Using tips from this forum my 16F188 program starts with the following code:

CMCON0=%0000111 'Comparators off. (NOTE: CMCON=7 does not work!)
OSCCON.3=1 'Use internal clock. NOTE: PIC defaults to this, even if not specified!

The device is then programmed with the oscillator configured as INTOSCIO and the MCLR pin function as RESET.

Now 2 questions: First, how do I ensure that the internal clock is 8MHz and not 32KHz? Second, is the usual MCLR pullup resistor still needed, since the datasheet indicates that the 16F688 has an internal one? My circuit starts and runs OK with or without one.