Custom 40% Model F Keyboard Is 100% Awesome

June 16, 2022 by Kristina Panos 41 Comments

Look closely at this beauty. No, that’s not a chopped IBM Model M or anything — it’s a custom 40% capacitive buckling spring keyboard with an ortholinear layout made by [durken]. Makes it easy to imagine an alternate reality where IBM still exists as IBM and has strong keyboard game, or one where Unicomp are making dreams come true for those who don’t need anywhere near 101 or 104 keys.

Buckling what now? This lovely board uses capacitive buckling spring switches from an old IBM Model F. Basically, every time you press a key, a little spring is bent over (or buckled) in the name of connectivity. In the capacitive version, the spring pushes a hammer onto a pair of plates, causing a change in capacitance that gets recognized as a key press. In this case, those key presses are read by a TH-XWhatsit controller.

Using a Model F XT’s PCB as a guide, [durken] made a field of capacitive pads on one PCB, and made a second, ground plane PCB to avoid interference. In a true homage to these keyboards, [durken] decided to curve the PCB slightly, which naturally complicated almost everything, especially the barrel plate.

The solution was to make a separate barrel plate that slides into the case and gets screwed to the top via mounting bracket. For an extra bit of fun, [durken] mounted an SKCL lock switch under the IBM logo which enables solenoid mode. Be sure to check that out in the (updated!) video after the break.

One of the best things about a buckling spring keyboard is that each key sounds slightly different. Not so in solenoid mode, unless you were to use multiple solenoids.

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Have You Heard Of MCGA?

June 2, 2022 by Jenny List 21 Comments

In the world of PC graphics, the early standards followed the various video cards of the day. There was MDA, familiar through the original text-based DOS prompt, CGA, then EGA, and the non-IBM Hercules along the way. Finally in 1987 IBM produced the VGA, or Video Graphics Array standard for their PS/2 line of computers, which became the bedrock on which all subsequent PC graphics cards, even those with digital outputs, have been built. It’s interesting then to read an account from [Dave Farquhar] of the other now-forgotten video standard that made its debut with the PS/2, MCGA, or Multicolor Graphics Array. This was intended as an entry-level graphics system to compete with the more multimedia-oriented home computers of the day such as the Commodore Amiga and Atari ST.

Offering 320×200 graphics at 256 colors but only two colors at 640×480 it’s difficult to see how it could have been a viable competitor to the Amiga’s 4096-color HAM mode, but it did offer the ability to drive an RGB monitor through its VGA-like socket. The story goes that IBM intended it to provide an upgrade incentive for PS/2 customers to buy a more powerful model with VGA, but in the event a host of third-party VGA-compatible cards emerged and allowed more traditional ISA computers from third parties to retain a competitive edge and eventually sideline the PS/2 line entirely.

We called time on VGA back in 2016, and it’s fair to say that it’s disappeared from PC hardware since then even if much of its technologies still lurk within. It’s pleasing to see though that it remains a stalwart of hacked-together display interfaces, with efforts such as this 7400-based VGA card continuing to impress us.

Striping A Disk Drive The 1970 Way

May 16, 2022 by Al Williams 38 Comments

These days, mass storage for computers is pretty simple. It either uses a rotating disk or else it is solid state. There are a few holdouts using tape, too, but compared to how much there used to be, tape is all but dead. But it wasn’t that long ago that there were many kinds of mass storage. Tapes, disks, drums, punched cards, paper tape, and even stranger things. Perhaps none were quite so strange though as the IBM 2321 Data Cell drive — something IBM internally called MARS.

What is a data cell you might ask? A data cell was a mass storage device from IBM in 1964 that could store about 400 megabytes using magnetic strips that looked something like about a foot of photographic film. The strips resided inside a drum that could rotate. When you needed a record, the drum would rotate the strip you needed to the working part and an automated process would remove the strip in question, wrap it around a read/write head and then put it back when it was done.

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Retrotechtacular: The IBM System/360 Remembered

May 13, 2022 by Al Williams 51 Comments

Before IBM was synonymous with personal computers, they were synonymous with large computers. If you didn’t live it, it was hard to realize just how ubiquitous IBM computers were in most industries. And the flagship of the mainframe world was the IBM System/360. For a whole generation that grew up in the late 1960s and early 1970s, a 360 was probably what you thought of when someone said computer. [Computer History Archive Project] has a loving recollection of the machine with a lot of beautiful footage from places like NASA and IBM itself. You can see the video below.

Not only was the 360 physically imposing, but it had lots of lights, switches, and dials that appealed to the nerdiest of us. The machines were usually loud, too, with a Selectric terminal, card punches and readers, noisy 9-track tape drives, and a line printer or two.

