Supercon 2023: Restoring The Apollo Guidance Computer

November 6, 2024 by 17 Comments

Humans first visited the Moon in 1969.  The last time we went was 1972, over 50 years ago. Back then, astronauts in the Apollo program made their journeys in spacecraft that relied on remarkably basic electronics that are totally unsophisticated compared to what you might find in an expensive blender or fridge these days. Core among them was the Apollo Guidance Computer, charged with keeping the craft on target as it travelled to its destination and back again.

Marc Verdiell, also known as CuriousMarc, is a bit of a dab hand at restoring old vintage electronics. Thus, when it came time to restore one of these rare and storied guidance computers, he was ready and willing to take on the task. Even better, he came to the 2023 Hackaday Supercon to tell us how it all went down!

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A Birthday Cake For A Retrocomputer Designer

October 25, 2024 by 6 Comments

When making a birthday cake a bit more personal, one can create a novelty themed confection appropriate for the lucky recipient. In the case of [Spencer Owen], who you may know as the creator of the RC2014 retrocomputing ecosystem, it was appropriate to have one of the little machines at work somewhere, so [peahen] did just that. The result is a cake in the shape of an IMSAI 8080 microcomputer, but it does more than just look the part. This is a working replica of the classic machine, powered as you might expect by an RC2014 sitting next to it.

The lights are a set of addressable LEDs, and the switches are made from appropriately colored sweets. Sadly the plan to make these capacitive touch switched failed as the wiring became buried in the icing, but the LEDs deserve a second look. They’re encased in translucent heatshrink sleeving which is embedded under a layer of white icing, which is translucent enough, but on top for the classic panel light look are a set of edible cake-maker’s jewels. Best of all while all except the electronics is edible, the front panel is robust enough to have been removed from the cake in one and thus will live on.

We rather like the idea of electronics meeting sugarcraft, because fondant is a surprisingly versatile medium that deserves attention much further than just confectionery. We remember it being a popular cheap way to experiment with 3D printing back at the dawn of open source printers, and it still has some potential. Meanwhile if you’ve not seen the RC2014 we reviewed its original version back in 2016, and since then it’s evolved to become an ecosystem in its own right.

Strange English Teaching Computer Might Have Been Big In Japan

October 21, 2024 by 9 Comments

[Ctrl-Alt-Rees] bought something strange on an auction site: a Japanese Cefucom-21 from 1983. No? Didn’t ring a bell for us either. The legend on the front boldly proclaims: “CCI Multipurpose SLAP Computer,” so maybe it is some kind of computer, but it is definitely strange. For one thing, the “screen” isn’t a screen at all. [Rees] has found that it has something to do with teaching English. You can see the odd beast in the video below.

We don’t know how common these were in Japan, but they appear to be virtually unknown everywhere else. Inside is a Z80 computer based on a  Sanyo PHC-25, which is a little better known.

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Where Did The Japanese Computers Go?

September 22, 2024 by 23 Comments

If you are a retrocomputer person, at least in North America and Europe, you probably only have a hazy idea of what computers were in the Japanese market at the time we were all buying MSDOS-based computers. You may have heard of PC-98, but there were many Japanese-only computers out there, and a recent post by [Misty De Meo] asks the question: What happened to the Japanese computers?

To answer that question, you need a history lesson on PC-98 (NEC), FM Towns (Fujitsu), and the X68000 (Sharp). The PC-98 was originally a text-only MSDOS-based computer. But eventually, Microsoft and NEC ported Windows to the machine.

The FM Towns had its own GUI operating system. However, it too had a Windows port and the machine became just another Windows platform. The X68000, as you may well have guessed, used a 68000 CPU. Arguably, this was a great choice at the time. However, history shows that it didn’t work out, and when Sharp began making x86-based Windows machines — and, of course, they did — there was no migration path.

[Misty] makes an interesting point. While we often think of software like Microsoft Office as driving Windows adoption, that wasn’t the case in Japan. It turns out that multitasking was the key feature since Office, at the time, wasn’t very friendly to the native language.

So where did the Japanese computers go? The answer for two of them is: nowhere. They just morphed into commodity Windows computers. The 68000 was the exception — it just withered away.

Japanese pocket computers were common at one time and have an interesting backstory. Japanese can be a challenge for input but, of course, hackers are up to the challenge.

