The p-System comes with an editor. It’s a full-screen editor, with some fairly advanced features for the time, like auto-indent, bookmarks, and cut and paste. It’s modal, which is hardly surprising, considering that modal editors were the latest usability improvement of the age, compared to the line-oriented editors of the previous decade.

Also: https://markbessey.blog/2025/04/30/ucsd-pascal-in-depth-2/

Some features of the p-System were really ahead of their time. And then, there is the filesystem. Whenever you set out to create any software, but especially an operating system, which you intend to be aggressively cross-platform, you inevitably run into conflicts between being sophisticated, and hitting the lowest common denominator.

Also: https://markbessey.blog/2025/05/08/ucsd-pascal-in-depth-3-n/

But the 1970s were a very different time. So let’s talk about the text file format for the USCD p-System. This is not just something that applies to the text editor, incidentally. If you declare a file as “text” type in Pascal, it gets the same formatting applied. The formatting is transparently stripped from the file if you send it to the PRINTER: or CONSOLE: device.

Overview: https://markbessey.blog/ucsd-p-system-info/

Also: https://github.com/mbessey/p-system-tools

source: trivium

If you look in a book on processor design, you’ll find a description of how registers can be created from static memory cells. However, the 386 illustrates that the implementation in a real processor is considerably more complicated. Instead of using one circuit, Intel used six different circuits for the registers in the 386.

In the years leading up to its 7 April 1964 launch, however, the 360 was one of the scariest dramas in American business. It took a nearly fanatical commitment at all levels of IBM to bring forth this remarkable collection of machines and software. While the technological innovations that went into the S/360 were important, how they were created and deployed bordered on disaster. The company experienced what science policy expert Keith Pavitt called “tribal warfare”: people clashing and collaborating in a rapidly growing company with unstable, and in some instances unknown, technologies, as uncertainty and ambiguity dogged all the protagonists.

source: HN

Today’s Tedium highlights ACCESS.bus, the would-be standard that wanted to be USB, but couldn’t stick the landing.

Also called the Inter-Integrated Circuit protocol, it’s used as a low-level way to communicate with peripherals, both in its original form and through its de facto successor, SMBus. Developed in the early 1980s by Philips Semiconductor, I²C may be one of the oldest things still in wide use in most modern computers beyond the x86 instruction set—and it is often key to adding driver support into operating systems.

We have long left ACCESS.bus, our would-be contender for the USB throne, into the dustbin of history, but DDC is still at the root of how both HDMI and DisplayPort communicate with our computers.

Twenty five years ago today, the world breathed a collective sight of relief when nothing particularly interesting happened. Many days begin with not much interesting happening, but January 1st, 2000 was notable for not being the end of the world. I’m of course discussing the infamous Y2K bug. We all know the story: many legacy systems were storing dates with two digits- 80 not 1980, and thus were going to fail dramatically when handling 00- is that 1900 or 2000?

Over the past few weeks, various news outlets have been releasing their “25 years later” commentary, and the consensus leans towards this was no big deal, and totally fine. Nothing bad happened, and we all overreacted. There may have been some minor issues, but we all overreacted back then. So I want to take a moment to go back to the past, and talk about the end of the 90s. Let’s go for it.

The Valve.Computer is an 8 bit computer, with the usual 12 bit address and data buses plus the rather unusual current demand of over 200 Amps. It can play a decent game of PONG using its valve and relay RAM, or run a 32 bit Fibonacci sequence using modern NVRAM. After switch on you have to wait a while for the last thermionic valve to warm up. If you look from the side you see a few start to show a red glow.

After visiting Bletchley Park, it occurred to me that several thermionic valve computers had been rebuilt, and now run in museums, but that no new design of a valve computer had been constructed in over 50 years. The thought of building one seemed ridiculous, but I wondered if a modern design could overcome the issues of size, power and the very real danger of high voltages.

source: HN

For practical purposes, old source files are not text files. They are binary files, and must be preserved without modification. It is not OK to take an old source file and convert it to UTF-8. For one thing, UTF-8 didn’t even exist in the times of MASM 5.10 and Microsoft C 5.1, of course old tools can’t deal with it!

source: L

Today, I’d like to tell you about the Etak Navigator, a truly revolutionary product and the world’s first practical vehicle navigation system.

Back in 1985 you used paper maps to navigate, like this one from a Thomas Brother’s map of Los Angeles: A Thomas Brother’s Map. As you can see, the maps weren’t always pretty. By today’s standards it was also supremely difficult and tedious to find locations and even more difficult to work out how to get there. So, when the Etak Navigator launched, it was like something from the future.

source: HN

Now, by trade I’m a software engineer and a trainee scientist - I’ve never designed a book before. However, I’m no stranger to graphic design, having done a variety of things before now. But a book is a new proposition with different challenges. There was a lot of work ahead. But where to begin?

source: Dfly

It’s one of those anachronisms that is deeply embedded in modern technology. From cloud operator servers to embedded controllers in appliances, there must be uncountable devices that think they are connected to a TTY.

source: Dfly

And yet it’s Asimov who apparently owned the only set of postcards of En L’An 2000, a set of 87 (or so) collectible artist cards that first appeared as inserts in cigar boxes in 1899, right in time for the 1900 World Exhibition in Paris. Translated as “France in the 21st Century,” the cards feature Jean-Marc Côté and other illustrators’ interpretations of the way we’d be living... well, 23 years ago.

https://publicdomainreview.org/collection/a-19th-century-vision-of-the-year-2000/

source: HN

In October 1983, 40 years ago this week, Ken Thompson chose supply chain security as the topic for his Turing award lecture, although the specific term wasn’t used back then. (The field of computer science was still young and small enough that the ACM conference where Ken spoke was the “Annual Conference on Computers.”) Ken’s lecture was later published in Communications of the ACM under the title “Reflections on Trusting Trust.” It is a classic paper, and a short one (3 pages); if you haven’t read it yet, you should. This post will still be here when you get back.

