radio shack

45 Articles

A Deep Dive Into A 1980s Radio Shack Computer Trainer

February 26, 2024 by 17 Comments

For those of us who remember Radio Shack as more than just an overpriced cell phone store, a lot of the nostalgia for the retailer boils down to the brands on offer. Remember the Realistic line of hi-fi and stereo gear? How about Archer brand tools and parts? Patrolman scanners, Micronta test instruments, and don’t forget those amazing Optimus speakers — all had a place in our development as electronics nerds.

But perhaps the most formative brand under the Radio Shack umbrella was Science Fair, with a line of kits and projects that were STEM before STEM was a thing. One product that came along a little too late for our development was the Science Fair Microcomputer Trainer, and judging by [Michael Wessel]’s deep dive into the kit, we really missed the boat. The trainer was similar to the earlier “100-in-1”-style breadboarding kits, with components laid out on a colorful cardboard surface and spring terminals connected to their leads, making it easy to build circuits using jumper wires. The star of the show in the microcomputer trainer was a Texas Instruments TMS1100, which was a pretty advanced chip with a 4-bit CPU with its own ROM and RAM as well as a bunch of IO lines. The trainer also sported a peppy little 400-kHz crystal oscillator clock, a bunch of LEDs, a seven-segment display, a speaker, and a rudimentary keyboard.

The first video below is a general introduction to the trainer and a look at some basic (not BASIC) programs. [Michael] also pulls out the oscilloscope to make some rough measurements of the speed of the TMS1100, which turns out to be doing only about 400 instructions per second. That’s not much, but in the second video we see that it was enough for him to nerd-snipe his collaborator [Jason] into coding up an 80-nibble Tower of Hanoi solver. It’s a little awkward to use, as the program runs in spurts between which the user needs to check memory locations to see which disc to move to which peg, but it works.

It looks like people are rediscovering the Microcomputer Trainer all of a sudden. It might be a good time to pick one up.

Continue reading “A Deep Dive Into A 1980s Radio Shack Computer Trainer” →

Pi Pico Enhances RadioShack Computer Kit

February 20, 2024 by 9 Comments

While most of us now remember Radio Shack as a store that tried to force us to buy batteries and cell phones whenever we went to buy a few transistors and other circuit components, for a time it was an innovative and valuable store for electronics enthusiasts before it began its long demise. Among other electronics and radio parts and kits there were even a few DIY microcomputers, and even though it’s a bit of an antique now a Raspberry Pi Pico is just the thing to modernize this Radio Shack vintage microcomputer kit from the mid 80s.

The microcomputer kit itself is built around the 4-bit Texas Instruments TMS1100, one of the first mass-produced microcontrollers. The kit makes the processor’s functionality more readily available to the user, with a keypad and various switches for programming and a number of status LEDs to monitor its state. The Pi Pico comes into the equation programmed to act as a digital clock with an LED display to drive the antique computer. The Pi then sends a switching pulse through a relay to the microcomputer, which is programmed as a binary counter.

While the microcomputer isn’t going to win any speed or processing power anytime soon, especially with its clock signal coming from a slow relay module, the computer itself is still fulfilling its purpose as an educational tool despite being nearly four decades old. With the slow clock speeds it’s much more intuitive how the computer is stepping through its tasks, and the modern Pi Pico helps it with its tasks quite well. Relays on their own can be a substitute for the entire microcontroller as well, like this computer which has a satisfying mechanical noise when it’s running a program.

Continue reading “Pi Pico Enhances RadioShack Computer Kit” →

Tandy Pocket Computer Assembly Is… Weird

February 12, 2024 by 21 Comments

Radio Shack had a long history of buying things overseas, having their name slapped on them, and selling them in the United States. That was the case with the Tandy Pocket Computers, which were in that awkward space between calculators and full-blown computers. Like many computers of those days, if you wanted to do anything interesting, you needed to turn to assembly language. But as [Old Vintage Computing Research] recalls, the assembly for these little devices was very strange, even for an assembly language. He found out that there is a reason it is so strange and shares it in a deep dive into the device’s machine code history.

The story starts with the Japanese government. In 1969, the ministry in charge of such things decided that it wouldn’t be fair for people who knew a particular computer to have an advantage when taking the Information Technology Engineer exam. So, logically, they made up a fictitious instruction set and architecture for the test. Since no one used it, no one would have an unfair advantage.

