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

The Intel i960 was a remarkable 32-bit processor of the 1990s with a confusing set of versions. Although it is now mostly forgotten (outside the many people who used it as an embedded processor), it has a complex history. It had a shot at being Intel’s flagship processor until x86 overshadowed it. Later, it was the world’s best-selling RISC processor. One variant was a 33-bit processor with a decidedly non-RISC object-oriented instruction set; it became a military standard and was used in the F-22 fighter plane. Another version powered Intel’s short-lived Unix servers. In this blog post, I’ll take a look at the history of the i960, explain its different variants, and examine silicon dies. This chip has a lot of mythology and confusion (especially on Wikipedia), so I’ll try to clear things up.

source: HN

Barbara Blackburn is often cited as the fastest typist in history. She even appears in the Guinness Book of World Records! She must be legit right? Well, maybe not. I was supposed to make a video about the new typing speed world record, and instead got pulled into a Barbara Blackburn rabbit hole that I can’t seem to escape. TL;DR She’s not that fast.

The purpose of the <keygen/> element was to allow a web browser to generate a private/public keypair upon submitting a form, in a way that allowed a web browser to be enrolled in a new client certificate.

source: L

The bottom line is, as we’ll demonstrate in the next few screenshots, this laptop isn’t just a MIPS laptop: it’s three apparently completely independent RISC systems with their own memory, flash and operating system on an internal Ethernet network. All those NIC and switch chips are the internal communication interfaces from the Au1550 to the IXP425 and the AR2316A, but using the IDE bus lines instead of actual twisted pair. That’s not what I was expecting to find in a Sun Ray!

source: HN

Two boxers. No flicker? How is this possible? The MMC2 Mapper chip: Explained

How to draw too many sprites by making one a background, then how to smoothly animate it by side scrolling.

Determining the airspeed and altitude of a fighter plane is harder than you’d expect. At slower speeds, pressure measurements can give the altitude, air speed, and other “air data”. But as planes approach the speed of sound, complicated equations are needed to accurately compute these values. The Bendix Central Air Data Computer (CADC) solved this problem for military planes such as the F-101 and the F-111 fighters, and the B-58 bomber. This electromechanical marvel was crammed full of 1955 technology: gears, cams, synchros, and magnetic amplifiers. In this blog post I look inside the CADC, describe the calculations it performed, and explain how it performed these calculations mechanically.