[Stephen Edwards] had some time one Christmas. So he took a DE2 FPGA board and using VHDL built a pretty faithful reproduction of an Apple II+ computer. He took advantage of VHDL modules for the 6502 CPU and PS/2 keyboard, and focused more on the video hardware and disk emulation.
According to [Stephen], you can think of the Apple II as a video display that happens to have a computer in it. The master clock is a multiple of the color burst frequency, and the timing was all geared around video generation. [Stephen’s] implementation mimics the timing, although using more modern FPGA-appropriate methods.
