This Handheld C64 Design Study Needs To Be Made

The Commodore 64 remains the best selling home computer of all time, and is unlikely to be toppled anytime soon. It continues to inspire a diehard community of makers and hackers to this day. [Cem Tezcan] is one of those people, and his design study of a handheld C64 is utterly droolworthy.

It’s quite likely that you’d run out of power before the cassette finished loading, but hey, we can dream.

The study includes renders of the device from several angles, as well as a basic blueprint outlining the various components. It features period accurate hardware, using a membrane keyboard, micro-cassettes for data storage, and a 3.5″ CRT. Other nice touches are the big red textured FIRE button, and a horrible early 80s 3.5mm jack.

The C64 hardware of the time required both 12 V and 5V power, and the current draw of even a small CRT would be high. It’s likely such a handheld would have battery life measured in minutes. It’s a wonderful picture of what could have been, though we suspect that such a design would have pushed the limits of the technology of the time.

However, electronics has matured since, and we sit here rather comfortably in 2019. We’d love to see the best handheld C64 that the community can muster, and with 3D printers and FPGAs on hand, it’s an eminently achievable feat. Bonus points to anyone who can make a microdatasette interface, too. All submissions to the tips line, and meanwhile, consider how easy it is to build a new C64 from scratch. Happy hacking!

55 thoughts on “This Handheld C64 Design Study Needs To Be Made

    1. I have a side-fire Sony Watchman on the shelf. Been probing around to figure out where the video, hsync and vsync videos are on the board so I don’t need to use some janky RF adapter. That would be perfect for this! It’s such a cool little tube. Instead of projecting the electron beam on the backside of a phosphor coating on the front of the glass, it projects on a curved screen behind the glass on the back of the tube. So it’s kind of reflective instead of transmissive. It’s a very cool little CRT, and quite sharp. Would have to be monochrome, though—dunno how you’d be able to put a shadow mask and three guns on it for full color. And an LCD color screen would probably have too much parallax and curvature difference between the front of the glass and the curved screen a half-inch behind it.

      https://www.experimental-engineering.co.uk/wp-content/uploads/2016/08/2016-08-16_21-52-28_000289.jpg

      Looks way better than this photo. Much more contrast. It’s so crispy and sharp.

      1. Came here to say the same. I used a Watchman in a night vision project that I did about 10 years ago with a Sony EXview camera (I call it the Night Watchman, hehe). Found a schematic and was able to input my own video signal. If I can find the schematic, or get a chance to open up that device again, I’d be happy to share.

        1. Ha, Night Watchman—I love it! That’s pretty cool. I think I could probably probe around and find a composite trace, or at least a video and hsync/vsync traces. But if you might have the schematic, I’d definitely appreciate that. My model is a Sony FD-230, serial no. B279329.

          https://imgur.com/a/rIiD7xy

          Here’s some crappy pictures of the tube and driver board. There’s a couple little viewfinder CRTs in that box, too.

      2. A small, low power, high efficiency, single gun, color CRT could have existed at the time, but for a nasty patent fight between Philco and David Sunstein, a former employee and developer of the “Apple CRT” or “Uniray”.
        Development began in the early 1950s and a functional prototype was built in 1957. If not for their disagreements this technology would have had dramatic effects on the TVs we had in the 60s and 70s.
        Imagine a Sony Trinitron with a single electron gun available in 1960!

        https://www.earlytelevision.org/uniray.html

        1. Beam indexing CRT technology did eventually make its way into the world through several manufacturers, but only in specialty markets, such as the Ferranti 4×3 mapping display in the Panavia Tornado and the viewfinder displays in some Sony camcorders(Indextron). This was due to its inherent resistance to local magnetic disturbance.
          A great candidate for this project would have been the Sanyo “Lollipop” tube, seen here towards the bottom of the page: https://visions4netjournal.com/indextron/
          A 3″ display only 1-1/2″ deep would have worked quite well in this case, provided you made space for the neck under the keyboard.

        2. Wow, that’s super interesting. And a very simple design, kind of seems absurd now to use three guns and a shadow mask. Bad IP law strikes again! Ah well. Thanks for bringing this little design marvel to my attention, by the way!

      3. Aren’t flat Sony Watchman mono only? AFAIK flat color CRT was in the development but abandoned when color LCD were getting cheap in the late 80s. So the smallest color CRT are I think 4″ and its neck would be a lot longer than the concept HX-64 could house.

