Retro Gadgets: The 1974 Breadboard Project

August 29, 2023 by Al Williams 36 Comments

It is hard to imagine experimenting with electronics without the ubiquitous solderless breadboard. We are sure you have a few within arm’s reach. The little plastic wonders make it easy to throw together a circuit, try it, and then tear it down again. But, surprisingly, breadboards of that type haven’t always been around, and — for a while — they were also an expensive item. Maybe that’s what motivated [R. G. Cooper] to build Slip-n-Clip — his system for quickly building circuits that he published in a 1974 edition of the magazine Elementary Electronics.

The system isn’t really what you would think of as a breadboard today, but it was effective and certainly cheap to build. The biggest problem? It wasn’t something you’d use with DIP ICs. But in the early 1970s, you might not be building very much with ICs, and the ones you used might be in oddball transistor-like packages. Things were strange in the 70s!

A Brief History of Breadboards

In the very old days, people built radios and such on wooden substrates that were actually bread-cutting boards. That’s where the name came from. It was common to draw a diagram with the physical layout you had in mind, glue it to the board, and use it as a guide for building and troubleshooting. Wood was easy to drill and cut. A nail or a thumbtack would make dandy terminals. Probably the last time we saw that done was about a dozen years ago in Make Magazine. Even then, it was only a novelty — few people still build circuits like this, but you can see how [Colin] did it in the video below.

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Hackaday Links: August 27, 2023

August 27, 2023 by Dan Maloney 26 Comments

We mentioned last week how robotaxi provider Cruise was having a no-good, very bad week, after one of their driverless taxis picked a fight with a semi, and it was revealed that amorous San Franciscans were taking advantage of the privacy afforded by not having a driver in the front seat. It appears that we weren’t the only ones to notice all the bad news, since California’s Department of Motor Vehicles issued an order to the company to cut its robotaxi fleet in half. The regulatory move comes after a recent Cruise collision with a fire truck, which injured a passenger in the taxi. Curiously, the DMV order stipulates that Cruise can only operate 50 vehicles during the day, while allowing 150 vehicles at night. We’d have thought the opposite would make more sense, since driving at night is generally more difficult than during daylight hours. But perhaps the logic is that the streets are less crowded at night, whereas daytime is a more target-rich environment.

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Modern Demo For A Casio PB-700 Pocket Computer Plotter

August 13, 2023 by Chris Lott 9 Comments

[Fred] has a Casio PB-700 pocket calculator / computer, complete with the companion docking station featuring a four-color pen plotter, model FA-10, and a microcassette tape recorder, model CM-1. He really wanted to see what this plotter could do, but there were no demos that he could find. So despite only having one working pen, [Fred] took matters into his own hands and proceeded to make his own.

What if I made a program where I type what I want to draw and the PB-700 just draws it?

[Fred] succeeds, shoehorning several sub-projects into a single convoluted work flow: request an image from the PB-700 and after a long pause the plot emerges. The cute microcassette recorder is too much of a hassle, so he emulates the audio interface on a PC using a utility called casutil that reads and writes .wav files in PB-700 format. Much of his effort is spent figuring out how to request an image from Midjourney without being banned, but eventually comes up with a workable but shaky solution. The last steps are to convert the image into a line drawing, and then wrap up all those X-Y coordinates into a Basic program and send it back down to the PB-700 for plotting.

You can read more details in the PloTTY GitHub repository. There were several of these pocket computers with plotters coming out of Japan in the 1980s. In addition to this Casio, the Radio Shack TRS-80 PC-1 and PC-2 come to mind, which were re-branded versions of the Sharp PC-1211 and PC-1500 models. We wrote about them last year. This author had a PC-2 in 1985 and used it to plot antenna patterns at his desk, bypassing the IT department’s red tape. Have you ever used any of these pocket plotters? If so, let us know in the comments below. Thanks to [Altomare] for send us the tip.

Audio, Not Video Over The LKV373 HDMI Extender

August 2, 2023 by Matthew Carlson 11 Comments

[eta] found herself in a flat with several LKV373 HDMI extenders. Find the corresponding transmitter, plug it into your device, and you’ve got a connection to the TV/sound system, no fussing with wires behind the TV. However, [eta] wanted to get rid of the need to plug in a laptop and start sending packets directly to play music. As her flatmate [dan] had already reverse-engineered the receiver, she tested her prototype against their virtualized receiver, de-ip-hmdi.

The actual sending of images was surprisingly straightforward — just a JPEG sliced into 1024 bytes chunks and sent over. However, early testing showed nothing on the receiver. The end of a frame needed marking by setting the most-significant bit of the chunk number to one. Now de-ip-hdmi showed the image, but the actual hardware would not. With something missing, [eta] returned to Wireshark to scan packets. Noticing some strange packets on port 2067, she analyzed the pattern to reveal it sent another packet just before a new frame and included the frame number. With this tweak, it was still not enough. Ultimately, heartbeat packets sent every second synchronize things, but compared to the noise of the video packets, they were easy to miss. Now [eta] had some functioning video streaming rust code.

