VCF East 2021: Preserving Heathkit’s 8-Bit Computers

October 27, 2021 by Tom Nardi 39 Comments

To say the Heathkit name is well known among Hackaday readers would be something of an understatement. Their legendary kits launched an untold number of electronics hobbies, and ultimately, plenty of careers. From relatively simple radio receivers to oscilloscopes and televisions, the company offered kits for every skill level from the post-war era all the way up to the 1990s.

So it’s hardly a surprise that in 1977, seeing the success of early home computers like the Altair 8800 and IMSAI 8080, Heathkit decided to join the fray with a computer kit of their own. But by that point the home computing market had started to shift from a hobbyist’s pursuit to something the whole family could enjoy. Compared to the Apple II and TRS-80, both of which also launched in 1977, Heathkit’s machine seemed like the product of a bygone era.

While it might not have gained the notoriety of the microcomputers it was designed to compete with, the Heathkit H8 is certainly not forgotten. Tucked away in a corner at the 2021 Vintage Computer Festival East was an impressive exhibit dedicated to the Society of Eight-Bit Heath Computerists (SEBHC) called Heathkit: Keeping the Legacy Alive. Presented by Glenn Roberts, this collection of original and modern hardware demonstrated the incredible lengths to which this group of passionate Heathkit owners have gone to not just preserve the memory of these often overlooked computers, but to continue to improve upon the kit’s unique design.

Continue reading “VCF East 2021: Preserving Heathkit’s 8-Bit Computers” →

Mechanical Linkage CAD For Everyone

October 21, 2021 by Al Williams 32 Comments

As much as some of us don’t like it, building things for real requires some mechanical component. Maybe it is something as simple as an enclosure or even feet for a PCB, but unless you only write software or play with simulators, you’ll eventually have to build something. It is a slippery slope between drilling holes for a front panel and attempting to build things that move. Sometimes that’s as simple as a hinge and a spring, or maybe it is a full-blown robot articulated arm. That’s why [RectorSquid] built Linkage, a “program that lets you design and edit a two-dimensional mechanism and then simulate the movement of that mechanism” (that quote is from the documentation.

The program has had a few versions and is currently up past 3.15. To get an idea of the program’s capabilities, the first video below shows an older version simulating a ball lift. The second video shows the actual mechanism built from the design. The associated YouTube channel has more recent videos, too, showing a variety of simulations.

Continue reading “Mechanical Linkage CAD For Everyone” →

Retro TV Shows Off Family Memories With Raspberry Pi

September 21, 2021 by Tom Nardi 21 Comments

Fascinated by the look and feel of vintage electronics, [Democracity] decided to turn an old Sony Micro TV into a digital picture frame that would cycle through old family photos in style. You’d think the modern IPS widescreen display would stick out like a sore thumb, but thanks to the clever application of a 1/16″ black acrylic bezel and the original glass still installed in the front panel, the new hardware blends in exceptionally well.

Driving the new display is a Raspberry Pi 4, which might sound overkill, but considering the front-end is being provided by DAKboard through Chromium, we can understand the desire for some extra horsepower and RAM. If it were us we’d probably have gone with a less powerful board and a few Python scripts, and of course there are a few turn-key open source solutions out there, though we’ll admit that this is probably faster and easier to setup.

[Democracity] provides some general information on how he took apart the TV and grafted in the new gear, but of course the exact steps will vary a bit depending on which old TV you end up sending to the big parts bin in the sky. We did like that he made sure to keep all the mechanisms for the buttons and knobs intact, so even if they don’t do anything, you can still fiddle around with them.

Otherwise, his steps for setting up a headless Chromium instance are probably more widely applicable. As are the tips about setting up this particular LCD module and getting the display rotated into the proper orientation. If you just follow along for that part of the guide, you can spin up your own stand-alone Raspberry Pi DAKboard endpoint to take the service for a test drive.

It probably won’t come as much of a surprise to hear that this isn’t the first time [Democracity] has upgraded a piece of vintage hardware. Back in 2017, we covered this gorgeous art deco speaker that he outfitted with RGB LEDs and an Amazon Echo Dot. As with the previous post, it’s likely some commenters will be upset that a vintage piece of gear has been gutted for this project. But we’d counter that by saying his family is going to get a lot more enjoyment out of this beautiful piece of hardware now than they would have if it was still collecting dust in a closet.

the 3 needle ammeters that make up the face of the clock

IC Clock Uses Ammeters For A Unique Time-Telling Display

September 10, 2021 by Jim Heaney 24 Comments

It is a rite of passage for hackers to make a clock out of traditionally not-clock items. Whether it be blinking LEDs or servos to move the hands, we have all crafted our own ways of knowing when it currently is. [SIrawit] takes a new approach to this, by using ammeters to tell the time.

The clock is built using mostly CMOS ICs. A CD4060 generates the 1HZ clock signal, which is then passed to parallel counters to keep track of the hours, minutes, and seconds. [SIrawit] decided to keep the ammeters functioning as intended, rather than replacing the internals and just keeping the needle and face. To convert the digital signal to a varying current, he used a series of MOSFETs connected in parallel to the low side of the ammeters, with different sizes of current-limiting resistors. By sizing these resistors properly, precise movement of the needle could be achieved by turning on or off the MOSFETs. You can see the schematics and learn more about how this is achieved on the project’s GitHub page (at the time of writing, the most recent commits are in the ‘pcb’ branch).

