Episode 173 - Hybrid Programming

Hybrid computers are composed of a digital computer linked to an analog computer. That leads to an interesting challenge: how do you write software for one of these things? The analog side actively resists programming, while the digital side can't comprehend of continuous values. In the 1960s specialized languages appeared that tried to bridge this divide. And, I assure you, they are not at all like what you would expect.

In 1945 the first electronic digital computers sparked to life. Number crunching was instantly changed forever! The perfect technology had arrived, and there was never even a competition, right? Well, not so much. The simple fact is that computers sucked for decades. Digital machines have all kinds of inherent pitfalls. There was another entire lineage of computers that existed in the shadow of digital machines: the analogs. Eventually the two technologies would merge in an attempt to create the truly perfect machine: one with the flexibility and accuracy of a digital computer, and the speed and interactivity of an analog computer. The result were hybrids!  

Last episode I said that Fourth Generation Languages were a topic for another time. Well... this counts as another time. Today we are trying to figure out what exactly makes a language 4th Generation. Along the way we will see why the term bugs me so much, why 4GLs seem so strange, and how a programmer can increase their productivity by 2,000% (some restrictions apply).

I'm back to normal episodes, and I'm running out the gate with a weird one. Thoroughbred/OS was a multi-user and multi-tasking operating system for the IBM PC. It's mian interface was... BASIC of all things! What exactly is this oddity? https://winworldpc.com/product/thoroughbred-os/662 - Try Out Thoroughbred/OS yourself

I recently had the chance to talk to Ben Zotto about his upcoming book: Go Computer Now! - The Story of Sphere Computers. It's all about an obscure machine powered by the Motorola 6800 that released in 1975. I figured it was the perfect faire for my audience. And... I really want to read this book! You can back the project over at kickstarter: http://kickstarter.com/projects/bzotto/go-computer-now-the-story-of-sphere?ref=ey52pt And find out more at Ben's sites: https://gocomputernow.com/, https://sphere.computer/

In 1981 Joe Dellinger attempted to create the perfect computer program: a virus that spread silently. In 1982 a revision of that virus broke containment. It would have remained completely hidden if it wasn't for an obscure Apple II game. Today we look at the story and motivation behind that virus, and how it slipped into the sands of time. Or... did it!? The truth is if you have an Apple II it may be infected with Dellinger's virus! My main source: https://virus.wdfiles.com/local--files/applvir/Applvir.txt  

Imagine a secret number that could be used to bring your computer to a screeching halt. In 1977 Gerry Wheeler discovered an interesting feature of Motorola's new 6800 microprocessor. There was a secret instruction that, if read, would cause the processor to stop working. He called this magic number Halt and Catch Fire, or HCF, and wrote a neat article about the operation. This was the first time the public would learn about the secret powers of HCF, but this isn't actually the beginning of the story. When it comes to HCF things are more complicated than that... but only a little bit!

Have you ever had a computer do something you can't explain? Have you ever thought a machine had a mind of its own? In 1971 Met Life was faced with this exact conundrum. Their tape drives, for some reason, were throwing tape all over the floor every night. Systems were checked and no flaws were found, but every morning an operator would walk in on an absolute mess. What could make a healthy machine spit up it's precious tape?  

My trilogy on the PDP-11 concludes with a look at the far flung places this computer can take us. In this episode we look at some issues with claims of the PDP-11's linage, smuggling, Hungarian-made microcode, and much more. Along the way we answer the question: if the PDP-11 was such a good design then where was it during the home computing boom of the 80s?  

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.