Hi Keith,

Use a baud rate friendly crystal. (0% baud rate error).

18.432 MHz for the 18F452 and 3.6864 MHz for the 16F88s.
Does your compiler support these oscillator frequencies?

Best regards,

Luciano

* * *

Baud rate friendly crystals:

1.8432 MHz
3.6864 MHz
7.3728 MHz
11.0592 MHz
14.7456 MHz
18.4320 MHz