Day 12: Retrocomputing Advent Calendar – Cromemco Z-1 #retrocomputing #firstcomputer #electronics

Day 12: Retrocomputing Advent Calendar - Cromemco Z-1 #retrocomputing #firstcomputer #electronics

A different one today! Cromemco was founded in 1974 by Stanford Ph.D. students Harry Garland and Roger Melen to develop a series of peripherals for early microcomputers, such as the Cyclops digital camera and the Dazzler color graphics interface. In 1976, they came out with their first full microcomputer, the Z-1, which used the same chassis as the IMSAI 8080 but fitted with a 4 MHz Zilog Z80 processor instead of the Intel 8080.

Day 12: Retrocomputing Advent Calendar - Cromemco Z-1 #retrocomputing #firstcomputer #electronics

The Z-1 was very flexible for the time, with 8 KB of static RAM and 22 S-100 bus expansion slots. This allowed the computer to immediately function upon power-up, without manually loading a boot program. Cromemco’s vibe from what I could read was a commitment quality and reliable system, its systems found wide acceptance, and by 1986, more than 80% of major-market U.S. television stations were using the system for news and weather graphics. The company continued to keep going until it was acquired by Dynatech Corporation in 1987.

Day 12: Retrocomputing Advent Calendar - Cromemco Z-1 #retrocomputing #firstcomputer #electronics

Adafruit team member Franklin’s story …

After reading Byte magazine and Jerry Pournelle’s Chaos Manor articles I bought a Cromemco motherboard, (Cromemco named for CROthers MEMorial Hall – the Stanford residence where the founders lived, came into existance in the mid 1970s, and grew to become a major player in the S-100 business systems market.) Cromemco began by making S-100 boards. Their first system called the Z-1 was based on an IMSAI chassis with Cromemco boards, however they quickly moved on to building their own complete systems. I hand soldered the S-100 daughter boards and placed them in a TEI case but had no way to program it. Jerry wrote about Tony Pietch who was in Cal Tech close to me so I looked him up and contacted him. He agreed to burn ROMs for XMON and, with XMON and Tarbell Basic I had a working computer. That was sometime in the late 70’s.

Day 12: Retrocomputing Advent Calendar - Cromemco Z-1 #retrocomputing #firstcomputer #electronics

So of course I needed to find out more about Jerry Pournelle and Chaos Manor! One of the first bloggers!

Pournelle’s journalism focused primarily on the computer industry, astronomy, and space exploration. From the 1970s until the early 1990s, he contributed to the computer magazine Byte, writing from the viewpoint of an intelligent user, with the oft-cited credo, “We do this stuff so you won’t have to.”He created one of the first blogs, entitled “Chaos Manor”, which included commentary about politics, computer technology, space technology, and science fiction.

Have first computer memories? Post’em up in the comments, or post yours on socialz’ and tag them #firstcomputer #retrocomputing – See you back here tomorrow!


Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards

Happy New Year 2025
Happy New Year from Adafruit!

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 38,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — New Products 11/15/2024 Featuring Adafruit bq25185 USB / DC / Solar Charger with 3.3V Buck Board! (Video)

Python for Microcontrollers – Adafruit Daily — Python on Microcontrollers Newsletter: Open Hardware is In, New CircuitPython and Pi 5 16GB, and much more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

EYE on NPI – Adafruit Daily — EYE on NPI Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

Adafruit IoT Monthly — The 2024 Recap Issue!

Maker Business – Adafruit Daily — Same-day delivery, not for convenience, but customer loyalty

Electronics – Adafruit Daily — Level Conversion Hack

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


No Comments

No comments yet.

Sorry, the comment form is closed at this time.