Clock Runs Computer In Slow-Motion

July 8, 2023 by Bryan Cockfield 27 Comments

At the heart of all computers is a clock, a dedicated timepiece ensuring that all of the parts of the computer are synchronized and can work together to execute the instructions that the computer receives. Clock speeds for most modern off-the-shelf computers and smartphones operate around a billion cycles per second, and even clocks that tick at a human-dizzying speed of a million times per second have been around since at least the 1970s. But there’s no reason a computer can’t run at a much slower speed, as [Greg] demonstrates in this video where he slows down a 6502 processor to a single clock cycle per second.

To reduce the clock speed from the megahertz range down to a single hertz or single clock cycle per second, [Greg] is using the pendulum from an actual clock. He attaches a small magnet to the bottom of the pendulum which is counted by a sensor as it swings past. Feeding that pulse into a monostable conditioner yields a clock signal which is usable for one of his 6502-based computers, and at this extremely slow rate, it’s possible to see the operation of a lot of the computers’ inner workings a step at a time. In fact, he optimized the computer’s operation as this slow speed let him see some inefficiencies in the program he was running.

It helps if your processor is static, of course. Older CPUs with dynamic storage for registers and some with limited-range PLLs would not work with this technique. The 8080A, for example, required a clock of at least 500 kHz.

Not only can this computer use a pendulum clock as the basis for its internal clock, but [Greg] also rigged up a mechanism to use a heartbeat. Getting in a little bit of exercise to increase his heart rate first will noticeably increase the computer’s speed. And, if you’re looking to get a deeper glimpse into the inner workings of a computer, we’d recommend looking at one which forgoes transistors in favor of relays.

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Retro-Inspired Computer Case Hosts Mechanical Keyboard

June 24, 2023 by Bryan Cockfield 5 Comments

During the time in the 1980s when the personal computer was gaining steam as a household fixture, plenty of models shipped with the keyboard built in to the machine itself. This helped reduce costs, lower the physical footprint of the device, and arguably improved aesthetics. But as technology progressed, this type of design fell by the wayside as computers became more modular and configurable. That’s not to say there aren’t any benefits to building a computer like this, though. [jit] is here to show off this Amiga-inspired computer with its own modern built-in mechanical keyboard.

Like the Raspberry Pi 400 which is built into its own case, modern computers like this are extremely portable, relatively simple, and space-efficient. But [jit] did not like the uninspired design of the Pi so he was looking to make some improvements. Starting with the keyboard, it boasts a 60% size board with mechanical keys which are backlit by LEDs. Inside the machine is a Odroid XU4 which has a little bit more power (and is often easier to find) than a comparable Raspberry Pi. The case is 3D printed and includes ventilation and support for the addition of various cooling fans, I/O ports, status LEDs, and switches for the computer inside.

Additionally, some modification of the Odroid itself was needed in order to move the various switches to the case, and the build also includes a somewhat customized power supply internally as well. It’s a well-rounded build that captures the spirit of the old computer cases, but takes advantage of a lot of modern technology at the same time. If you want to go all-out with a build like this, though, take a look at this retro-inspired case (with keyboard included) that manages to get most of a Framework laptop inside.

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Ecological System Dynamics For Computing

June 23, 2023 by Navarre Bartz 3 Comments

Some of you may remember that the ship’s computer on Star Trek: Voyager contained bioneural gel packs. Researchers have taken us one step closer to a biocomputing future with a study on the potential of ecological systems for computing.

Neural networks are a big deal in the world of machine learning, and it turns out that ecological dynamics exhibit many of the same properties. Reservoir Computing (RC) is a special type of Recurrent Neural Network (RNN) that feeds inputs into a fixed-dynamics reservoir black box with training only occurring on the outputs, drastically reducing the computational requirements of the system. With some research now embodying these reservoirs into physical objects like robot arms, the researchers wanted to see if biological systems could be used as computing resources.

Using both simulated and real bacterial populations (Tetrahymena thermophila) to respond to temperature stimuli, the researchers showed that ecological system dynamics has the “necessary conditions for computing (e.g. synchronized dynamics in response to the same input sequences) and can make near-future predictions of empirical time series.” Performance is currently lower than other forms of RC, but the researchers believe this will open up an exciting new area of research.

If you’re interested in some other experiments in biocomputing, checkout these RNA-based logic gates, this DNA-based calculator, or this fourteen-legged state machine.

Marvin Minsky’s 2500 Logo Computer

June 18, 2023 by Dave Rowntree 7 Comments

[Prof. Marvin Minsky] is a very well-known figure in the field of computing, having co-founded the MIT AI lab, published extensively on AI and computational intelligence, and, let’s not forget, inventing the confocal microscope and, of course, the useless machine. But did you know he also was a co-developer of the first Logo “turtle,” and developed a computer intended to run Logo applications in an educational environment? After dredging some PDP-10 tapes owned by the MIT Media Lab, the original schematics for his machine, the Turtle Terminal TT2500 (a reference to the target price of $2500, in 1970 terms), are now available for you to examine.

