Zork Zcode Interpreters Appear Out Of Nowhere

November 21, 2023 by Julian Scheffers 27 Comments

Some of our readers may know about Zork (and 1, 2, 3), the 1977 text adventure originally written for the PDP-10. The game has been public domain for a while now, but recently, the interpreters for several classic 1980s machines have also appeared on the internet.

What’s the difference? Zork is not a PDP-10 executable, it’s actually a virtual machine executable, which is in turn run by an interpreter written for the PDP-10. For example, Java compiles to Java bytecode, which runs on the Java virtual machine (but not directly on any CPU). In the same way, Zork was compiled to “Z-machine” program files, called ZIP (which was of course used in 1990 by the much more well known PKZIP). To date, the compiler, “Zilch” has not been released, but the language specification and ZIP specifications have, which has led some people to write custom ZIP compilers, though with a different input language.

For more on the VM, check out Maya’s Zork retrospective. (And dig the featured art. Subtle!)

Of course, that’s not the only type of interpreter. Some programming languages are interpreted directly from source, like this BASIC hidden in the ESP32’s ROM.

Miniature Hydraulic Jack Is A Scale Marvel

November 19, 2023 by Julian Scheffers 6 Comments

Most hydraulic jacks are big tools that can lift upwards of 1000 kg but [Maker B]’s is quite a bit smaller than average.

The world’s smallest hydraulic jack is a tiny hand-machined model made out of tiny pieces of iron, brass and copper. But here’s the kicker: It’s a real hydraulic jack with real hydraulic fluid! At 1/5th scale, it obviously isn’t as strong as a full-size jack, but it can still easily lift an impressive 24 soda cans! Switching between the lathe and mill, [Maker B] shows how all the parts of the jack are made from stock metal in detail, and even explains in simple terms how a hydraulic jack works in this masterpiece of a video.

Over the years, we’ve seen plenty of tiny objects cranked out from stock pieces of metal — often bolts. But the fact that the end result here is a working tool, puts it into a decidedly less common niche. Of course, given what we’ve seen from [Maker B] in the past, it’s hardly a surprise.
Continue reading “Miniature Hydraulic Jack Is A Scale Marvel” →

The masks with which the Intel 4004 was fabricated

Supersize Your Intel 4004 By Over 10 Times

November 17, 2023 by Julian Scheffers 21 Comments

A PCB covered in discrete transistors with light shining through it — This is quite a bit bigger than the original 12mm² die.

The Intel 4004 was among the first microprocessors and one of the first to use the MOS silicon-gate technology. In the decades long race to build bigger CPUs, it’s been mostly forgotten. Forgotten that is, until [Klaus Scheffler] supersized it over ten-fold!

The project took about 2 years to complete and re-creates it faithfully – all 2,300 transistors included – enough to run software written for the Intel 4004. But the idea for this project isn’t unique and dates all the way back to 2000, so what gives? Turning a bunch of masks for silicon fabrication into a schematic is actually harder than it seems! [Tim McNerney] originally came up with the idea to make a giant 4004 for its “35th anniversary”. [Tim] managed to convince Intel to give him schematics and other drawings and would in return make an exhibit for Intel’s museum. With the schematic straight from [Federico Faggin], software analysis tools from [Lajos Kintli] and [Klaus Scheffler] to actually build the thing, they did what [Federico] did in one year without CAD, but in two with modern tools.

The full story by [Tim] is a lot longer and it’s definitely worth a read.

Increase Your Blinkenlights With This Silicon Wafer Necklace

November 14, 2023 by Julian Scheffers 5 Comments

Necklaces aren’t often very high-tech, mostly because of the abuse they have to go through being worn. This was obviously a problem that needed solving, so [Matt Venn] decided to change that by making a necklace out of ASICs just in time for Supercon.

Although this isn’t the first time [Matt] made such a necklace, he though his previous one was “too hip-hop” and not enough “15 million dollar Nikon Lithography Stepper”. Obviously, this means designing the whole chain, art included, from scratch with the blinkenlights to match. Together with [Pat Deegan] and [Adam Zeloof], the team created a beautiful technopunk necklace with art on every chain link and of course a real silicon wafer with a RISC-V tapeout from 2022 on it.

