39.3216MHz for a 40MHz
part (39.3216 is 9.8304 with the *4 multiplier). Using these you'll be
very close to the speed limit of the PIC and have 0% RS232 error

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