The Picodore 64 – a Commodore 64 PDA

This post is my first attempt to document the design and construction of my Picodore 64. It’s a Commodore 64 based PDA / Palmtop. Really, all the hard stuff was already done before I joined the DTV hacking scene, I just stuck it all together in a nice small package.

Here are the specs:

Mainboard: Hummer DTV
Construction: Hobby plywood covered in faux stainless steel contact paper
Size: 6.5″ x 6″ x 1.5″ (closed)
Power: 7.5v wall adapter or 6 rechargable AA NiMH batteries
Screen: 5″ LCD Keyboard: 69-key QWERTY Sound: Ampilfied 1.5″ 0.4W internal speaker

Connections: power, userport/joystick, serial disk drive, audio/video output, headphone jack, external PS/2 keyboard, SD card slot.

Addition peripherals: 1.75″ x 1.5″ mini Atari joystick.

Features: on screen display for volume and brightness control, auto sensing of external keyboard connection, programmable funtion keys, video selector switch.

Although I plan on posting a more length write-up, for now, I’ll give you just the important details:

The LCD screen is from a PSOne. I’m also using on LCD’s board audio amp to drive the speaker.
The LCD is what ultimately drove my power requirements. Almost the entire circuit for the LCD uses 5v except for one IC which needs between 7v and 8v to generate H-Sync.

The keyboard was a bitch to figure out and will be the subject of a post of it’s own. It’s from a Jornada foldaway keyboard made by Micro Innovations. In terms of construction, I had cut away a lot of extra plastic and superglue the two halves together making a single solid keyboard. The keyboard normally interfaces with a HP Jornada via a RS-232 link and special driver. I was able to capture all the output codes and program a 16F88 PIC microcontroller to re-map and output with the appropriate PS/2 protocol. On power up, the PIC checks if there is an extrenal keyboard attached. If so, it ignores data from the onboard keyboard.

If you more in depth details of the RS-232 to PS/2 keyboard hack check on this post.
Some other general construction details can be found here.

I have set up a DTV Hacking Wiki here. Also, here is a forum specifically geared toward answering basic questions about hardware hacking.



This is what I started out with. I got it from Radio Shack on clearance for $17.99.

After all the sawing, sanding and filing, I think I would have been better off just carving it out of a log.


All the major components can be seen here.

This is the backside of the keyboard panel. You can also see the speaker hot-glued into position.

Check out that sweet miniature Atari joystick! It’s fully functional by the way.
What project would be complete without an SD card slot.

The keyboard on the bottom is a normal sized PC keyboard. Initially, I was going to use the one in the middle since it was the smallest PS/2 keyboard I could find, but believe it or not, it wasn’t small enough!
Here is a close up of the to show some of those awesome decals. Note the “C64 inside” logo on the right.

Here’s the view when closed.

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3 Responses to The Picodore 64 – a Commodore 64 PDA

  1. se-po says:

    Well, amazing :-)
    I came here from an Italian web-magazine http://tinyurl.com/ocs7oh
    nice job! really

  2. Anonymous says:

    Wow, that had to take long. I have an 80286 computer at home, and it's huge, and I think the picodore 64 might be faster. The 286 has 8mhz, (I didn't read the bottom, but I'm getting to that.)

  3. domofreak says:

    i hope u dont mind if iuse youre idea :P (i wont copy its design, ext, but i will make a c64 laptop just because its so awsome XD)