In addition to the custom PCB that holds all the electronics, PCBs help make up the case as well. While the main body of the case is made out of a repurposed junction box, [SIrawit] had a PCB on an aluminum substrate manufactured for the front panel. While the board has no actual traces or electrical significance, this makes for a cheap and easy way to get a precisely cut piece of aluminum for your projects, with a sharp-looking white solder mask to boot.

We love to see cool and unique ways to tell the time, such as using Nixie Tubes to spell out the time in binary!

Continue reading “IC Clock Uses Ammeters For A Unique Time-Telling Display” →

Raspberry Pi Powered Standing Desk Rises To New Heights

August 18, 2021 by Matthew Carlson 15 Comments

Like many office workers, [David Kong] found himself the lucky recipient of a motorized sit-stand desk. Also like most office workers with such a desk, he found himself mostly sitting. Reminders on his phone did little to change habits and [David] resolved to automate his desk to rise on a schedule.

Taking off the front panel of the control box required a few screws and [David] was delighted to find some testing pins right on the PCB.By connecting the right pins together, he could simulate any button being pressed. A Toshiba TLP222A solid-state relay made it simple to connect the pins together, the next step was triggering the relay on some sort of timer.

Speaking of timers, the oft-lauded 555 timer was considered. However, the length of time desired wasn’t as well suited for the 555, and the appeal of just tweaking a file to adjust the interval was tempting. Going to the other end of the spectrum, [David] had a Raspberry Pi zero laying around he had been meaning to play with.

After soldering the relay to pin 17 and writing a quick 10 line python script that is executed on startup, [David] had a working solution that could be taped to the underside of the desk, out of sight. Rather than being on a fixed timer, the desk raises every 45 to 60 minutes. The impact on his life has been wonderful, which was the goal of this particular project. It’s been a few months and he hasn’t had to tweak or fix anything. Is a whole 64-bit multicore processor a bit of an overkill for toggling a pin every hour or so? Yes. But we can’t really fault him for reaching for what was already lying around. The results speak for themselves.

Perhaps this would be something you would incorporate when you’re building your own standing desk?

Teardown: VTech Smart Start

July 12, 2021 by Tom Nardi 12 Comments

Regular readers may be aware that I have a certain affinity for vintage VTech educational toys, especially ones that attempted to visually or even functionally tie in with contemporary computer design. In the late 1980s, when it became obvious the personal computer was here to stay, these devices were seen as an affordable way to give kids and even young teens hands-on time with something that at least somewhat resembled the far more expensive machines their parents were using.

A perfect example is the PreComputer 1000, released in 1988. Featuring a full QWERTY keyboard and the ability to run BASIC programs, it truly blurred the line between toy and computer. In fact from a technical standpoint it wasn’t far removed from early desktop computers, as it was powered by the same Zilog Z80 CPU found in the TRS-80 Model I.

By comparison, the Smart Start has more in common with a desktop electronic calculator. Even though it was released just two years prior to the PreComputer 1000, you can tell at a glance that it’s a far more simplistic device. That’s due at least in part to the fact that it was aimed at a younger audience, but surely the rapid advancement of computer technology at the time also played a part. Somewhat ironically, VTech did still at least attempt to make the Smart Start look like a desktop computer, complete with the faux disk drive on the front panel.

Of course, looks can be deceiving. While the Smart Start looks decidedly juvenile on the outside, that doesn’t mean there aren’t a few surprising technical discoveries lurking under its beige plastic exterior. There’s only one way to find out.

Continue reading “Teardown: VTech Smart Start” →

Chip Transplant Brings Timex 2048 Back From Grave

July 12, 2021 by Tom Nardi 16 Comments

The 1984 Timex Computer 2048 that [Drygol] recently got his hands on was in pretty poor shape. Not only did it have the mangled exterior that comes from several decades of hard use and furious typing, but the internals appeared to be shot as well, with the machine showing nothing but vertical lines when powered up. Thankfully, this retro computer virtuoso was more than up to the challenge of bringing it back from the brink.

After a good cleaning and the installation of a reproduction front panel, the Timex was already looking much better. Unfortunately [Drygol] says he doesn’t currently have the equipment necessary to touch up the graphics and lettering on the key caps, but the fact that he had to qualify that statement with “currently” has us all sorts of excited to see what he’s planning down the line.

Of course beauty is only skin deep, and this particular TC-2048 was still bad to the bone. [Drygol] had a hunch its Z80 processor was dead, but after swapping it and its socket out, the machine still wouldn’t start. Though he did note that the garbled graphics shown on the screen had changed, which made him think he was on the right track. He then replaced all the RAM on the board, but that didn’t seem to change anything.

There isn’t a whole lot else to go wrong on these old machines, so the final step was to try and replace the ROM. Sure enough, after installing a new Winbond W27C512 chip with the appropriate software burned onto it, the nearly 40 year old computer sprang back to life.

Another classic computer saved from the trash heap, but it’s all in a day’s work for [Drygol]. Over the years we’ve seen him perform meticulous repairs on computer hardware that any reasonable person would have given up on. Even if you’re not into retro hardware, his restorations are always full of fascinating tips and tricks that can be applied when repairing gadgetry from whatever era happens to tickle your fancy.