Parametric search at Microchip.com
13 hits on a 16F PIC in a 28 pin package with an internal oscillator block...
My personal favorite for a 28 pin PIC at the moment wouldn't be a 16F though. It would be a PIC18F2685 (96K of code space) or a PIC18F2550 (USB included)...
All sorts of options here...
Another thing...just to verify it all, get it to at least work, you can use the R/C oscillator. Just hang a resistor and a capacitor off the OSC1 pin and see what happens.
Sure, it's not accurate, but it'll at least verify that your hardware is good.
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