Usagi Electric’s Paper Tape Reader Is Ready To Hop With The Tube Computer

September 16, 2024 by 25 Comments

After previously working out a suitable approach to create a period-correct paper tape reader for his tube-based, MC14500B processor-inspired computer, [David Lovett] over at the Usagi Electric farm is back with a video on how he made a working tape reader.

The assembled paper tape reader as seen from the front with tape inserted. (Credit: David Lovett, Usage Electric, YouTube)
The assembled paper tape reader as seen from the front with tape inserted. (Credit: David Lovett, Usage Electric, YouTube)

The tape reader’s purpose is to feed data into the tube-based computer, which for this computer system with its lack of storage memory means that the instructions are fed into the system directly, with the tape also providing the clock signal with a constant row of holes in the tape.

Starting the tape reader build, [David] opted to mill the structural part out of aluminum, which is where a lot of machining relearning takes place. Ultimately he got the parts machined to the paper design specs, with v-grooves for the photodiodes to fit into and a piece to clamp them down. On top of this is placed a part with holes that line up with the photodiodes.

Another alignment piece is added to hold the tape down on the reader while letting light through onto the tape via a slot. After a test assembly [David] was dismayed that due to tolerance issues he cracked two photodiodes within the v-groove clamp, which was a hard lesson with these expensive (and rare) photodiodes.

Although tolerances were somewhat off, [David] is confident that this aluminum machined reader will work once he has it mounted up. Feeding the tape is a problem that is still to be solved.  [David] is looking for ideas and suggestions for a good approach within the limitations that he’s working with. At the video’s end, he mentions learning FreeCAD and 3D printing parts in the future.  That would probably not be period-correct in this situation, but might be something he could get away with for some applications within the retrocomputing space.

We covered the first video and the thought process behind picking small (1.8 mm diameter) photodiodes as a period-correct tape hole sensor for a 1950s-era computing system, like the 1950s Bendix G-15 that [David] is currently restoring.

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Large Language Models On Small Computers

September 7, 2024 by 6 Comments

As technology progresses, we generally expect processing capabilities to scale up. Every year, we get more processor power, faster speeds, greater memory, and lower cost. However, we can also use improvements in software to get things running on what might otherwise be considered inadequate hardware. Taking this to the extreme, while large language models (LLMs) like GPT are running out of data to train on and having difficulty scaling up, [DaveBben] is experimenting with scaling down instead, running an LLM on the smallest computer that could reasonably run one.

Of course, some concessions have to be made to get an LLM running on underpowered hardware. In this case, the computer of choice is an ESP32, so the dataset was reduced from the trillions of parameters of something like GPT-4 or even hundreds of billions for GPT-3 down to only 260,000. The dataset comes from the tinyllamas checkpoint, and llama.2c is the implementation that [DaveBben] chose for this setup, as it can be streamlined to run a bit better on something like the ESP32. The specific model is the ESP32-S3FH4R2, which was chosen for its large amount of RAM compared to other versions since even this small model needs a minimum of 1 MB to run. It also has two cores, which will both work as hard as possible under (relatively) heavy loads like these, and the clock speed of the CPU can be maxed out at around 240 MHz.

Admittedly, [DaveBben] is mostly doing this just to see if it can be done since even the most powerful of ESP32 processors won’t be able to do much useful work with a large language model. It does turn out to be possible, though, and somewhat impressive, considering the ESP32 has about as much processing capability as a 486 or maybe an early Pentium chip, to put things in perspective. If you’re willing to devote a few more resources to an LLM, though, you can self-host it and use it in much the same way as an online model such as ChatGPT.

CL-32: The Minimum Possible For A Useful Handheld Computer

September 1, 2024 by 19 Comments

For almost as long as there have been microcomputers, there have been attempts with varying success to make tiny handheld microcomputers. Sometimes these have been very good, and other times they’ve missed the mark in some way. Latest to find its way to us is the CL-32 from [Moosepr], it’s a handheld computer with an ESP32 as brains, an electronic paper display, and a QWERTY keyboard in its smart printed case.

The hardware is relatively standard, save for the keyboard which is a dome-switch design in which the membrane carrying the domes is hand-made. We like this, and don’t think we’ve seen anyone else doing that. Expansion is taken care of by a novel socket arrangement in which boards nestle in a recess in the surface. Some experimentation was required as always to drive the display, but the result is a functional computer.

Sadly there’s little detail in terms of what the software will be, and no hardware files as yet. But what we can see is promising enough to make this one to watch, so we’ll look forward to what they come up with. If an ESP32 OS is a problem, there’s always badge.team, who have been continuously improving theirs since 2017.