I did a bit of tinkering last night and put some code and a breadboarded test rig together in around an hour. And it works fine - I therefore have a fully commented assembler (.asm) file for a PIC 16F628A if you would like it e-mail me at steve@debsdata.freeserve.co.uk and I will send it to you rather than clutter the forum.

Good luck.

Steve.

 

Charlie,
Here's another thought (attached image), so each output also generates a drive voltage for the LED(s) behind it. Forward 'drive' is blocked by the diode.
Regards,
Geoff