> changing only the processor type

> pin 8 to one side of an LED and from the other side

James, welcome

Pin 8 (RB2) on the 628 might not be RB2 on the original processor. So
the s/w could be flashing a pin but you haven't got the LED in the right
place. Be aware also that the 628 needs cmcon set if you use PortA
pins as general purpose I/O

         movlw   b'00000111'  ;disable comparators
         movwf   cmcon

> I removed this from an old CDROM and there is no flat side or longer
> lead)

Hold it up to the light - the smaller electrode inside is the anode, ie that
lead goes to positive

You should be abe to scavenge crystals and ceroscs from old PCBs
like CD drives, modems, LAN cards etc

> 1) I have not tied any of the other pins to anything

You can set them all to outputs without connecting them to anything

> Can I tie them all (selected pins?) to a resister and then that to the
> negative rail or do I > need enough resistors for every unused pin?

If you have to, not "a" resistor for all pins, one each. That's if they are
inputs with usually no input (for example open switches that connect
to Vss on closure need a pull-up)

> 2) The power supply is an old Motorola cell phone wall wart charger.
> It gives me about 4.6V @ up to 1.5 A but I have not put any caps
> anywhere.

Shouldn't make a big difference to this if the quality of the DC output
is reasonable. See if you can measure any AC on it. You'll lose some
voltage but you could rectify the voltage anyway

PSU +ve ---- diode > ----- capacitor +ve = PIC supply

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