In the interest of giving Earl something to get started with he can look at this Philips WEB page http://www.semiconductors.philips.com/products/standard/microcontrollers/download/80c51/index.html. On that page look for a downloadable file called KEYS.ASM. It has some assembler keypad scanning code.

I posted some code a few months ago, in C language, that will scan a keypad for you. It should be relatively easy to read that code and implement an equivalent functionality in 8051 assembler language. To look at that C code click here.

Michael Karas