computer hacks

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computer hacks

Tridora: A Full-Custom CPU Designed For Pascal

October 23, 2024 by 13 Comments

[Sebastian Lederer] has created Tridora: an unusual stack-based CPU core intended for FPGA deployment, co-developed with its own Pascal compiler. The 32-bit word machine is unusual in that it has not one but three stacks, 16-bit instruction words, and a limited ISA, more like those of the 8-bit world. No multiply or divide instructions will be found in this CPU.

The design consists of about 500 lines of Verilog targeting the Digilent Arty-A7 FPGA board, which is based around the Xilinx Artix-7 FPGA line. [Sebastian] plans to support the Nexys A7 board, which boasts a larger FPGA array but has less RAM onboard. The CPU clocks in at 83 MHz with four clock cycles per instruction, so over 20 MIPS, which is not so shabby for a homebrew design. Wrapped around that core are a few simple peripherals, such as the all-important UART, an SD card controller and a VGA display driver. On the software side, the Pascal implementation is created from scratch with quite a few restrictions, but it can compile itself, so that’s a milestone achieved. [Sebastian] also says there is a rudimentary operating system, but at the moment, it’s a little more than a loader that’s bundled with the program image.

The Tridora Gitlab project hosts the Verilog source, an emulator (written in Golang, not Pascal) and a suite of example applications. We see quite a few custom CPUs, often using older or less popular programming languages. Here’s an FPGA-based Forth machine to get you started. Implementing programming languages from scratch is also a surprisingly common hack. Check out this from-scratch compiler for the Pretty Laughable Programming language.

A Modern PC With A Retro OS

October 22, 2024 by 24 Comments

Despite the rise of ARM processors in more and more computers from embedded systems to daily driver PCs, the x86 architecture maintains a stronghold in the computing space that won’t be going away anytime soon. One of the main drivers of this is its beachhead in industrial systems; the x86 architecture is backwards-compatible farther back than many of us have been alive and in situations where machines need to run for years with minimum downtime it’s good to know you can grab any x86 system off the shelf and it’ll largely work. This is also true for gaming, so if you’re like [Yeo Kheng Meng] and want to run games like DOOM natively on modern hardware it’s certainly possible, although there are a few catches.

This build goes into the design of a modern AMD Ryzen 5 desktop computer, with all of the components selected specifically for their use running software more than three decades old now. [Yeo Kheng Meng] is targeting DOS 6.22 as his operating system of choice, meaning that modern EFI motherboards won’t necessarily work. He’s turned to business class products as a solution for many of these issues, as motherboards targeting business and industrial customers often contain more support for antiquated hardware like PS/2 and parallel ports while still having modern amenities like DDR5 memory slots. PS/2 ports additionally are an indicator that the motherboard will supports older non-EFI boot modes (BIOS) and can potentially run DOS natively. Everything here can also run modern operating systems, since he isn’t building this system only to run DOS and retro games.

Beyond the motherboard choice, he’s also using a Soundblaster card for audio which is a design choice generally relegated to history, but still used in modern gaming by a dedicated group. There’s also a floppy drive running via a USB header adapter cable. Of course, there are a few problems running DOS and other era-appropriate software natively on such incomprehensibly fast hardware (by early 90s standards). Some video games were hard coded to the processor clock of the x86 process of the era, so increasing the clock speed orders of magnitude results in several playability issues. In emulators it’s easier to provide an artificially slow clock speed, but on real hardware this isn’t always possible. But [Yeo Kheng Meng] has done a lot to get this modern computer running older software like this. Another take we’ve seen for retro gaming on original hardware is this system which uses a brand-new 486 processor meant for use in industrial settings as well.

DIY Core Rope Memory Z80 Demonstrator Generating A Fibonacci Sequence

October 16, 2024 by 14 Comments

We’ve seen a few retro products using core rope memory, such as telephone autodiallers. Obviously, we’ve covered the Apollo program computers, but we don’t think we’ve seen a complete and functional DIY computer using core rope memory for program storage until now. [P-lab] presents their take on the technology using it to store the program for a Z80-based microprocessor demoboard, built entirely through-hole on a large chunk of veroboard.

For the uninitiated, core rope memory is a simple form of ROM where each core represents a bit in the data word. Each wire represents a single program location. Passing a wire through the core sets the corresponding bit to a logic 1, else 0. These wires are excited with an AC waveform, which is coupled to the cores that host a wire, passing along the signal to a pickup coil. This forms an array of rudimentary transformers. All that is needed is a rectifier/detector to create a stable logic signal to feed onto the data bus.

