High School Computing - the COSMAC ELF

Sun 27 November 2022

I have been playing with computers since I was 15 or so. It started when I built my own computer as a freshman in high school, the COSMAC ELF. I still have that computer and I wanted to post pictures of it here. I am certain that it does not operate any more, and I am also certain that I could resurrect it - but I like keeping it as it is, as a piece of memorabilia. It's a tangible anchor reminding me of my younger self, and of the beginning of my long interest and career in technology.

Beyond my connection to this particular piece of self-built hardware, I really like the fact that the CDP 1802 microprocessor is historically significant in so many ways. I could quickly dive into minutia that would glaze over the eyes of most of you! But to mention just one point, many early spacecraft used the CDP1802 as their main computer. If you're so inclined, you can find reams more information with a few Google searches.

all the pieces

a closeup

the computer by itself

documentation I used to build it

this manual is from 1977!

back view of the rats-nest wirewrap

closeup of the main components

my scrap-parts power supply

the power supply

all the wiring

full back-side view