An 8-Bit Transport Triggered Architecture CPU In TTL

When we are introduced to the internals of a microprocessor, it is most likely that we will be shown something like one of the first generation of 8-bit CPUs from the 1970s. There will be the familiar group of registers and counters, an arithmetic and logic unit (ALU), and an instruction decoder with associated control logic. A complex instruction set causes the decoder to marshal registers and ALU to perform all the various functions in the right order. CPUs may have moved on in many ways since the 1970s, but the block diagram of an 8080 or similar still provides a basic grounding for the beginner.

So when we tell you about another home-made CPU using TTL logic chips, you might expect it to follow this well-worn path. Fortunately though the hardware hacking community is always capable of springing surprises upon us, and [Szoftveres] has done just that with his design. It’s a one-instruction-set machine following a transport triggered architecture, and that means it deviates sharply from the conventional architecture described above. Each instruction is a move between the different physical functions of the processor, and computation is achieved by the physical functions working on the data as it is moved into them and presenting the result on their outputs ready to be moved elsewhere. The result is a computer that is in its own way beautifully simple, though at the expense of some inflexibility and lack of some hardware functions we take for granted in more conventional processors.

This machine has been built on a piece of stripboard, and has an accompanying board with display, keypad, and a modem. There is a small board based upon an ATmega8 microcontroller which performs the function of fast program loading, and can be removed once the code is loaded. Software can be written in a C-like language anc compiled using the compiler in his GitHub repository, and he has produced a YouTube video of the machine in operation. This project is well worth reading through in-depth, for its introduction to this slightly unusual architecture.

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Prisoners Build DIY Computers And Hack Prison Network

The Internet is everywhere. The latest anecdotal evidence of this is a story of prison inmates that build their own computer and connected it to the internet. Back in 2015, prisoners at the Marion Correctional Institution in Ohio built two computers from discarded parts which they transported 1,100 feet through prison grounds (even passing a security checkpoint) before hiding them in the ceiling of a training room. The information has just been made public after the release of the Inspector General’s report (PDF). This report is fascinating and worth your time to read.

This Ethernet router was located in a training room in the prison. Physical access is everything in computer security.

Prisoners managed to access the Ohio Department of Rehabilitation and Corrections network using login credentials of a retired prison employee who is currently working as a contract employee. The inmates plotted to steal the identity of another inmate and file tax returns under their name. They also gained access to internal records of other prisoners and checked out websites on how to manufacture drugs and DIY weapons, before prison officers were able to find the hidden computers. From the report:

The ODAS OIT analysis also revealed that malicious activity had been occurring within the ODRC inmate network. ODAS OIT reported, “…inmates appeared to have been conducting attacks against the ODRC network using proxy machines that were connected to the inmate and department networks.” Additionally, ODAS OIT reported, “It appears the Departmental Offender Tracking System (DOTS) portal was attacked and inmate passes were created. Findings of bitcoin wallets, stripe accounts, bank accounts, and credit card accounts point toward possible identity fraud, along with other possible cyber-crimes.”

The prisoners involved knew what they were doing. From the interview with the inmate it seems the computers were set up as a remote desktop bridge between internal computers they were allowed to use and the wider internet. They would use a computer on the inmate network and use a remote desktop to access the illicit computers. These were running Kali Linux and there’s a list of “malicious tools” found on the machines. It’s pretty much what you’d expect to find on a Kali install but the most amusing one listed in the report is “Hand-Crafted Software”.

This seems crazy, but prisoners have always been coming up with new ideas to get one over on the guards — like building DIY tattoo guns, When you have a lot of time on your hands and little responsibility, crazy ideas don’t seem so crazy after all.

Build Your Own PC — Really

There was a time when building your own computer meant a lot of soldering or wire wrapping. At some point, though, building a PC has come to mean buying a motherboard, a power supply, and just plugging a few wires together. There’s nothing wrong with that, but [Scott Baker] wanted to really build a PC. He put together an Xi 8088, a design from [Sergey] who has many interesting projects on his site. [Scott] did a great build log plus a video, which you can see below.

As the name implies, this isn’t a modern i7 powerhouse. It is a classic 8088 PC with a 16-bit backplane. On the plus side, almost everything is conventional through-hole parts, excepting an optional compact flash socket and part of the VGA card. [Scott] acquired the boards from the Retrobrew forum’s inventory of boards where forum users make PCBs available for projects like this.

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The Improved Luggable PC

There are exactly two types of personal computers available today. If you need a lot of horsepower, a powerful GPU, or a full-power CPU, you’re going to end up with a desktop. If you need something portable, you’re getting a laptop with a wimpy CPU and an underpowered GPU. Historically, there has been a third type of PC, the luggable. The luggable is a desktop PC crammed into a case that makes it slightly more portable than a desktop and a monitor.  You cannot buy a luggable PC case right now. They simply do not exist as a commercial product you can shove your own hardware into. This is a form factor an entire industry forgot.

