#computinghistory

🎄💾🗓️ Day 4: Retrocomputing Advent Calendar - The DEC PDP-11! 🎄💾🗓️

Released by Digital Equipment Corporation in 1970, the PDP-11 was a 16-bit minicomputer known for its orthogonal instruction set, allowing flexible and efficient programming. It introduced a Unibus architecture, which streamlined data communication and helped revolutionize computer design, making hardware design more modular and scalable. The PDP-11 was important in developing operating systems, including the early versions of UNIX. The PDP-11 was the hardware foundation for developing the C programming language and early UNIX systems. It supported multiple operating systems like RT-11, RSX-11, and UNIX, which directly shaped modern OS design principles. With over 600,000 units sold, the PDP-11 is celebrated as one of its era's most versatile and influential "minicomputers".

Check out the wikipedia page for some great history, photos (pictured here), and more -

And here's a story from Adafruit team member, Bill!

The DEC PDP-11 was the one of the first computers I ever programmed. That program was 'written' with a soldering iron.

I was an art student at the time, but spending most of my time in the engineering labs. There was a PDP-11-34 in the automation lab connected to an X-ray spectroscopy machine. Starting up the machine required toggling in a bootstrap loader via the front panel. This was a tedious process. So we ordered a diode-array boot ROM which had enough space to program 32 sixteen bit instructions.

Each instruction in the boot sequence needed to be broken down into binary (very straightforward with the PDP-11 instruction set). For each binary '1', a diode needed to be soldered into the array. The space was left empty for each '0'. 32 sixteen bit instructions was more than sufficient to load a secondary bootstrap from the floppy disk to launch the RT-11 operating system. So now it was possible to boot the system with just the push of a button.

I worked with a number DEC PDP-11/LSI-11 systems over the years. I still keep an LSI-11-23 system around for sentimental reasons.

Commodore 2001 series The Commodore PET is a line of personal computers produced starting in 1977 by Commodore International. A single all-in-one case combines a MOS Technology 6502 microprocessor, Commodore BASIC in read-only memory, keyboard, monochrome monitor, and, in early models, a cassette deck. 

Multitech Accel 900 (1985)

🎄💾🗓️ Day 13: Retrocomputing Advent Calendar -🎄Amiga 500 💾🗓️

The Amiga 500 is considered one of Commodore's most important home computers, introduced in 1987; it was important because of how advanced the features were for the time. It was based on a Motorola 68000 CPU running at 7.16 MHz in NTSC versions and at 7.09 MHz for PAL ones, with the main version of 512 KB RAM expandable up to 9 MB. Its OCS provided respectable graphics performance, going up to 736×567 interlaced, with 32 colors out of 4096. The sound system consisted of four 8-bit PCM channels and could give out stereo at as high as 28 kHz. With the keyboard integrated and a compact design, it was ready for home users, while the multitasking operating system, AmigaOS, differentiated it from the rest. At a price the market could afford and featuring multimedia capabilities, this combination contributed to its popularity as it went on to sell about 2.6 million units worldwide.

Making of the Amiga bouncing ball. https://www.generationamiga.com/2020/04/14/amiga-history-the-story-of-the-boing-ball/

🖥️ 🧸 a new (old) approach for 21st-century kids using computers… chronological order

as our kiddo gets older we are going on a journey with her, focusing on the evolution of computing from where it started, and using each one, in order.

our adventure begins with retrofitting a 1998 littletikes/ibm playset to house the early computers, providing her with a tangible way to interact with these machines. might need to do emulators for some of these, but trying to see if we can get many of these, build/re-build, or borrow -

some of the plans will be to explore the hardware - on how it all worked before computing moved to sealed black rectangles that's mostly used to buy things or pay subscriptions services.

here's the "playlist" so far - have any suggestions?

altair 8800 (1975) apple i (1976) commodore pet (1977) apple ii (1977) atari 400/800 (1979)

commodore vic-20 (1980) ibm pc (1981) commodore 64 (1982) apple macintosh (1984) amiga 500 (1987)

next computer (1990) sun sparcstation 10 (1992) compaq presario 425 (1993) sony vaio pcv (1996) apple imac g3 (1998) dell dimension xps t500 (1999)

this approach also seems like it could be a kid's book - a book for parents to follow along with their kids on the history of computers with how-tos on building, or emulating them. maybe even a "build-a-bear" - style workshops / classes for kids and parents, but for making their first computers together…

more later!

