I have had brilliant help from David Barker (Mecanique) and Charles Leo (MElabs) about this problem.

The solution is: In MicroCode Studio, click View - Compile And Program Options, then on the Assembler tab, uncheck the Use MPASM option. It then compiles OK.

Charles advises that MPASMWIN 5.11 has a problem in its header file for the 16F688. This can be fixed by upgrading MPASMWIN.

The link to the MPLAB download is:
http://ww1.microchip.com/downloads/e...Doc/mp761a.zip