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IBM PCjr Types Again, Thanks To KeybJr

April 24, 2022 by Donald Papp 6 Comments

Most of us think of keyboards — even vintage ones — as being fairly standardized and interchangeable, but that isn’t the case for the IBM PCjr. Its keyboard was quite unlike most others of its time, which means that a PCjr without an original keyboard is pretty much a dust collector. That’s what led [Jozef Bogin] to create the KeybJr, a piece of hardware that allows one to use any AT, XT, or PS/2 keyboard with the IBM PCjr.

The PCjr’s oddball keyboard can be a bit of a hassle for vintage computing enthusiasts.

What was strange about the PCjr’s keyboard? From the outside it looked pretty normal, but it definitely had its own thing going on. For one, the PCjr keyboard operated over a completely different protocol than the other keyboards of the time. In addition, its connection to the host was either by IR, or via its own wired cable adapter.

The KeybJr solves this by using an Arduino-based board to turn inputs from other keyboards of the time into something the PCjr expects. These signals are sent out and received either over infrared, or by the PCjr’s “K” port for a wired keyboard link.

Why bother with the IR functionality? Well, the connector and pins on the PCjr are not very rugged, and sometimes they are damaged. In those cases, it is nice to have the option of using a normal (for the time) keyboard over the IR link. Vintage hardware is not always in perfect shape, after all. That’s why things like ATX power supply adapters for the PCjr exist.

Want to give it a shot? There is a GitHub repository for the KeybJr, and you can see it in action in a brief video, embedded below.

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IBM Eagle Has A Lot Of Qubits

February 8, 2022 by Al Williams 7 Comments

How many qubits do you need in a quantum computer? Plenty, if you want to anything useful. However, today, we have to settle for a lot fewer than we would like. But IBM’s new Eagle has the most of its type of quantum computer: 127-qubits. Naturally, they plan to do even more work, and you can see a preview of “System Two” in the video below.

The 127 qubit number is both impressively large and depressingly small. Each qubit increases the amount of work a conventional computer has to do to simulate the machine by a factor of two. The hope is to one day produce quantum computers that would be impractical to simulate using conventional computers. That’s known as quantum supremacy and while several teams have claimed it, actually achieving it is a subject of debate.

Like any computer, more bits — or qubits — are better than fewer bits, generally speaking. However, it is especially important for modern quantum systems since most practical schemes require redundancy and error correction to be reliable in modern implementations of quantum computer hardware. What’s in the future? IBM claims they will build the Condor processor with over 1,000 qubits using the same 3D packaging technology seen in Eagle. Condor is slated for 2023 and there will be an intermediate chip due in 2022 with 433 qubits.

Scaling anything to a large number usually requires more than just duplicating smaller things. In the case of Eagle and at least one of its predecessors, part of the scaling was to use readout units that can read different qubits. Older processors with just a few qubits would have dedicated readout hardware for each qubit, but that’s untenable once you get hundreds or thousands of qubits.

Qubits aren’t the only measure of a computer’s power, just like a conventional computer with more bits might be less capable than one with fewer bits. You also have to consider the quality of the qubits and how they are connected.

Who’s going to win the race to quantum supremacy? Or has it already been won? We have a feeling if it hasn’t already been done, it won’t be very far in the future. If you think about the state of computers in, say, 1960 and compare it to today, about 60 years later, you have to wonder if that amount of progress will occur in this area, too.

Most of the announcements you hear about quantum computing come from Google, IBM, or Microsoft. But there’s also Honeywell and a few other players. If you want to get ready for the quantum onslaught, maybe start with this tutorial that will run on a simulator, mostly.

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IBM PalmTop Running Modern (Modified) Linux

February 6, 2022 by Bryan Cockfield 19 Comments

The handheld computing market might seem dominated by smartphones today, but before their mass adoption there were other offerings for those who needed some computing power on-the-go. If a 90s laptop was too bulky, there was always the IBM PalmTop which packed punch for its size-to-weight ratio, and for the era it was created in. [Mingcong Bai] still has one of these antiques and decided to see if it was still usable by loading a customized Linux distribution on it.

The PalmTop sported modest hardware even for its time with an Intel 486SL running at 33 MHz with 20 MiB of RAM. This one also makes use of a 1 GB CompactFlash card for storage and while [Mingcong Bai] notes that it is possible to run Windows 95 on it, it’s not a particularly great user experience. A Linux distribution customized for antique hardware, AOSC/Retro, helps solve some of these usability issues. With this it’s possible to boot into a command line and even do some limited text-based web browsing as long as the Ethernet adapter is included.

While the computer is running at its maximum capacity just to boot and perform basic system functions, it’s admirable that an antique computer such as this still works, especially given its small size and limited hardware functionality. If you’re curious about more PalmTop-style computers, take a look at the first one ever produced: the HP-200LX.

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