Computer and auto transmission neccesary?

My truck is setup with out a computer. and i like to keep it that way. Is it possible to do a auto transmission with out the computer?? i know the over drive button gets hooked up and what not, but other than that is it REALLY neccesary?

more info would be better.
but most autos that have a computer, shift the trans also.
usually the trans comp is part of the engine comp. what year/model is your truck

Edited: 3/7/2007 4:49:36 PM by BclassBD

its a 86 b2000 and the transmission i only know came off a 80 somethin b2200.

in fact if i recall there was a single prong harness comin off it, and a 4 prong harness

i looked it over again. there is a single wire harness, a two wire (which is probably the overdrive) and the 4 wire harness. im sure one of them is the reverse lights as well. because on the shifter there is a harness and im sure thats the kill switch