However, eventually, Japanese manufacturers started making computers that used the architecture. The architecture was COMP-X, and the assembler was CAP-X. The post covers the history of machines either using the architecture or emulating it going back to the 1970s. It eventually winds up at the Sharp and Casio pocket computers that would wear Radio Shack livery in much of the world, especially the United States.

Continue reading “Tandy Pocket Computer Assembly Is… Weird” →

In Praise Of Old Meters

January 12, 2024 by 54 Comments

We are spoiled with multimeters today. Even the cheapest meter you will get these days is almost surely digital with a tremendous input impedance. But a few decades ago, meters were almost always analog affairs. To make a precise measurement, you needed a mirror under the meter to ensure you read the needle correctly. Moreover, a common meter wouldn’t have that high of an input impedance. If you spent more, you could get a VTVM and, later, one that used FETs to provide high input impedance. [Peter AA2VG] just picked up a vintage Micronta FET volt-ohm meter to join some of the other new and old meters in his shack. You can check it out in the video below.

[Peter] already has a Simpson and a more modern Fluke meter. The Simpson, however, doesn’t have a tube or FET amplifier. The Fluke is nice, but there is something about the needle on an analog meter. If you aren’t old enough to remember, the Micronta brand was a Radio Shack label.

Continue reading “In Praise Of Old Meters” →

Will RadioShack Return?

September 8, 2023 by 145 Comments

We suspect that if you want to write a blockbuster movie or novel, the wrong approach is to go to a studio or publisher and say, “I have this totally new idea that is like nothing you’ve ever seen before…” Even Star Trek was pitched to the network as “Wagon Train to the stars.” People with big money tend to want to bet on things that have succeeded before, which is why so many movies are either remakes or Star Trek XXII: The Search for 4 PM Dinner Specials. Maybe that’s what the El Salvador-based Unicomer Group had in mind when they bought one of our favorite brands, RadioShack. They are reportedly planning a major comeback for the beleaguered brand both online and in the physical world.

In all fairness, the Shack may be better in our memories than in our realities. It was handy to stop off and pick up a coax connector, even if it cost three times the going rate for one. There was a time when RadioShack offered reasonable parts for projects, and it seems like near the end, they tried to hit that target again, but for many years, you could not find the typical parts for a modern project there anyway. However, Unicomer isn’t just a random group of investors.

Continue reading “Will RadioShack Return?” →

DC Zia 30-in-ONE Badge for DEF CON 30

Nostalgic 30-in-ONE Electronics Badge For DEF CON 30

December 9, 2022 by 12 Comments

[hamster] and the DC Zia crew offered up a throwback 30-in-ONE Learn Electronics indie badge for DEF CON 30. The badge is inspired by the Radio Shack “100-in-1” style project kits that so many of us cut our teeth on back in the 70s and 80s.

DC Zia is a hacker group loosely associated with New Mexico who have been working together to make an indie badge for DEF CON each year.  If you aren’t familiar with the badgelife community of hardware hackers and programmers who make electronic indie conference badges, check out our BadgeLife Documentary.

The 30-in-ONE badge is provided in the form of a kit, so the learning and fun begins with assembling the badge. From there, an included booklet guides the badge holder through building and experimenting with 30 different circuits.

The included components include resistors, capacitors, LEDs, transistors, switches, transformer, speaker, OLED display, battery box, and a bundle of jumper wires for making any desired circuit connections.  The documented circuits have compelling titles such as the Electric Cat, Light Theremin, Grandfather Clock, and Frequency Counter.

Flashback to what DC Zia, and other groups, were up to five years prior in our expose on The Hardware Badges of DEF CON 25.

Continue reading “Nostalgic 30-in-ONE Electronics Badge For DEF CON 30” →

Hackaday Links Column Banner

Hackaday Links: July 10, 2022

July 10, 2022 by 9 Comments

We always like to call out a commercial success stemming from projects that got their start on Hackaday.io, and so we’re proud to announce the release of MAKE: Calculus by Joan Horvath and Rich Cameron, a book that takes a decidedly different approach to teaching calculus than traditional courses. Geared to makers and hackers, who generally tend to have a visual style of learning, the book makes heavy use of 3D-printed models to illustrate the relationships between functions. The project started five years ago as a 2017 Hackaday Prize entry, and resulted in a talk at the 2019 Supercon. Their book is now available for preorder, and might be a great way to reacquaint themselves with calc, or perhaps even to learn it for the first time. Continue reading “Hackaday Links: July 10, 2022” →