🕹️ this was inspired by andy baio's approach of guiding his son through the chronological history of video games (2014)

🎄💾🗓️ Day 9: Retrocomputing Advent Calendar - The Apple Lisa 🎄💾🗓️

The Apple Lisa, introduced on January 19, 1983, was a pioneering personal computer notable for its graphical user interface (GUI) and mouse input, a big departure from text-based command-line interfaces. Featured a Motorola 68000 CPU running at 5 MHz, 1 MB of RAM (expandable to 2 MB), and a 12-inch monochrome display with a resolution of 720×364 pixels. The system initially included dual 5.25-inch "Twiggy" floppy drives, later replaced by a single 3.5-inch Sony floppy drive in the Lisa 2 model. An optional 5 or 10 MB external ProFile hard drive provided more storage.

The Lisa's price of $9,995 (equivalent to approximately $30,600 in 2023) and performance issues held back its commercial success; sales were estimated at about 10,000 units.

It introduced advanced concepts such as memory protection and a document-oriented workflow, which influenced future Apple products and personal computing.

The Lisa's legacy had a huge impact on Apple computers, specifically the Macintosh line, which adopted and refined many of its features. While the Lisa was not exactly a commercial success, its contributions to the evolution of user-friendly computing interfaces are widely recognized in computing history.

These screen pictures come from Adafruit fan Philip " It still boots up from the Twiggy hard drive and runs. It also has a complete Pascal Development System." …"mine is a Lisa 2 with the 3.5” floppy and the 5 MB hard disk. In addition all of the unsold Lisa machines reached an ignominious end."

What end was that? From the Verge -

In September 1989, according to a news article, Apple buried about 2,700 unsold Lisa computers in Logan, Utah at a very closely guarded garbage dump. The Lisa was released in 1983, and it was Apple’s first stab at a truly modern, graphically driven computer: it had a mouse, windows, icons, menus, and other things we’ve all come to expect from “user-friendly” desktops. It had those features a full year before the release of the Macintosh.

Article, and video…

Check out the Apple Lisa page on Wikipedia

, the Computer History's article -

and the National Museum of American History – Behring center -

🎄💾🗓️ Day 3: Retrocomputing Advent Calendar presents the Commodore VIC-20! 🎄💾🗓️

The VIC-20 ⌨️📺🕹️, released in 1980 by Commodore, was the first computer to sell over a million units. It had a 6502 CPU running at 1 MHz, 5 KB of RAM (expandable), and displayed up to 22 characters per line on a color-capable screen. An affordable and friendly computer, the VIC-20 was great at games and basic programming and was supported by a library of software and peripherals. It connected to TVs for display and included Commodore's BASIC interpreter for programming. Its success allowed other computers like the Commodore 64 to make its mark.

And since this is a #firstcomputer celebration here's a fantastic story from Jeff -

My first home computer was the Commodore VIC-20. I must have been in second grade (1986/1987). My Dad was working somewhere away from home, but one weekend Mom drove us two kids to spend the night at the motel that was his home base.

He had bought this computer, the VIC-20, and hooked it up to the hotel TV. I remember entering the program pictured below (probably Mom typed it in, actually) and being blown away by the birds flapping their wings across the screen.

The other distinct memory I have is the next morning my folks woke me up and asked whether I was hungry. No, I very much wanted to play with the VIC-20, so I made up the most obvious word that came to mind: "No, I'm Vic-y". I think they were very puzzled. We probably went and had breakfast regardless of whether we wanted to see the birds flying again.

Check out the wikipedia page for some great history, photos (pictured here), and more -

And the COMMODORE vic-20 commercial commercial compilation, featuring William Shatner.

🎄💾🗓️ Day 15: Retrocomputing Advent Calendar - BBC Micro🎄💾🗓️⌨️🇬🇧

The BBC Micro was an 8-bit microcomputer introduced in 1981 by Acorn Computers under the BBC Computer Literacy Project of the UK, launched with a 6502A processor running at 2 MHz, supported 16 KB to 32 KB of RAM, and featuring a BASIC environment. The machine was versatile, having very good-for-its-time graphics and multi-colors. Expansion capability for educational and experimental use with an assortment of I/O ports, which included a 1 MHz bus, user port, and cassette interface.

The BBC Micro was known for its reliability and emphasis on teaching programming and computer science. The system software, Acorn MOS, was simple and intuitive. With peripherals such as floppy drives and second processors, it performed tasks well beyond its initial use and extended its lifetime by at least a decade or more.

The BBC Micro also pushed forward a lot of gaming and software since this open architecture inspired a thriving community of developers. It also played a big role in the development of the ARM architecture by Acorn Computers, which would change the way modern computers are made in years to come. The BBC Micro has a special place in computing history, which expanded education and brought computing to schools and society through the 1980s.