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A Simple Guide To Bit Banged I2C On The 6502

June 18, 2023 by Dave Rowntree 5 Comments

We covered [Anders Nielsen]’s 65duino project a short while ago, and now he’s back with an update video showing some more details of bit-banging I²C using plain old 6502 assembly language.

Obviously, with such a simple system, there is no dedicated I²C interface hardware, so the programmer must take care of all the details of the I²C protocol in software, bit-banging it out to the peripheral and reading back the response one bit at a time.

The first detail to concern us will be the I²C addresses of the devices being connected to the bus and how low-level bit manipulation is used to turn the 7-bit I²C address into the byte being bit-banged. As [Anders] shows, setting a bit is simply a logical-OR operation, and resetting a bit is a simple logical-AND operation using the inversion (or one’s complement) bit to reset to form a bitmask. As many will already know, this process is necessary to code for a read or a write I²C operation. A further detail is that I²C uses an open-collector connection scheme, which means that no device on the bus may drive the bus to logical high; instead, they must release the drive by going to the high impedance state, and an external pull-up resistor will pull the bus high. The 6532 RIOT chip (used for I/O on the 65unio) does not have tristate control but instead uses a data direction register (DDR) to allow a pin to be an input. This will do the job just fine, albeit with slightly odd-looking code, until you know what’s going on.

From there, it’s a straightforward matter to write subroutines that generate the I²C start, stop, and NACK conditions that are required to write to the SSD1306-based OLED to get it to do something we can observe. From these basic roots, through higher-level subroutines, a complete OLED library in assembly can be constructed. We shall sit tight and await where [Anders] goes next with this!

We see I²C-connected things all the time, like this neat ATtiny85-based I²C peripheral, and whilst we’re talking about the SSD1306 OLED display controller, here’s a hack that shows just how much you can push your luck with the I²C spec and get some crazy frame rates.

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Intel To Ship Quantum Chip

June 17, 2023 by Al Williams 29 Comments

In a world of 32-bit and 64-bit processors, it might surprise you to learn that Intel is releasing a 12-bit chip. Oh, wait, we mean 12-qubit. That makes more sense. Code named Tunnel Falls, the chip uses tiny silicon spin quantum bits, which Intel says are more advantageous than other schemes for encoding qubits. There’s a video about the device below.

It is a “research chip” and will be available to universities that might not be able to produce their own hardware. You probably aren’t going to find them listed on your favorite online reseller. Besides, the chip isn’t going to be usable on a breadboard. It is still going to take a lot of support to get it running.

Intel claims the silicon qubit technology is a million times smaller than other qubit types. The size is on the order of a device transistor — 50 nanometers square — simplifying things and allowing denser devices. In silicon spin qubits, information resides in the up or down spin of a single electron.

Of course, even Intel isn’t suggesting that 12 qubits are enough for a game-changing quantum computer, but you do have to start somewhere. This chip may enable more researchers to test the technology and will undoubtedly help Intel accelerate its research to the next step.

There is a lot of talk that silicon is the way to go for scalable quantum computing. It makes you wonder if there’s anything silicon can’t do? You can access today’s limited quantum computers in the proverbial cloud.

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Your IPhone Can’t Do What This WinCE Device Can!

June 16, 2023 by Jenny List 44 Comments

Most of us probably now have a smartphone, an extremely capable pocket computer — even if sometimes its abilities are disguised a little by its manufacturer. There are many contenders to the crown of first smartphone, but in that discussion it’s often forgotten that the first generally available such devices weren’t phones at all, but PDAs, or Personal Digital Assistants. The fancier ones blurred the line between PDA and laptop and were the forerunner devices to netbooks, and it’s one of these that [Remy] is putting through its paces. He makes the bold claim that it can do things the iPhone can’t, and while the two devices are in no way comparable he’s right on one point. His HP Journada 720 can host a development environment, while the iPhone can’t.

The HP was something of a turn-of-the-millennium object of desire, being a palmtop computer with a half-decent keyboard a 640×240 pixel TFT display, and 32 MB of RAM alongside its 206 MHz Intel StrongARM CPU. Its Windows CE OS wasn’t quite the desktop Windows of the day, but it was close enough to be appealing for the ’90s exec who had everything. Astoundingly it has more than one Linux distro that can run on it with some level of modernity, which is where he’s able to make the claim about the iPhone being inferior.

We remember the Journada clamshell series from back in the day, though by our recollection the battery life would plummet if any attempt was made to use the PCMCIA slot. It was only one of several similar platforms offering a mini-laptop experience, and we feel it’s sad that there are so few similar machines today. Perhaps we’ll keep an eye out for one and relive the ’90s ourselves.