Digirule 2 & 2A

I have been fascinated with systems like the Altair 8800 for some time now and decided to up-the-anti with my second iteration of the Digirule by making a programmable binary computer built into a PCB ruler. The Digirule 2 and 2A are identical with respect to their hardware however the Digirule 2A comes pre-programmed with updated firmware (made by Brent Hauser) and also updated PCB silkscreen.

I no longer have any of the Digirule 2 rulers for sale since I have upgraded it to the Digirule 2A. You can purchase a Digirule 2A from my Tindie store by clicking the link below:

I sell on Tindie

The Digirule 2/2A are open source, and you can find all the download links you need at the bottom of this page (just before the comments section).

Image source: Wikipedia

The Digirule 2 was successfully funded on Kickstarter on 28th June 2018 where 487 backers pledged $22,097AUD. Kickstarter link HERE.

The Digirule 2A was successfully funded on Kickstarter on 29th May 2019 (which only ran for 48 hours!) where 149 backers pledged $6,149AUD. Kickstarter link HERE.

The Digirule 2/2A can be likened to a computer similar to the Altair 8800 built into a 20cm ruler. They are essentially an 8-bit programmable binary computer with a simple instruction set that let’s you add, subtract, AND, OR, XOR, shift, check buttons, check the status of flags etc. so you can make some cool little programs that can be stored even when power is turned off by using the inbuilt flash memory. An excel spreadsheet helps to convert code to binary for you to then enter on the Digirule 2/2A. The original Digirule 2 firmware contains 33 instructions while the updated Digirule 2A firmware contains 35 instructions.

Check out the preview video below:

Digirule2 Front and Rear

Digirule 2A Front and Rear



Digirule2 Files including sourcecode, schematic, PCB design, gerber, user manual and excel spreadsheet coder.

Digirule2Files.zip (1848 downloads)

User Uploads

If you’ve made a program that you’d like to share with others, feel free to upload it using the form below:

Upload files

You can browse the user upload directory by clicking HERE.

Digirule2 Assembler

Luke Drumm has made a fantastic Digirule2 Assembler and can be found HERE.