Executives who takes a perverse pride in their inability to type have found themselves a bit stymied by the personal computer revolution, which puts a premium on keyboard virtuosity. But Kalman Toth may have a solution for them: a word-processing system that allows users to type the most commonly used words by hitting just four keys.

Toth's Writing Wizard, due out next year, isn't just software. It comes with a special keyboard with 60 function keys, including 40 programmed with common words, which is supposed to cut some typing time right there. The software works this way: A user types the first three letters of a word, then a list appears at the top of the screen showing the most common words that begin with those letters, and the user picks out the one he or she wants by hitting one digit key.

The program's dictionary contains the 2,500 most commonly used business words and phrases, and users can add their own. It is all rather cumbersome if you know how to type, but it could come in handy for folks who want to write "per our conversation" or other stock phrases it the touch of four buttons.

Toth says his Writing Wizard will be available by early 1985 at a cost of about $500, including the extra keyboard and a word processor. He launched his company, Businessoft Inc., in Paramus, N.J., with $600,000 in seed capital and has a pledge for half the $3 million he needs to launch Writing Wizard in the marketplace. In a year or so, Businessoft hopes to make the system partially voice-activated.

Toth says computers should be as easy to use as cars, preferably as easy as vending machines. Keyboards have no place in this scheme. "Can you imagine if you used a typewriter keyboard to drive your car?" he says. "We would have accidents all over the place."