With [Adam] doing modeling for the chain links, and [Pat] and [Matt] designing the electronics required for the mandatory blinkenlights, and some last-minute soldering and assembling the project was finished just in time for Supercon, where it fit right in with all the other blinkenlights. It even runs on one of the RISC-V cores from the same tapeout as the central wafer!

A Mysterious 6502 Apple 2 Simulator

November 11, 2023 by Julian Scheffers 14 Comments

Nice, visual simulators of CPUs such as the 6502 are usually made much later and with more modern tooling than what they simulate. But what if that wasn’t the case? What if a simulator runs on the very hardware it’s simulating?

This is what [Tea Leaves] stumbled upon when he found a mysterious disk with only “APL6502.SIM” on it. [Tea Leaves] demonstrates the simulator with a basic 6502 assembly program, revealing an animated, beautiful Apple 2 simulator that actually runs on the Apple 2! The simulator shows all the major components of a 6502 and actually animates the complete data flow of an instruction.

But why is this mysterious? It’s mysterious because – a “hello” program aside – it’s the only thing on the disk! Not so much as a single clue as to where it came from. [Tea Leaves] finds out where it comes from, including incorrectly copied disk images and a revelation at the end.

Video after the break.
Continue reading “A Mysterious 6502 Apple 2 Simulator” →

An Intel 8008 On A Single-Board Computer

November 4, 2023 by Julian Scheffers 8 Comments

The last time we covered [Dr. Scott M. Baker], he made his Heathkit H8 run on a considerably older processor than it was made for. This time, apparently still not satisfied with the number of 8008 computers, he made an Intel 8008-based single-board computer.

The Mini-08, as [Scott] calls it, is based on his previous endeavour of downgrading the Heathkit H8. Its “CPU board” has even more memory than its predecessor at 128KiB RAM and ROM and an 8251 UART connected to a DB25 serial port. The entirely optional “display board” adds to that 10 digits of 7-segment displays, a backlit Cherry MX Blue hexadecimal keypad, a real-time clock and even a 4-voice sound generator!

[Scott] has also done an impressive job with the software, porting BASIC, FORTH, a clone of Star Trek and some utilities to his Mini-08. He demonstrates both BASIC and FORTH by printing “SCOTT WAS HERE” in a for loop and finishes off by showing how to use some of the display board with FORTH.

Like last time, he published design files and resources for you to enjoy. Overall, an interesting spin on the retro single-board computer concept.

Video after the break.

Continue reading “An Intel 8008 On A Single-Board Computer” →

Real NES Plays Frame-Perfect For You On Twitch

October 29, 2023 by Julian Scheffers 3 Comments

Have you ever wanted to be the best Super Mario Brothers speedrunner, but you just couldn’t do the frame-perfect inputs? Fear not, because [Gregory Strike] is here to save the day with his automatic NES controller!

In his previous video, [Greg] already made an automatic controller that plays a sequence of inputs at the perfect time, but it still failed some of the frame-perfect tricks. So what gives? Deviation in the timing of the NES itself gives, as he shows how the NES doesn’t sample inputs at exactly the same time every frame. To account for this, he used the latch signal, which starts the controller reading process as a time reference, and replaced his digital “mixtape” with a more time-flexible Arduino. After the modification, he shows it pulling off frame-perfect inputs every time he plays Super Mario Brothers.

But if you have a controller that can do frame-perfect inputs and it can be connected to a computer, you can connect the controller to the internet! That’s right, [Greg] created a Twitch bot that tells the Arduino exactly what inputs to send, which then relays it to the NES. It accepts simple sequences of inputs via chat, and you can try it out right now on [Greg]’s Twitch stream.

This project shows promising results, and we think it’s possible to do much more with its internet connection. We’re certainly looking forward to what [Greg] decides to make next.

Video after the break.
Continue reading “Real NES Plays Frame-Perfect For You On Twitch” →