In theory, audio for the LKV373 followed the same thought process as video. Two channels of 32-bit big Endian integers at 44,100 hz chunked into 992-byte sections and sent as a packet formed the audio stream. With only 992 bytes, two streams, and 4 bytes per sample, each packet only held 2.812 milliseconds of sound. The first tests resulted in no audio output or distorted crunchy sound. Of course, this was every audio engineer’s worst nightmare: jitter. With a spin loop and an efficient ring buffer, the audio packets were soon slinging across the network reliably.

The code is available on a hosted version of GitLab. It’s a beautiful journey through reverse engineering some obscure but relatively cheap hardware. Along the way, there is nicely annotated Rust code, which makes it all the better.

Retrotechtacular: The Computer Center Of 1973

July 25, 2023 by Al Williams 33 Comments

You might expect Bell Labs would have state-of-the-art computers, and they did. But it is jarring to realize just how little that was in 1973, fifty years ago. If you started work at Bell’s Holmdel Computing Center back then, you might have watched one of the orientation videos below. Your first clue about how far things have come might be the reference to the IBM 370/165, which had “3 million bytes of core, 2 million of which are available for programmer use.” Even our laptops today have at least 8 gigabytes of RAM. There were at least two other smaller IBM 370s, too. Plenty of 029 card punches are visible.

If you were trying to run something between 8:00 AM and 5:30 PM, you had to limit your job run time to three minutes, 4,000 lines of output, and no more than 1,000 cards in and 5,000 cards out. Oh, and don’t use more than 384 kB of that core memory, either. If you fell within those limits, you could hand your card deck over at the express counter and get your results in only five or ten minutes. If you were not in the express line but still rated “premium” service, you could expect to wait a half hour.

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HP1973 Project Highlights Workings Of HP-45 Calculator

July 24, 2023 by Chris Lott 3 Comments

[Sarah K Marr] dabbles in retrocomputing and has a fascination with the Hewlett Packard HP-45 calculator, the second calculator in HP’s series introduced in 1973. Over a year ago, she wrote an HP-45 emulator for use on a terminal, dubbed HP45TERM. Not content with success, she upped the challenge and decided to build an even better emulator with a full-featured GUI written in Python. Oh, and she made it multi-platform as well. The result is the HP1973 project.

[Sarah] thought it would take just a few days, but it grew into a much bigger project, as often happens. We’re glad it did because the results are fantastic. The emulator gives you access not only to the calculator itself but can see everything under the hood. The emulator provides full ROM visibility, hardware registers, and standard debugging operations like single stepping. ROM images are available for the HP-45, the HP-35, and the HP-80. The GUI display is configurable, and there’s a plethora of help and information explaining the calculator’s internals. Pre-built binaries are available for MacOS, Windows, and Python source code (3.10.10+) for all operating systems (you’ll need to `pip install numpy` first). The emulation is faithful to the original calculator, and even the hidden timer function can be accessed.

Check this out if you’re into retro calculators. Our own Al Williams wrote about the history of the HP-35 back in 2018 if you want to learn more. Thanks to [J Peterson] for sending in the tip.

Bringing A Baofeng Into The Cyberpunk 2077 Universe

July 14, 2023 by Dan Maloney 10 Comments

You’ve got to love the aesthetics of dystopian cyberpunk video games, where all the technology looks like it’s cobbled together from cast-off bits of the old world’s remains. Kudos go to those who attempt to recreate these virtual props and bring them into the real world, but our highest praise goes to those who not only make a game-realistic version of a prop, but make it actually work.

Take the Nokota Manufacturing radio from Cyberpunk 2077, for instance. [Taylor] took one look at that and knew it would be the perfect vessel for a Baofeng UV-5R, the dual-band transceiver that amateur radio operators love to hate. The idea is to strip the PCB out of a Baofeng — no worries, the things cost like $25 — and install it in a game-accurate 3D printed case. But this is far from just a case mod, since [Taylor]’s goal is to replace the radio’s original controls with something closer to what’s in the game.

To that end, [Taylor] is spinning up an interface to the stock radio’s keypad using some 7400-series bilateral analog switches. Hooked to the keypad contacts and controlled by a Mini MEGA 2560 microcontroller, the interface is able to send macros that imitate the keypresses necessary to change frequencies and control the radio’s settings, plus display the results on the yellow OLED screen that seems a dead-ringer for the in-game display. The video below shows some early testing of the interface.

While very much still a work in progress, we’ve been following [Taylor]’s project for a week or so and he’s really gaining some ground. We’ve encouraged him to enter this one in the Cyberdeck Challenge we’ve got going on now; it might not have much “deck” going for it, but it sure does have a lot of “cyber.”

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