Mastering the Microwave With 512 Bytes
Litton knew you wanted it simple
This Litton Auto-Cook microwave was the first microwave oven on the market to take the guesswork out of cooking. It uses dual microprocessors to control the oven and to set the cook times for various recipes.
This is standard today and the original Auto-Cook looks retro, but at the time, a microwave oven that built recipes into its memory appeared futuristic, and it was so easy… all you do is push a button. Here’s why: MTSI made it easy by helping develop the machine.
These print ads from 1981 show Litton home economist Terri Van Valkenburg, who drove us crazy sending recipe changes for many months, which made for a superior product: she cooked 6,000 meals, including 300 meat loafs, to get the perfect recipe times and settings.
We stored these settings in the then-amazing memory of 1K nibbles (4 bits) of code in a TMS1000 microprocessor. That is only 512 Bytes! A second TMS1000 was used to scan the buttons, write to the display, and cycle the microwave power and control the timers and door interlock.
One of the first tasks the author of this post did when employed on the project was to design the emulator for this chip, which ran on a desk-sized T.I. 990 mini-computer. This same chipset was also used in the Casablanca ceiling fan.
You can see the dual microprocessors below, located under the vacuum fluorescent display, just under the blue modification wire. This is the original prototype of the oven which did not yet have the colorful keyboard. It’s just a piece of silkscreened stainless steel.
The Litton Auto-Cook microwave worked like a champ and became the basis for a new generation of microwaves, and the power behind millions of meals.