Advent of Computing

A deep dive into telegraph hardware and why text encoding mattered long before computers. Covers needle, Morse, and printing telegraphs plus the push to automate variable-length codes. Explains Baudot’s 5-bit fixed code, distributor mechanics, and time-division ideas. Looks at Murray’s perforator, CR and LF origins, and how teletypes became early computer terminals.

A look at Gemini’s tiny 59-pound guidance computer and how engineers squeezed powerful capabilities into minimal space. Stories about IBM’s design choices, transistor modules, and magnetic core memory. Explanations of navigation sensors, autopilot reentry, and crew interaction with the Manual Data Insertion Unit. A deep dive into early software practices, MathFlow flowcharts, and rigorous testing and simulation methods.

This concludes my series on the distinctive shape of early home computers. In this episode we finally cover the Sol-20 itself, the first system on the market to be shaped like a wedge. More generally, we try to figure out if the Sol-20 was the progenitor of hundreds of machines that followed, or if the wedge was inevitable. For such a simple question, this has become a surprisingly complicated topic. Selected sources: http://archive.computerhistory.org/resources/access/text/2012/10/102702231-05-01-acc.pdf - Lee Felsenstein, oral history at CHM http://www.leefelsenstein.com/wp-content/uploads/2013/01/I_Designed_the_Sol.pdf - Article about the Sol-20's design process http://www.leefelsenstein.com/wp-content/uploads/2013/02/Felsenstein-Tabloid-BW.pdf - Tom Swift Lives! Like the show? Then why not head over and support me on Patreon. Perks include early access to future episodes, and bonus content: https://www.patreon.com/adventofcomputing

A deep dive into why many 1970s–80s home microcomputers used an inclined wedge case with built‑in keyboards. Traces early hobbyist culture from magazines to the TV Typewriter and the Altair cover story. Follows the birth of Processor Technology, the Tom Swift Terminal ideas, and how the VDM‑1 video card made standalone home computers possible.

Hypertext has really become a core offering of daily life, and defined the face of the Internet for decades. But the links and formatting we know so well only make up part of the story. Today we are looking at FRESS(the File Retrieval and Editing SyStem), a hypertext system developed at Brown University at the tail end of the 60s. What makes FRESS so crucial in the history of hypertext is that it was extensively studied. Multiple experiments were carried out to test if FRESS, and hypertext in general, had a place in classrooms. Some useful sources from this episode: https://sci-hub.do/10.1162%2F109966299751940814 1999 paper on FRESS and hypertext in general by Andres van Dam https://archive.org/details/VanDamFinalReport1976 Final experimental report https://archive.org/details/AndyVanDamHypertextFilm Short film on the FRESS experiment

It's here! My celebratory question and answer episode! Contains ramblings on my checkered past, why computer history is important, and why FOIA is so cool.

COBOL! Just its name can strike terror in the hearts of programmers. This language is old, it follows its own strange syntax, and somehow still runs the world of finance and government. But is COBOL really as bad as it's made out to be? Today we are talking a look at the languages origins and how it's become isolated from early every other programming language in common use. Perhaps most importantly for me, we will see is Grace Hopper should really be blamed for unleashing this beast onto mainframes. Selected Sources: https://archive.org/details/historyofprogram0000hist - History of Programming Languages, contains Sammet's account of CODASYL https://archive.org/details/bitsavers_codasylCOB_6843924/ - COBOL 60 Manual https://sci-hub.do/10.1016/0066-4138%2860%2990042-2 - FLOW-MATIC/MATH-MATIC usage paper

ALOHANET was a wireless networking project started at the University of Hawaii in 1968. Initially, it had relatively little to do with ARPANET. But that relative isolation didn't last for long. As the two networks matured and connected together we start to see the first vision of a modern Internet. That alone is interesting, but what brings this story to the next level is the protocol developed for ALOHANET. Ya see, in this wireless network data delivery wasn't guaranteed. Everyone user shared a single radio channel, and terminals could talk over each other. So how did ALOHANET even function? Selected sources used in this episode: https://archive.org/details/DTIC_AD0707853 - The initial 1970 ALOHANET report https://archive.org/details/jresv86n6p591_A1b/page/n3/mode/2up - Summary paper by Kuo, contains a map of ALOHANET https://sci-hub.do/10.1145/1499949.1499983 - Khan's 1973 PRNET paperhttps://www.eng.hawaii.edu/wp-content/uploads/2020/06/abramson1985-Development-of-the-ALOHANET.pdf - 1985 wrap-up of ALOHANET, by Abramson Like the show? Then why not head over and support me on Patreon. Perks include early access to future episodes, and bonus content: https://www.patreon.com/adventofcomputing

This episode we take a look at the earliest days of computing, and one of the earliest forms of computer memory. Mercury delay lines, originally developed in the early 40s for use in radar, are perhaps one of the strangest technologies I've even encountered. Made primarily from liquid mercury and quartz crystals these devices store digital data as a recirculating acoustic wave. They can only be sequentially accessed. Operations are temperature dependent. And, well, the can also be dangerous to human health. So how did mercury find it's way into some of the first computers? Like the show? Then why not head over and support me on Patreon. Perks include early access to future episodes, and bonus content: https://www.patreon.com/adventofcomputing

Where did educational games come from? According to some, the practice of using games in classrooms started in the early 60s with the appearance of the Sumerian Game. However, the story is more complicated than that. This episode we dive into the Sumerian Game, some of the earliest educational games, and the bizarre legacy of a lost piece of software. Like the show? Then why not head over and support me on Patreon. Perks include early access to future episodes, and bonus content: https://www.patreon.com/adventofcomputing