Have you tried the piclist ?
Tony Kubek has a PC KeyBoard interface with a F84
I've built this and it works great.
http://www.piclist.org/techref/microchip/picboard.htm

Adam Davis has Fr. Tom McGahee's Keypad Tutorial at
http://ubasics.com/adam/pic/archive.shtml
look for FRKEYPAD.ZIP
This is a great tutorial on building a 4*4 keypad interface
also using a F84. I have also built this project.
Both of these could easily be converted to a PIC16F628.

>I am looking for 4*4 keyboard, but $10 each and need
>lots coding to input characters. some thing likes, phone.
>but PC keyboard, is much better choice?

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http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.