In the lecture, Ken explains in three steps how to modify a C compiler binary to insert a backdoor when compiling the “login” program, leaving no trace in the source code. In this post, we will run the backdoored compiler using Ken’s actual code. But first, a brief summary of the important parts of the lecture.

source: L

The title doesn’t lie, and the answer is mildly cursed but par for the course. Something I didn’t mention is that this applies to almost all consoles released in the entire decade, and in fact a significant number (like the Colecovision) ONLY had RF out; the NES was one of the first consoles to have composite at all. If I could do it all again I’d mention that. I’d also keep my Casio CZ-1000 instead of throwing it away when I was 25.

This showcases a demo of megatextures running on n64 hardware. A “megatexture” for the n64 is really just a normal sized textured by modern standards but with that you can do some prebaked scenes that look like they don’t belong on the n64.

https://github.com/lambertjamesd/n64brew2023

The Book8088 is trying hard to basically be compatible with the original IBM PC, containing some of the same or equivalent chips. It’s natural to want to put it through its paces, and one of the best tests for IBM PC compatibility has to be the 8088MPH demo. If 8088MPH will run we must be operating pretty darn close to the original.

Now, as it turns out, most of the demo does run, albeit in RGBI mode which loses out on all the cool composite artifact color effects. But most notably the famous Kefrens Bars effect does not display - the screen just goes blank. What’s going wrong on the Book8088 vs a real IBM PC 5150?

source: HN

This collection shows technical drawings of the Z1 reconstruction. The Z1 built in 1938 was Konrad Zuse’s first computing machine. It was a mechanical machine and was destroyed during World War II. From 1987 to 1989 Zuse reconstructed the Z1 from his memory.

The Z1 consisted of different functional units, e.g. the input unit, the output unit, the memory units, and the addition unit. Each of this unit was built for a specific purpose and all units were connected. With an interactive and freely movable 3D simulation the functionality of the Z1 adder is demonstrated and explained. You can calculate with it by entering numbers and observe how the adder operates with the processes emphasized by color highlighting. The simulation is based on the original patent plans by Konrad Zuse.

source: Dfly

I have been reading Doom Guy by John Romero. It is an excellent book which I highly recommend. In the ninth chapter, John describes being hit by lightning upon seeing Adaptive Tile Refresh (ATS). That made me realize I never took the time to understand how this crucial piece of tech powers the Commander Keen (CK) series.

At its heart the problem ATS solves is bandwidth. Writing 320x200 nibbles (32 KiB) per frame is too much for the ISA bus. There is no way to maintain a 60Hz framerate while refreshing the whole screen. If we were to run the following code, which simply fills all banks, it would run at 5 frames per seconds.

source: HN

In 1969, Harry amazed everybody with a little electronic gadget he’d built which, using the primitive digital integrated circuits of the time, generated random music, played it through a speaker, and flashed lights on its front panel. It was precisely what people expected computers to do, based upon portrayals in the movies and on television, and yet it could be held in your hand and was, internally, very simple. He explained how it worked, and I immediately knew I had to have one. Digital electronics was in a great state of flux at the time, with each manufacturer launching their own line of integrated circuits, most incompatible with one another, so there was no point in slavishly reproducing Harry’s design. Starting from the concept, I designed my own gadget from scratch, using Signetics Utilogic diode-transistor small scale integration integrated circuits which were popular at the time but shortly thereafter made obsolete by 7400 series transistor-transistor logic (TTL). The architecture was identical to Harry’s device, but I opted for more with-it and less power-hungry light-emitting diodes (LEDs) for the display instead of the incandescent bulbs he used. I built the electronics assembly on a sheet of perforated board using wire-wrap fabrication (some people look down their noses at wire-wrap today, but it was good enough for the Apollo Guidance Computer and almost every mainframe backplane of the 1960s, and my wire-wrapped electronics works perfectly fifty years later.)

Little did I imagine, when designing and building the Mind Grenade hardware in 1969, that fifty years later I’d be emulating it on a computer which ran more than a thousand times faster than the one I used in my day job at the time and, furthermore, was sitting on my own desk. But here we are. Thanks to HTML5 and JavaScript, it is now possible to emulate the hardware Mind Grenade entirely in software that runs within any modern Web browser. Below is an abstracted version of the Mind Grenade front panel. Press the power button at the bottom to get things going. The slider at the left controls the pitch and the slider at the right sets the rate at which the notes play. The check boxes below the lights select any of the 16 possible tunes that can be played.

source: HN

Enter Playdate. I had wanted to build a shmup for years, but for various reasons—primarily bad scoping—the efforts always sputtered out. This little yellow device could provide the constraints needed, with the added bonus of a programming challenge to hit consistently high framerates.

source: L