Here is my take on 80's home computer magic: The most computer from the least logic or the shortest way from TTL to Space Invaders.
Introductory videos: https://www.youtube.com/watch?v=3zGTsi4AYLw, https://www.youtube.com/watch?v=FJsnKu20ch8
Reference manual: https://docs.google.com/document/d/1e4hL9Z7BLIoUlErWgJOngnSMYLXjfnsZB9BtlwhTC6U/edit?usp=sharing
Visit my YouTube channel: https://www.youtube.com/channel/UCXYQcMpUBT3aaQKfmAVJNow
Like this project and want to give something back? https://www.paypal.me/carstenherting
FEATURES
● Only 56 74HCxx logic ICs, 1x 6C1008 SRAM, 4x 39SF0x0 FLASH, BUT NO MICROCONTROLLER!
● Textbook 'Von-Neumann' architecture, 8-bit data bus, 16-bit address bus, 24 control signals
● 64KB RAM, 512KB FLASH SSD with file system (format, load, save, dir, delete)
● Monochrome VGA output 400 x 240 pixels, PS/2, expansion slot and serial UART port
● 8MHz system clock, 6MHz CPU clock with 0.84Mips (2x Commodore 64)
● 128 instructions including conditional branching, subroutines, stack and word operations
● 2 data registers A, B plus two more "software" registers X, Y
● ALU supporting ADD, SUBTRACT, AND, OR with 3 flags (negative, carry and zero)
● Full native tool-chain: MinOS, text editor, assembler, fast Python-like interpreter 'MIN'
● Emulator, cross-assembler (Windows) and classic games (TETRIS clone, Space Invaders clone)
● Open-source emulators in JAVA/PROCESSING and JAVASCRIPT/p5.js https://editor.p5js.org/slu4coder/full/aOUivViNt
Have fun!