This is an unassembled kit of electronic components and circuit board. Soldering required. There is an assemble option at checkout if you want an assembled unit.

This is a microcode emulation, not a function emulation of the original calculators. I actually do not understand well the very complex calculator logics. I just implement the the original TMS080x 4 bit mcu and have the calculator ROM run against it. I believe the TI DataMath ROM was obtained from a TI patent document, while the Sinclair Scientific ROM was extracted by reverse engineering a 40+ year old chip via acid bath and microscope analysis.

The emulator was created to be;

• An easy-to-build beginner's soldering kit.
• A useful tool as a gift.
• A replica of antique electronic technology.
• Powered by a single CR2032 battery. Deep sleep / off mode consumes about 0.6uA power.

Emulation core is based on Ken Shirriff's work. This is not a new project. This project was done in June 2014. I am creating this page here to link this to a tindie project page and sell the remaining kits I had created over the years.

This kit uses 2 of the now retired HP QDSP-6064 LED module. The PCB was designed to have these LED modules fiction-fit installed instead of soldering. They can be repurpose into other projects and should not be soldered.

Hackaday project entry

Operation Instructions

• now does LPM4 auto-off, can eliminate SPDT slide switch on pcb
• auto-off time is 60 seconds of in-activity. 'C' key to switch on
• move setup function from press-n-hold to 'C' + 5, 6, 7, 8, 9 keys
• setup is pressing 'C' and in very quick succession one of 6, 7, 8, 9 keys
• C+5 = button test ('C'+'C' to end test)
• C+6 = secret message edit (+ key to advance)
• C+7 = toggle datamath / sinclair roms
• C+8 = toggle slow / fast cpu
• C+9 = show secret message
• C+C = turn off (put to sleep)

Assembly / Soldering Instructions

• I suggest NOT to solder the LED modules. The thru-holes are made to fiction-fit them and these is no need to solder them. There LEDs are rare and this will save them for other projects.
• Button on top right corner (73) does not have any function, you can skip soldering it, it is just there for coherence. I also sticky tape one button as an example of how you should bend the pins w/ a pair of long nose pier and fit them in. you should solder them buttons on the top and you will have a smooth bottom. Tape down components can help with soldering.
• Single lone led is a negative sign indicator, observe the polarity, the short (cathode) pin is north.