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Printed Rack Holds Pair Of LattePandas In Style

October 8, 2024 by 25 Comments

ARM single-board computers like the Raspberry Pi are great for some applications — if you need something that’s energy efficient or can fit into a tight space, they’re tough to beat. But sometimes you’re stuck in the middle: you need more computational muscle than the average SBC can bring to the table, but at the same time, a full-size computer isn’t going to work for you.

Luckily, we now have options such as the LattePanda Mu powered by Intel’s quad-core N100 processor. Put a pair of these modules (with their associated carrier boards) on your desktop, and you’ve got considerable number-crunching capabilities in a relatively small package. Thanks to [Jay Doscher] we’ve got a slick 3D printed rack that can keep them secure and cool, complete with the visual flair that we’ve come to expect from his creations.

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The Turing Machine Made Real, In LEGO

October 7, 2024 by 19 Comments

The British mathematician and pioneer of computing Alan Turing published a paper in 1936 which described a Universal Machine, a theoretical model of a computer processor that would later become known as a Turing Machine. Practical computers don’t quite follow the design of a Turing Machine, but if we are prepared to sacrifice its need for an infinitely long paper tape it’s quite possible to build one. This is what [The Bananaman] has done using LEGO as a medium, and if you’d like one for yourself you can even vote for it on the LEGO ideas website.

There’s a video for the project which we’ve placed below, and it goes into quite some detail on the various mechanisms required. Indeed for someone used to physical machinery it’s a better explanation through seeing the various parts than many paper explanations. Not for the first time we’re bowled over by what is possible through the use of the LEGO precision mouldings, this is a machine which would have been difficult and expensive to build in the 1930s by individually machining all its parts.

With just shy of six thousand supporters and a hefty 763 days left at time of writing, there’s plenty of time for it to garner support. But if you want one don’t delay, boost the project by voting for it early.

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Some SPI Flash Chip Nuances Worth Learning

September 29, 2024 by 13 Comments

Some hackers have the skills to help us find noteworthy lessons in even the most basic of repairs. For instance, is your computer failing to boot? Guess what, it could just be a flash chip that’s to blame — and, there’s more you should know about such a failure mode. [Manawyrm] and [tSYS] over at the Kittenlabs blog show us a server motherboard fix involving a SPI flash chip replacement, and tell us every single detail we should know if we ever encounter such a case.

They got some Gigabyte MJ11-EC1 boards for cheap, and indeed, one of the BIOS chips simply failed — they show you how to figure that one out. Lesson one: after flashing a SPI chip, remember to read back the image and compare it to the one you just flashed into it! Now, you might be tempted to take any flash chip as a replacement, after all, many are command-compatible. Indeed, the duo crew harvested a SPI chip from an ESP32 board, the size matched, and surely, that’d suffice.

That’s another factor you should watch out for. Lesson two is to compare the SPI flash commands being used on the two chips you’re working with. In this case, the motherboard would read the BIOS alright and boot just fine, but wasn’t able to save the BIOS settings. Nothing you couldn’t fix by buying the exact chip needed and waiting for it to arrive, of course! SPI flash command sets are fun and worth learning about — after all, they could be the key to hacking your “smart” kettle. Need a 1.8 V level shifter while flashing? Remember, some resistors and a NPN transistor is more than enough.

A series of wooden rectangles are arranged vertically around the edges of a dark wooden base, reminiscent of a very tall radial fan. Light glows from the base up the slots between the vanes. a cord runs from behind the dark base to a small puck of the same color. The setup sits on a light grey table in front of a light grey wall.

A Beautiful Lamp-Inspired PC Case

September 23, 2024 by 5 Comments

Sometimes you see something super cool and think of how it would be really neat if applied in a totally different context. [MXC Builds] saw an awesome lamp from [karacreates], but decided it would be better as a PC case.

We love seeing how different techniques can be used in conjunction to make something that no one method could produce on its own, and for this build, we see [MXC Builds] use 3D printing, laser cutting, CNC, sewing, soldering, and traditional woodworking techniques.

A large part of the video is spent on the CNC process for the walnut base and power button enclosure for the build. As with any project, there are a few places requiring some creative use of the tools on hand, like the walnut piece for the base being too tall for the machine’s usual z-calibration puck or any of [MXC Builds]’s bits to do in one pass, and it’s always interesting to see how other makers solve these issues.

If you’re looking for other beautiful casemods, how about a transparent PS2 or this Art Deco number? Before you go, may we bend your ear about how PC Cases are Still Stuck in the Dark Ages?

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