💾🖥️📖 Inside the Personal Computer: An Illustrated Introduction in 3 Dimensions: A Pop-Up Guide. Text by Sharon Gallagher. Paper engineering and design by Ron van der Meer (1984). Posting this and more as we get our #retrocomputing series ready for next month!
🎄💾🗓️ Day 8: Retrocomputing Advent Calendar - Commodore PET 🎄💾🗓️
The Commodore PET (Personal Electronic Transactor) came out in 1977 and was among the earliest personal computers - featuring an all-in-one design with a keyboard, monochrome monitor, and cassette deck - all within a single chassis. Powered by an MOS Technology 6502 microprocessor running at 1 MHz, it had 4 KB of RAM and was expandable up to 96 KB in later models. The PET had Commodore BASIC stored in ROM, allowing users to write and execute programs directly. Its display supported text resolutions of 40×25 or 80×25 characters, using the PETSCII character set for semigraphic capabilities. While early models did not have sound, later versions included a basic beeper. PET's all-in-one design and user-friendly interface contributed to its popularity in education and business, and it sold approximately 219,000 units before its discontinuation in 1982.
Check out the wikipedia page for some extended history and great photos -
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!
🎄💾🗓️ Day 18: Retrocomputing Advent Calendar - Commodore 64🎄💾🗓️
The Commodore 64, released in 1982, is one of the ones we keep hearing got many people their start in their own computing history. Powered by a MOS Technology 6510 processor at 1.02 MHz and featuring 64 KB of RAM, it became the best-selling single computer model of all time, with an estimated 12.5–17 million units sold. Its graphics were driven by the VIC-II chip, capable of 16 colors, hardware sprites, and smooth scrolling, while the SID (Sound Interface Device) chip delivered advanced audio, supporting three voices with waveforms and filters, making it a lot of fun for gaming and music.
Featured a built-in BASIC interpreter, allowing users to write their own programs out-of-the-box. The C64’s affordability, large software library, lots of games, productivity, and educational applications made it a household name. It connected to TVs as monitors and supported peripherals like the 1541 floppy disk drive, datasette, and various joysticks. With over 10,000 commercial software titles and a thriving homebrew scene, the C64 helped define a generation of computer enthusiasts.
Its impact on gaming was gigantic, iconic titles like The Last Ninja, Maniac Mansion, and Impossible Mission. The C64 also inspired a demoscene, where programmers pushed its hardware for visual and audio effects. The Commodore 64 remains a symbol of computing for the masses and creative innovation, still loved by retrocomputing fans today.
Check out the National Museum of American History, and Wikipedia.
https://americanhistory.si.edu/collections/object/nmah_334636
https://en.wikipedia.org/wiki/Commodore_64
And…! An excellent story from Jepler -
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While I started on the VIC 20, the Commodore 64 was my computer for a lot longer. Its SID sound chip was a headline feature, and many of my memories of it center around music. Starting with Ultima III, each game in the series had a different soundtrack for each environment (though each one was on a pretty short loop, it probably drove my folks nuts when I would play for hours). There were music editors floating around, so I tried my hand at arranging music for its 3 independent voices, though I can't say I was any good or that I have any of the music now. You could also download "SID tunes" on the local BBSes, where people with hopefully a bit more skill had arranged everything from classical to Beatles to 80s music.
Folks are still creating cool new music on the Commodore 64. One current creator that I like a great deal is Linus Åkesson. Two videos from 2024 using the Commodore 64 that really impressed me were were a "Making 8-bit Music From Scratch at the Commodore 64 BASIC Prompt", a live coding session (http://www.linusakesson.net/programming/music-from-scratch/index.php) and Bach Forever (http://www.linusakesson.net/scene/bach-forever/index.php) a piece played by Åkesson on two Commodore 64s.
Like so many things, you can also recreate the experience online. Here's the overworld music for Ultima III: https://deepsid.chordian.net/?file=/MUSICIANS/A/Arnold_Kenneth/Ultima_III-Exodus.sid&subtune=1 -- the site has hundreds or thousands of other SIDs available to play right in the browser.
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!
🎄💾🗓️ Day 11: Retrocomputing Advent Calendar - The SEL 840A🎄💾🗓️
Systems Engineering Laboratories (SEL) introduced the SEL 840A in 1965. This is a deep cut folks, buckle in. It was designed as a high-performance, 24-bit general-purpose digital computer, particularly well-suited for scientific and industrial real-time applications.
Notable for using silicon monolithic integrated circuits and a modular architecture. Supported advanced computation with features like concurrent floating-point arithmetic via an optional Extended Arithmetic Unit (EAU), which allowed independent arithmetic processing in single or double precision. With a core memory cycle time of 1.75 microseconds and a capacity of up to 32,768 directly addressable words, the SEL 840A had impressive computational speed and versatility for its time.
Its instruction set covered arithmetic operations, branching, and program control. The computer had fairly robust I/O capabilities, supporting up to 128 input/output units and optional block transfer control for high-speed data movement. SEL 840A had real-time applications, such as data acquisition, industrial automation, and control systems, with features like multi-level priority interrupts and a real-time clock with millisecond resolution.
Software support included a FORTRAN IV compiler, mnemonic assembler, and a library of scientific subroutines, making it accessible for scientific and engineering use. The operator’s console provided immediate access to registers, control functions, and user interaction! Designed to be maintained, its modular design had serviceability you do often not see today, with swing-out circuit pages and accessible test points.
And here's a personal… personal computer history from Adafruit team member, Dan…
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The first computer I used was an SEL-840A, PDF:
I learned Fortran on it in eight grade, in 1970. It was at Oak Ridge National Laboratory, where my parents worked, and was used to take data from cyclotron experiments and perform calculations. I later patched the Fortran compiler on it to take single-quoted strings, like 'HELLO', in Fortran FORMAT statements, instead of having to use Hollerith counts, like 5HHELLO.
In 1971-1972, in high school, I used a PDP-10 (model KA10) timesharing system, run by BOCES LIRICS on Long Island, NY, while we were there for one year on an exchange.
Serial no. 01 175Consisting of CPU with table and control panel, tape control unit, Processor Bays 2 and 3, core memory unit MG10, RH10 data
This is the front panel of the actual computer I used. I worked at the computer center in the summer. I know the fellow in the picture: he was an older high school student at the time.
This DEC PDP-10 KA10 Control Panel was donated by Bruce Maier of Long Island New York. The recently retired Mr. Maier operated this early D
The first "personal" computers I used were Xerox Alto, Xerox Dorado, Xerox Dandelion (Xerox Star 8010), Apple Lisa, and Apple Mac, and an original IBM PC. Later I used DEC VAXstations.
Dan kinda wins the first computer contest if there was one… 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!