The Pocket265 Is A Pocket-Sized 6502 Single-Board Computer

Front and back of a handheld 6502 computer with bubble LED displays

Single-board computers have been around ever since microprocessors became affordable in the 1970s and never went away. Today we have Raspberry Pis and LattePandas, while back in the ’70s and ’80s there were the Ferguson Big Board, the KIM-1 and a whole array of Intel SDK boards. Although functionally similar to their modern counterparts with a CPU, RAM, ROM and some basic peripherals, the old boards were huge compared to today’s tiny platforms and typically required a rather beefy power supply to operate.

It doesn’t have to be that way though, as [Aleksander] shows with the Pocket265: a handheld 6502 single-board computer somewhat reminiscent of the famous KIM-1. Like that classic machine, it’s got a hexadecimal keypad to enter programs using machine code and a row of LED displays to show the programs’ output. Unlike the KIM, the Pocket265 is small enough to hold in one hand and uses bubble LED displays, which make it look more like a programmable calculator from the 1970s. It comes with a lithium battery that makes it truly portable, as well as a sleek 3D printed case to make it more comfortable to hold than a bare circuit board.

The single ROM chip contains a monitor program that runs the basic user interface. It also makes programming a bit less tedious by implementing a number of system calls to handle things like user input and display output. A serial EEPROM enables local data storage, while a UART with a USB interface enables data transfer to other computers. If you’re interested in building and programming such a machine yourself, [Aleksander] helpfully provides code examples as well as full hardware documentation on his GitHub page.

The 6502 remains a firm favorite among hardware hackers: some projects we recently featured with this CPU include one beautifully made machine, this easy-to-build single-board computer and this huge breadboard-based contraption. Looking for something smaller? Try this tidy little board or this 6502 coupled to an FPGA.

13 thoughts on “The Pocket265 Is A Pocket-Sized 6502 Single-Board Computer

  1. In 1980, someone I knew had a terminal the size of a calculator. I think LED display. He used it to configure Intersil 6100 boards he was manufacturing to sell to a record plant to modernize their operation.

    1. I have kind of wished that narrower ones were available like what I show in the middle of the page at . For a much, much higher price, you can get the narrow size in a serial-interfaced dot-matrix display from Broadcom, so you can display upper- and lower-case and all the special characters (even your own custom ones) that will fit in a 5×7 matrix for each character position. I have a couple of samples here. See

        1. You’d have to add a microcontroller to read the continually strobed digit & segment signals and translate them into a dot pattern and feed them serially into the Broadcom display. It could be done, but it would be quite a project. BTW, these displays have a serial in _and_ out so they can be daisychained. Mechanically they are also end-to-end stackable, so you can get as many characters as you want (or can afford, LOL).

    1. I agree, I wanted lipo socket too. There is a 2-pin JST socket in the project, but due to slight miscalculation it doesn’t fit. Welp, it’s a first prototype, something had to go wrong :)

  2. Now you have me itching for a calculator style interface board. Keys, display, and power regulation (power rails, battery monitor & recharge).
    Leaving CPU, RAM, and other peripherals on a SBC that sits below. Portable, modifiable, versatile.

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