This episode we continue my series on the PDP-11 by examining how DEC adapted to the advent of the microprocessor. Along the way we will see how the PDP-11 inspired new generations of computers, and the surprising connection to early digital hobbyists.

Last weekend I had the chance to talk about the LGP-30 and my emulation project at VCF West in Mountain View, CA. The showrunners will be posting a full video later, but that takes a while to go live. In the meantime, here's the audio I siphoned off the sound board and my slide deck.

View my slides here: https://drive.google.com/file/d/1E9-B3EzxudFWX0yJMevbbIkD2qRbBKWi/view?usp=sharing

View the emulator at: https://lgp30.org

The DEC PDP-11 is one of the most influential minicomputers of all time. Some would even call it the most influential computer of all time. But where exactly did it come from? How was it designed? This episode is the start of a 3 part series that will look at how the PDP-11 was created, adapted to changes, and the strange places it ended up.

In 1949 CSIRAC sprung to life in a lab in Sydney, Australia. It was a very early stored program computer. All machines of the era were unique. But CSIRAC, well, it was very unique indeed.

Selected Sources:

 https://cis.unimelb.edu.au/about/csirac/music/reconstruction - The Music of CSIRAC

https://sci-hub.se/10.1109/MAHC.1984.10014 - Pearcy and Beard on CSIRAC

The first batch of digital computers emerge directly following WWII. The hallmark of this generation is uniqueness: no two computers are the same. However, there is a machine that bucks that trend. The IAS Machine, built in Princeton in the late 1940s, served as the inspiration for at least a dozen later computers. But how similar were these Princeton-class computers? What exactly was so special about the IAS Machine? And how does good 'ol Johnny von Neumann get tied up in all of this?

The Eastern Boarder map fundraiser

Selected Sources:

Bigelow Oral History - https://www.si.edu/media/NMAH/NMAH-AC0196_bige710120.pdf

Prelin IAS Machine Report - https://www.ias.edu/sites/default/files/library/Prelim_Disc_Logical_Design.pdf

Lunar Lander is one of the best loves video games of all time. The game was created in 1969 as an homage to the recent Apollo 11. From there it would only spread. Just about anything that can print text has it's own version of Lunar Lander.

The early history of this game is mixed up with something weird: two nearly identical programming languages. Today we will be using the history of Lunar Lander as a good excuse to look at an obscure tongue called FOCAL. This language is so close to BASIC that direct line-by-line translation is possible. But are the two connected?

In 1982 Intel released the iAPX 286. It's was the first heir to the smash-hit 8086. But the 286 was developed before the IBM PC put an Intel chip on every desk. It's design isn't influence by the PC. Rather, it reaches further into the past. Today we are looking at the strange melding of old technology, new ideas, and compatibility that lead to the 286.

In 1973 the world caught it's first glimpse of INTERCAL. It's a wild and wacky language, somewhere between comedy and cutting satire. But the compiler was never circulated. There would be later implementations, but that original compiler remained lost to time. That is, until now. This episode covers how the original source code was found, and my attempt to get it up and running.

Get the source code for INTERCAL72 here: https://github.com/rottytooth/INTERCAL72/

Read the original INTERCAL manual: https://3e8.org/pub/intercal.pdf

The S1 operating system can do it all! It can run on any computer, read any disk, and execute any software. It can be UNIX compatible, DOS compatible, and so, so much more! But... can S1 ship? Today we are talking about an operating system that sounds too good to be true. Is it another example of vaporware? Or is S1 really the world's most sophisticated operating system?

How do you make a computer act less like a computer? It sounds like some kind of riddle, but in the early 1960s it was an actual problem. As IBM customers transitioned from tabulators to computers they ran into all sorts of practical issues. Programmers became a hot commodity. But how do you find a programmer in 1959? And how can you even afford such a luxury? Wouldn't it be better if you could just use your new computer as a tabulator? Well, with RPG, all that and more was possible.