Emulate a vintage ROM or EPROM with a Raspberry Pi Pico and CircuitPython #CircuitPython #PiDay #RaspberryPiPico @E14Community @baldengineer
The Apple IIe uses a custom microcontroller and ROM chip to put ASCII values from the keyboard into the computer’s memory. How can this function be emulated?
How hard could it be to replace that dual-chip setup with a microcontroller to emulate another kind of keyboard? Bald Engineer tries using an Arduino Mega 2560, Teensy 4.0, and a Pi Pico to replace a vintage ROM chip. See what works AND what does not!
Spoiler alert – of all the candidates, even the Teensy 4.0, the $4 Raspberry Pi Pico did it! With PIO, it’s fast enough to perform the needed timing!
And the amazing thing is that CircuitPython is used to program the PIO and direct the data, even being an interpreted language!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.