Retrofitting An Amstrad CPC6128 With A Floppy Emulator

In the home computer boom of 1980s Britain, you could describe Amstrad as the third-placed home-grown player after Sinclair and Acorn. If you were a computer enthusiast kid rather than a gamer kid, you wanted Acorn’s BBC Micro, your parents bought you Sinclair’s ZX Spectrum because it was cheaper, and you thought the Amstrads were cool because they came with a better monitor than your family’s cast-off 1970s TV.

Amstrad were not a computer company headed by a technical wizard, instead they were a consumer electronics company whose founder [Alan Sugar] had a keen nose for the preferences of the consumer. Thus the Amstrad machines were different from some of their competitors: they were more polished, more appliances than experimental tools. Mass storage devices such as tape decks and floppy drives were built-in, every Amstrad came with its own dedicated monitor, and keyboards were decent quality as you’d see on a “proper” computer.

The high-end Amstrad model was the CPC6128. It came with a 3″ floppy drive, and of most interest, it could run the CP/M operating system. If your parents bought you an Amstrad CPC as a 1980s teen, it wouldn’t have been this one, so they are considerably less common than their 64k brethren with the cassette deck. One has found its way into [Drygol]’s hands though, and because the vintage 3″ floppies are unobtainable nowadays he’s fitted a floppy emulator board that stores data on an SD card.

In a sense, in that this is simply the fitting of an off-the-shelf board to a computer, it’s Not A Hack. But misses the point. This is an unusual home computer from the 8-bit era and his write-up is as much a teardown as it is  a howto. We don’t often get to see inside a 6128.

Fitting the board required the fabrication of a cable, with some very neat soldering work. The board has an LCD display, which is mounted in the floppy opening with a 3D printed bezel. The result is a very usable retro computer, without too much in the way of wanton remodeling.

This is probably the first real Amstrad 6128 we’ve shown you, but that hasn’t stopped enthusiasts making a clone with original chips, and another on an FPGA.


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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Pi Network Attenuators: Impedance Matching For The Strong Of Signal

If you catch a grizzled old radio amateur propping up the bar in the small hours, you will probably receive the gravelly-voiced Wisdom of the Ancients on impedance matching, antenna tuners, and LC networks. Impedance at RF, you will learn, is a Dark Art, for which you need a lifetime of experience to master. And presumably a taste for bourbon and branch water, to preserve the noir aesthetic.

It’s not strictly true, of course, but it is the case that impedance matching at RF with an LC network can be something of a pain. You will calculate and simulate, but you will always find a host of other environmental factors getting in the way when it comes down to achieving a match. Much tweaking of values ensues, and probably a bit of estimating just how bad a particular voltage standing wave ratio (VSWR) can be for your circuit.

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A Robot Arm With The Tender Grip Of An Octopus

If you’ve ever experimented with a robot gripper, you’ll know that while it is easy to make an analogue of the human ability to grip between thumb and forefinger, it is extremely difficult to capture the nuances of grip with the benefit of touch feedback to supply only just enough of the force required to grip and hold an object. You as a human can pick up a delicate eggshell without breaking it using the same hand you might use to pick up a baseball or a cricket ball, but making your robot do the same thing is something of an engineering challenge.

The robot gripper is something that has exercised the minds of the folks at Festo, and the solution they have arrived at is as beautiful as it is novel. They have produced a gripper based upon the action of an octopus tentacle,  though unlike the muscle of the real thing they’ve created a silicone tube which bends inwards when inflated. Its inner surface is covered with octopus-like suckers, some of which can be activated by a vacuum. The result is a very capable and versatile gripper which due to its soft construction is ideal for use in environments in which robots and humans interact.

They’ve put up a slick video showing the device in action, which we’ve put below the break. Tasks such as gripping a rolled-up magazine or a plastic bottle that would tax more conventional grippers are performed faultlessly.

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Hackaday Prize Entry: GoKart Tank

There is probably something in all of us that yearns to drive a tank, just once. Most of us will probably never fulfill it, in fact, unless we work in farming or construction we’re unlikely to even drive a skid-steer vehicle of any type. But that doesn’t mean we can’t have a go at building one ourselves, as [samern] is doing with his Hackaday Prize entry.

The GoKart Tank has a chequered history, as a build that started as an internal combustion go-kart, became a half-track, and eventually the fully tracked electric vehicle we see today. It has a wooden frame, two 1KW electric scooter motors, and tracks made from IntraLox modular plastic industrial conveyor belt parts. This last choice is particularly interesting because even though it isn’t designed for use as a track it is designed for heavy-duty service and could offer a component source for other tracked vehicle projects.

What you see is a working tracked vehicle, but it is not without problems. The electric motors are only powerful enough to move a child, so there are plans to return it to internal combustion power. We can, however, see it working, as you can watch the video of it we’ve put below the break.

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A Smart Switch Board For The ESP8266

With a plethora of IoT projects and inexpensive commercial smart light fittings and mains switches appearing, you might be forgiven for thinking that another offering in this crowded marketplace would be superfluous. But there is always room for improvement in any field, and in this particular one [Xose Pérez] has done just that with his Espurna board.

This board is a very well executed ESP8266 mains relay, with an on-board mains power supply and power monitoring. It was designed with his Espurna (“Spark” in Catalan) custom firmware in mind, which offers support for Alexa, Domoticz, Home Assistant and anything that supports MQTT or HTTP REST APIs.

Best of all, it’s a piece of open source hardware, so you can download everything you need from his GitHub repository to create your own. For the ultimate in convenience you can even order the PCB ready-made from OSH Park.

As a demonstration of the Espurna board in a real application, he’s produced a smart socket project neatly enclosed in a wall-wart style box with an inbuilt Euro style plug and socket.

We’ve featured [Xose]’s work several times before here at Hackaday, he’s something of an IoT wizard. Most recently there was his work with Alexa and the ESP8266, but before that was his MQTT LED array for his laundry monitor.

This Binary Keyboard Is For ASCII Purists

So, you’re a keyboard enthusiast. The ‘board that came from Dell, HP, or whoever made your computer is just not for you. You have an ancient IBM, a decal-free Das Keyboard, or another similarly esoteric text input device. Your typing can be heard three blocks away as the unmistakable clack of bent-spring switches reverberates around you, but you don’t care because you’re in the Zone.

No keyboard can be as high-end as the one you already have, your position in the hierarchy of text entry is assured. But then along comes [Chris Johnston] with his project, and suddenly your desktop looks very cluttered. It’s a binary keypad with only a 0 key, a 1 key, and an OLED display. All input is as a series of binary bytes, so as a hardcore binary typist you’ll need to know your ASCII.

Behind the keys is an Arduino Pro Micro acting in USB HID mode, and running the code you can download from the GitHub link above. It’s a gloriously pointless input device, but we’re sure you’ll agree it has something of the 00110001 00110011 00110011 00110111 about it.

If you think you may have seen this before on Hackaday then you’re not quite right. We have had a binary keypad in the past, but that one had a return key and thus had three keys. This one’s a 2-key ‘board for binary purists.

[via /r/mechanicalkeyboards/]