A Keyboard Interface For Your SInclair ZX

August 10, 2019 by Jenny List 11 Comments

The SInclair ZX 8-bit computers of the early 1980s were masterpieces of economy, getting the most out of minimal hardware. The cassette tape interface was a one-bit port, the video was (on the first two models anyway) created by the processor itself rather than a CRT controller, and the keyboard? No fancy keyboard controllers here, just a key matrix and some diodes between a set of address lines and some data lines. The ZX80 and ZX81 were not very fast as a result of their processors being tied up with all this work, but it ensured that their retail price could break the magic £100 barrier in the British market, something of a feat in 1980.

A host of hackers still devote their time to these machines, and among them [Danjovic] has updated that ZX keyboard by producing an interface between that matrix and a PS/2 keyboard. As you might expect it uses a modern microcontroller board, in this case an Arduino Nano but it doesn’t stretch the imagination to think that a USB equipped board might perform the same task. It sits upon the relevant lines, and performs the necessary logical connection between them depending upon the serial input from an attached PS/2 keyboard. The project goes into some detail on PS/2 to ZX mappings, but perhaps of most interest is its explanation of the bus timings involved. The Arduino makes use of the ZX WAIT line to hold the Z80 and ensure that there is enough time for it to perform its task, it would be interesting to note whether or not this has a visible impact on BASIC program timing.

We are more used to seeing ZX keyboards being attached to PCs, rather than this way round.

ZX Spectrum image: Bill Bertram [CC BY-SA 2.5].

A Macro Keyboard In A Micro Package

August 9, 2019 by Erin Pinheiro 9 Comments

Remember back in the early-to-mid 2000s when pretty much every cheap USB keyboard you could find started including an abundance of media keys in its layout? Nowadays, especially if you have a customized or reduced-sized mechanical keyboard, those are nowhere to be seen. Whenever our modern selves need those extra keys, we have to turn to external peripherals, and [Gary’s] Knobo is one that looks like it could’ve come straight out of a fancy retail package.

The Knobo is a small macro keypad with 8 mechanical Cherry-style keys and a clickable rotary encoder knob as its main feature. Each key and knob gesture can be customized to any macro, and with five gestures possible with the knob, that gives you a total of thirteen inputs. On top of that, the build and presentation look so sleek and clean we’d swear this was a product straight off of Teenage Engineering’s money-printing machine.

The actions you can do with those inputs range from simple media controls with a volume knob all the way to shortcuts to make a Photoshop artist’s life easier. Right now you can only reprogram the Knobo’s Arduino-based firmware with an In-Circuit Serial Programmer to change what the inputs do, but [Gary] is currently working on configuration software so that users without any programming knowledge will be able to customize it too.

Knobs are just one of those things that everyone wants to use to control their computers, much like giant red buttons. Alternative input devices can range from accessibility-designed to just downright playful. Whatever the inspiration is for them, it’s always nice to see the creativity of these projects.

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A PDP Laptop, For Various Definitions Of A Laptop

July 13, 2019 by Brian Benchoff 16 Comments

Digital Equipment Corp.’s PDP-11 is one of the most important computers in history. It’s the home of Unix, although that’s arguable, and it’s still being used in every application, from handling nuclear control rods to selling Ed Sheeran tickets on Ticketmaster. As the timeline of PDP-11 machines progressed, the hardware did as well, and by the time the PDP was eclipsed by the VAXxen, there were PDP-11s on a single chip. The Eastern Bloc took notice and produced their own PDP-11 on a chip. This is the 1801-series CPU, and like most soviet electronics from the Cold War, they’re readily available on eBay.

[SHAOS] has an interesting project in mind for this PDP-on-a-chip. It’s a standalone computer built around the Soviet re-implementation of the PDP-11, built into a form factor that could be described as a single board computer.

This project is the outgrowth of [SHAOS]’ project for last year’s Hackaday Prize, the PDPii. This was a computer built around a backplane that replicated the PDP-11 using a KR1801VM2 CPU, the Soviet not-a-clone clone of the PDP-11. This project is basically a PDP-11/03 system, except it was made in this century, and you can put it in any computer case, with bonus points awarded for RGB lighting and liquid cooling.

This year’s project, the PDPjr, eschews standardization to something that is far more unique. This build is more or less a single board computer with a character LCD display and a real keyboard. Think of this as the PDP-11 equivalent of the TRS-80 Model 100, a machine widely regarded as being the first laptop.

There’s still a lot of work to go, but [SHAOS] has written a ‘Hello World’ for this chip, and is getting those words to display on the character LCD. That’s a great first step and we can’t wait to see where this project ends up.

Manufacturing In China Hack Chat

July 8, 2019 by Dan Maloney 5 Comments

Join us on Wednesday 10 July 2019 at noon Pacific for the Manufacturing in China Hack Chat with Jesse Vincent!

It started out where many great stories start: as a procrastination project. Open source developer Jesse Vincent decided that messing around with a new keyboard design was a better thing to spend time on than whatever he was supposed to be doing, and thus Keyboardio was born.