      1. Oh yeah, I’ve seen one of those. The tube is also way cooler, love how the envelope is totally rectangular and you can look at all the components of the electron gun and beam steering hardware. Somewhat hard to find these days unfortunately.

  1. The C64 came out in 1982. By that time, we had CMOS 6502’s, 32k static CMOS RAMs, 74HC logic, and all the other low-power chips needed. Power consumpution of the computer itself would certainly not be a problem, if the designer was willing to use the more expensive CMOS chips.

    The most challenging aspect would be the screen. There were certainly B/W CRTs that were low-power and small enough (the Sony Watchman came out in 1982). There were also color CRT’s; but they were much deeper and used a lot more power. LCDs were only B/W in 1982. It took several more years before color LCDs reached the market.

    1. Not only is it simply too small to accommodate the CRT, but the rest of the photos show that all the space where that screen is supposed to live is also taken up by all the peripheral connectors, speakers and the expansion port :-/ Design without regard for reality at all.

      1. The micro-cassettes as a storage method probably wouldn’t have worked too well either, as they have an even worse dynamic range and frequency response than the ordinary compact-cassettes most of us are familiar with, with the added “bonus” of being too short in duration to record much of a program onto.
        This is a cool looking industrsial design project, but I must concur that it is really outside the realms of technology of that day (the early to mid 1980’s).

      2. It also has a tiny chicklet keyboard, which is somewhere in the top tier of pain for attempting to type on. I bought a “pocket CHIP” when they were a thing, and that tiny little keyboard is an absolute misery to use.

  2. Best selling home computer of all time. Commodore 64 is not selling anymore.
    According to wiki: Sales of 12.5 to 17 Million
    -vs-
    Raspberry Pi computer still selling and producing.
    According to wiki: Sales totaling 19 Million as of 2018.

    So how can Commodore claim top spot when it was dethroned over a year ago ?
    Not saying the 64 is a bad computer. I would love to have a working one.
    But reality is Raspberry PI 1, beat out 64 and IBM PC 1 functionality from day 1.

    If anybody wanted to start out with a nice computer to learn Linux. The PI 4 with
    4GB is the best one yet.

    Wish people would stop say “Best selling home computer”.
    Commodore had great sales, Raspberry has better, but:
    IBM PC and clones has even many times better sales then all of them combined.
    Granted IBM sells to business, industrial and home. Only counting the home
    market IBM outsells them by factors.

    1. That line caught my attention too. But paused to ponder, “by what definition?” Raspberry Pi is certainly a computer, but the C64 has a keyboard and actually usable out of the box (even without a monitor, you could power it on and type blind to run a program).

      The title and accolade of being the best selling isn’t important to me. Just thought the question of semantics was sort of interesting.

      1. You seem to be going by a retro-definition.

        I can’t recall if “home computer” was literally used early on, but it was implied. That’s from the point of tye Altair 8800, or maybe even the Mark-8.

        These were aimed at hobbyists, they played with them at home. They weren’t for everyone, but they were the beginning. They didn’t have keyboards or monitors, they weren’t even ready for them out of the box.

        In 1977 when tge Apple II, Commodore PET, and Radio Shack TRS-80 arrived, they weren’t that different, just a bit more complete and more people could use them. But they weren’t first. Processor Technology’s SOL-20 came a year or two earlier, as did a Sphere all in one.

        But just as some mis-state that those three computers in 1977 were the start of “home computing” or whatever phrase is used, some place it later as if a more popular computer counts more. Just because more kids had C-64s than previous home computers doesn’t define the term.

        It’s been forty years and six months since I got my first home comouter, no ascii keyboard or monitor, and there’s never been a time since that I’ve not had a computer.

    2. I’d argue the Raspi isn’t a *home* computer – or at least, the majority of them aren’t used as such. Id bet the majority of those RasPis are in industrial uses, or are at home unused.
      I’ve not got any stats, but Anecdotally, everyone I know with a raspi has at least 10, none in use as a home computer.

      1. I was considering posting the same comment. I have 2 Pi’s and consider them a hobbyist computer over a home computer. This could change but I don’t think everyone has the same idea of a “home” computer.

