Very basic C64 emulator
6502 emulation core taken from here.
It emulates the original Commodore 64 Basic. Only text mode is supported, with support for colour (text, border and background). PETSCII support is very hacky, but it can run the famous one-liner maze program. Only 32KB of RAM are available, as bank switching isn't implemented.
Raspberry Pi Pico, ST7735-based 128x160 LCD screen and a PS2 keyboard.
For the screen: RST is GPIO16, CS is GPIO17, DC is GPIO20, SCK is GPIO18, TX is GPIO19.
For the keyboard: DAT is GPIO3, CLK is GPIO2. The keyboard must be connected through a level shifter, otherwise the Pico might get damaged.
After starting, you will be asked to select between the C64 or SX-64 ROM. The only significant difference between the two is the color theme of the BASIC editor.
Pressing PgUp clears the BASIC editor screen.
Pressing ESC while the emulator is running brings up a menu from where you can reset the emulated C64, load some demo programs or automagically type the color selection POKE commands.