“I’ve always been fascinated by the early days of the computer revolution. Today we take tremendously powerful machines for granted but it was not always that way. As a personal project I decided to implement an early eighties era microcomputer on the Arduino Uno to demonstrate just how powerful even the most basic of our microcontrollers are today.
My microcomputer of choice was the Apple II, this was the computer that was responsible for making Apple Computer a household name, with over five million units sold it was one of the most popular microcomputers of the era.
The Apple II was originally designed in 1977 by Steve Wozniak. In order to reduce costs and to bring the computer into the mass consumer market, Steve made many unique design decisions that reduced the cost and complexity of the machine. One of these goals was to drastically reduce the chip count of the machine.
The first Apple II machines featured 4 kilobytes of RAM that was shared with the video frame buffer. For CPU it featured a MOS 6502 clocked at 1 MHz. It was capable of generating text video at a resolution of 40 columns and 24 rows, and it featured two graphics modes capable of indexed colour video at up to 280×192 pixels.” …