Now there’s a DIY luggable PC. This project from [Roger] packs a standard ATX motherboard, a full-size GPU, a full-size power supply, and everything else that makes a desktop PC powerful into a case that can be stored in an overhead bin.

[Roger] has been working on this project for a while, and it was featured on Hackaday back when it looked like a RepRap Mendel. There have been some significant improvements over the earlier iterations of this project, including a very, very cool hinge mechanism that allows the display to fold in when the computer isn’t being used. It’s a mechanical wonder that prevents scratches. Neat. The rest of the case is constructed out of 2020 aluminum extrusion, and about a one kilogram spool of filament.

Since this is a portable case, there are a few compromises. There are no 5.25″ bays, no 3.5″ bays, and few 2.5″ bays. M.2 SSDs and USB-powered CD drives exist, so this isn’t a big deal.

This is a truly fantastic case in a form factor you can’t buy anywhere else. If you have a spare monitor and a bit of extrusion sitting around, this is one to build yourself.

PC in a mouse

PC In A Mouse

[Slider2732] got his Orange Pi Zero working with a 3 watt amplifier, wireless keyboard (with built-in mouse), and car reversing monitor. But he needed a case to house it in. He remembered that he used to make parameters for ghost hunting by filling PC mouse cases with all sorts of electronics. So why not put the Orange Pi Zero in a mouse too? Looking through his mouse collection, he picked out an old Logitech optical mouse and went to work.

We like that the Logitech has transparent bottom halves, perfect for proving to anyone who might be skeptical that the PC really is in the mouse. A great enhancement we think would be to make the mouse actually be the mouse too! But there doesn’t seem to be enough room left for that. What’s smaller than a Pi Zero that will also run the armbian Linux distribution, OpenELEC Mediacenter, Kodi and a bunch of games?

He even set up the wireless networking for watching YouTube videos. Check out the build and demo video after the break.

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3D Printed Key-Code Is Plastic Digital Logic

3D printers are great for creating static objects, but if you’re clever, it’s possible to print functional devices. If you’re absolutely brilliant you can go far beyond that, which is the case here. This door handle with a key-code lock does it all with 3D printing using mechanism designs that look like alien technology. This is just one application of a much more interesting mechanical digital logic they’re developing (PDF).

Working from the [Hasso-Plattner-Institut], the research team is focusing on metamaterials as mechanisms in and of themselves. The crux of this lock is a series of bistable springs that — if the correct code is entered — will trigger in series to unlock the door. The project builds on the grid of shearing cells seen in the door handle we featured last year. It happens quickly in the video, but the intricate cascade of the handle unlocking is a treat to witness.

It’s a fascinating show of mechanical design. The common elements of digital electronics are all present: set or unset bits, logic gates, propagation issues, the whole works. But there are added challenges in this system, like the need for special cells that can turn the logic chain by 90 degrees and split the signal into more than one part.

This signal splitting is seen in the upper right (bifurcation) and leads into what is in effect an amplifier. The locking bolt must be moved twice the distance of a normal cell, so a dual-cell input is necessary to offset the loss of force from the incoming smaller cells. Cognitively we understand this, but we’re still trying to gain an intuitive sense of the amplifer mechanism.

One thing’s for sure, the overall concept is far cooler than this admittedly awesome door lock mechanism. The paper is worth your time for a deep dive. It mentions their design editor software. You can play with it online but we don’t think it’s been updated to include the new logic cells yet.

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Another 74XX Series CPU

[Jack Eisenmann] is no stranger to building impressive DIY CPU’s on vast stretches of breadboard. This time [Jack] has done away with the seventeen breadboards he used in his last 8-bit computer and instead has gone a step further and designed a set of generously utilised PCB’s for the CPU. The result is the DUO Enterprise.

The CPU design is based around an 8-bit data bus and a 24-bit address bus. As usual, a minimal yet carefully chosen instruction set allows [Jack] to do all the heavy lifting in software as part of the compiler and operating system he is working on. There is no sign of a display yet, instead the computer communicates via a dumb terminal. We love the aluminum foil for shielding! Check out the video, below, to see what we mean.

Over the years, we have seen many of [Jack]’s other CPU builds featured on Hackaday. One of his first designs was a 4-bit CPU that could play many games on a LED matrix.Later he did a much more impressive 8-bit CPU along with analog video output and an OS ofcourse. It could even play pong. He even built a Single Instruction Set Computer (SISC).

His final goal with DUO Enterprise is to allow anyone to utilise its computing power by submitting programs and calculations. Heads up [Jack], our neural net needs training soon.

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