    3. The simple answer is that those RasPi sale numbers likely include the original, the Zero, 2, 3, 4 and any other variants that are different enough to be the equivalent of the commodore 128 or vic 20. The IBM PC and clones have a similar problem with a diluted market space.

      While it isn’t exactly the most useful statistic, thanks to shortening upgrade intervals the C64 is still, and likely always will be, the best selling individual model. At least, until computers advance to the point that the general buying public says “You know what? I don’t need anything better than what I’ve got. Just give me another of the same when this one fails.”

    4. A raspberry is not a home computer. It’s an SBC.
      Also as your post implies, the Raspberry Pi is not a single device but a family of devices. You cannot combine the sales of half a dozen or more separate devices with different names and different hardware any more than you can count every computer called Macintosh as a single unit.
      The Commodore 64 was a legitimate home computer with 1 minor variant of the same hardware with identical functionality and only cosmetic differences in the case that sold millions of units under the same name.

  3. I loved the C-64 and later the C-128 and the Amiga, but my true love was the C-64. Today (I am almost 80 yrs old) I use emulators and have every single game for the old 8 bits. My favorite games are Castle Wolfenstein (although I have altered the variables), as well as the Falkland Islands and Iwo Jima. Being retired I have all the time in th world, I find them relaxing.

  4. I’d probably start with a C64 DTV motherboard and PS2 keyboard adaptor. There’s no cassette interface though sadly, so would have to substitute some kind of 1541 drive. Has anyone done a 1541 to 3½” PC drive interface? A 4″ mono CRT TV takes only about 6W. A set of alkalines or NiMh should last a few hours.

    1. You would be correct. I made a power pigtail for my two survivors that allows for use of two separate 5V DC and 9V AC wall warts to replace the factory power brick that was hitting the point of likely damaging the units.

      1. C64 still needs 9v AC to use a few things: Cassette motor and user IO port plus the CIAs use the AC to clock the TOD and count the Jiffies. The first 2 can be left out on mini C64 but AC signal (60 or 50 hz) is still needed for full C64 functionality.

          1. It’s been done about thirty years ago.

            Someone wanted to run off batteries, so he used a color subcarrier crystal and that IC that divided it down to 60Hz (designed for digital clocks).

  5. I think people are misreading this. Of course this woukdn’t exist in 1982, cost if nothing else would be prohibitive. But a few years later, maybe. Lots of computers evolved while keeping the same basic design. Some of it was because demand needed lower price, some of it was streamlining costs, as components became denser, some were mild imorovements.

    The portable C-64 is an example, aiming at a slightly different buyer. Not much change there, but as LCD displays improved, a few more years might have done this. The Radio Shack Model 100 came out in 1983, a mix of moving forward, and backward from the C-64. But proof that a portable was almost viable concurrent with the C-64. And static RAM did become denser around that time, though it would require a redesign. Someone pointed out the 65C02 was available, so the real issue was maybe some perioheral ICs, the screen, and maming it small.

    1. I have one. It’s heavy, not really portable, and has a few minor differences that could break picky games (default screen color, different ROM code) and incorrectly wired user port.

      1. As someone who used to own a Compaq Portable, I totally understand that the SX is not only heavy but not exactly a portable, other than you can carry it like a suitcase. I mostly want one for nostalgia’s sake, as it was the first C64 I really spent any time with. Eventually, I had a C64 of my own, but still wanted that SX!

  6. Being an original C64 user back in the day. I hated when this company went under, I was excited about the C64 Linux project. I heard that went belly up as well. I think if Pine Book Pro and Commodore got together some great old school gaming would make a decent showing.

  7. CRTs were not THAT power hungry. Portable sets ranging from 3 to 5 inches existed back in the 80’s/90’s that could run off a set of 6 or 8 C cells for several hours at a time. Adding the digital electronics of a computer of the era, I would expect you could still get 2-3 hours of work time off such a setup.

  8. As previously stated, a color CRT of that size and form factor is not feasible or even desirable. But if it’s just the curved “genuine” look of a CRT, that’s easy enough to achieve with correct shaped front glass and an LCD behind it. IE:

    https://www.youtube.com/watch?v=-mMaO6ULuSk

    Looks way better than the many “hackintosh” LCD’s stuffed in the case hacks, but requires a bit more work (and dealing with some toxicity).

    https://www.youtube.com/watch?v=3grAxKGzBt0

    But with properly shaped new glass, a CRT-‘looking’ display is doable.

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