Their heirloom-grade keyboards of solid maple and with sculpted keycaps are unique to the eye and to the touch, but that’s only part of the Keyboardio story. Jesse has moved further down the road of turning a project into a product and a product into a company than most of us have, and he’s got some insights about what it takes. Particularly in climbing the learning curve of off-shore manufacturing, which will be the focus of this Hack Chat. Join us to learn all about the perils, pitfalls, and potential rewards of getting your Next Big Idea manufactured in China.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday July 10 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Tokyo Mechanical Keyboard Meetup Knocks Our Clacks Off

June 5, 2019 by Kerry Scharfglass 7 Comments

Just a few days ago, on the other side of the planet from this author, there was a mechanical keyboard meetup in Tokyo. Fortunately through the magic of the Internet we can all enjoy the impressive collection of devices people brought, and boy were there some interesting specimens. There were certainly the inevitable collections of strange artisan keycaps, unusual handmade switches, and keycap sets only available in one group buy five years ago in Nicaragua. But among the bright colors were some truly unique custom designs the likes of which we haven’t see before. A single source is hard to credit, you could check the hashtag #tokyomk6 on Twitter, or [obra]’s thread of photos, or this great blog post (video walkthroughs and photos included) from [romly].

Speaking of [romly], one of their designs stands out as particularly unusual. There are a few things to note here. One is the very conspicuous surface profile of the (clearly totally custom) keycaps themselves. Instead of flat or cylindrical or spherical, these are round. Round like the outside of a log. If we didn’t know better it might look like the entire thing was sculpted or extruded as a single unit. And just below the deck are the perpendicular thumb clusters. Frankly we aren’t sure how to refer to this design feature. The switches are mounted at right angles facing inward so the user places a thumb inside it in a style reminiscent of the DataHand. It’s quite interesting, and we’d be love to know more about what specific functionality it provides.

Another interesting entrant is this keyboard with unusually staggered switches and hexagonal caps (check out the individual markings!). Very broadly there are two typical keyboard layout styles; the diagonal columns of QWERTY (derived from a typewriter in the 1800’s) or the non slanted columns of an “ortholinear” or matrix style layout. By those metrics this is something like an ortholinear keyboard in that its switches overlap their neighbors by half, but the edge to edge close packed caps imply that it might be something else. We’d be very interested to know how typing on this beast would be!

There were so many more awesome designs present at the meetup that this would never end if we tried to document them all. Take a look through the posts and call out anything else too excellent to go unnoticed!

Thanks [obra] for Tweeting about this so we could discover it.

Building An Ergonomic Keyboard

June 3, 2019 by Jenny List 19 Comments

Despite the passing of several decades since that scene in Star Trek IV, the Voyage Home in which Mr. Scott remarks “A keyboard! How quaint!“, here on earth, they remain a central plank of our user interface experience. A plank is an appropriate metaphor, for the traditional keyboard with its layout derived from typewriters and intended to minimize type bar collisions has remained the same flat and un-ergonomic device for well over a century. If like [Tom Arrell] you suffer from repetitive strain injury to your hands and wrists from using a keyboard then a more ergonomic alternative is a must. His solution was to build his own keyboard in two halves.

He was inspired by a colleague’s Ergodox, but balked at the price. Then he found the Dactyl, an open source 3D printed keyboard in two halves, and resolved to build his own. Unlike the Dactyl, however, he wanted his ‘board to be able to operate as either a linked pair operating as one or a pair of separate keyboards. In went a pair of Sparkfun Pro Micro boards to his slightly modified Dactyl, along with a full complement of Cherry MX Brown switches.

The final product lacks key labels so is not for the faint-hearted. But he persevered with it and after a couple of weeks was able to use it without a crib sheet. It’s a bit higher than its commercial equivalent so it needs some improvised wrist rests, but for the price, he’s not complaining.

This isn’t the first keyboard with two halves we’ve shown you, here’s one from 2017.

Via Hacker News.

Tearing Apart Pulse Transformer Switches

June 3, 2019 by Brian Benchoff 29 Comments

If you like mechanical keyboards, you like switches. Historically, switches were weird, with strange capacitive rubber dome switches in Topre boards, buckling springs in the IBM Model M, and beamsprings in earlier IBM keyboards. This teardown of an HP signal generator has the weirdest keyboard switches ever. They’re being called pulse transformer switches, but they are the strangest, weirdest, and most complicated keyboard switch we’ve ever seen

Mechanically, these keys are mounted on a 1×5 plastic frame with a plunger that presses down on a (brass?) photoetched plate. Mechanically, this is effectively a metal dome keyboard that simply presses a springy bit of metal against a contact on a printed circuit board. That’s the mechanical explanation, the electrical theory of operation is much, much weirder.

Electrically, this keyboard consists of a printed circuit board with two coils underneath each key. The circuit is wired up so two keys are ‘read’ at the same time with a pulse from a multiplexer. This pulse induces a current in the ‘sense’ coil of two individual keys which is sent to a comparator. If both keys are not pressed, the comparator sees a positive and a negative voltage which cancels out, meaning no keys are pressed. If one key is pressed, the metal dome shorts out the transformer underneath the keyboard, meaning only one voltage is seen by the comparator, and that key is registered as being pressed.

This is some crazy keyboard circuitry, and I do not say that lightly. There are ‘acoustic’ keyboards out there which consist of a row of keys striking a metal bar with an acoustic transducer on each end. By measuring the time it takes for the sound of a keypress to reach either end of the metal bar, a keypress can be registered. This is weird and expensive to build, and it’s still simpler than a pulse transformer switch. Check out the video below.

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