Steve Jobs’ Science Fair Project, at age 13

I just discovered this, at a “garage sale” from the original Apple garage. The SCR (Silicon Controlled Rectifier) is a semiconducting latch that behaves electrically like one NPN transistor + one PNP transistor hooked together in a feedback loop.

At age 12, Jobs cold-called HP co-founder Bill Hewlett from the phone book to ask for spare parts for a “school project”. This is probably that very project, as Jobs’ 10-page type-written report is dated 2/29/68 (five days after his 13th birthday, so he would have been sourcing parts when he was 12).

The outreach led to a summer job working on the HP assembly line testing electronic components (random side note: my summer job at age 17 was exactly the same, testing processors and memory chips at Mostek. Then three summers at HP, where I also saw the generosity and kindness of Bill Hewlett).

Jobs’ project shows an early interest in electronics. Three years later, at age 16, he first met Woz. At 18, from his Atari job application (see post below), he described his interests as “electronics tech or design engineer. digital. from Bay area Hewlett-Packard.” At 21, he co-founded Apple.

Jobs’ project is built on plywood, reminiscent of the wooden Apple-1 case. The center features two test circuits, one "designed to demonstrate the basic principals [sic] and characteristics of the silicon-controlled rectifier" and one "designed to demonstrate how the silicon-controlled rectifier is used in its most widely accepted application; motor speed control, light dimming, etc."; and the right panel featuring a diagram and description of a typical 25-amp silicon-controlled rectifier. A power cord in the rear is connected to the second circuit. In the lower right, a Dymo label reads: "Submitted by Steve Jobs, Cupertino J.H., 8th Grade." Another note reads: "Judges, if you wish to see this operate, please plug in Circuit II and oscilloscope and unplug, please unplug!, after using. The oscilloscope should already be set for two to four stationary cycles, but if necessary, judges, please make proper adjustments."

I love this new peek into the teenage tinkerer. More images below…