Arbitrary waveform generator designed by NiHaoMike is a Open 7400 competition entry. It uses a serial link with a computer to load up a W24512A SRAM IC which is then clocked out into a TLC7524 digital to analog converter.
This is really just for fun – it doesn’t make a very good function generator by modern standards. (If I wanted something to actually use, I would start with a FPGA…) Apart from that, however, it can generate a number of waveforms that an old analog function generator cannot. It uses a PC with a serial port to supply the waveform data.
Build something that uses or abuses a logic chip and get amazing boards, tools, and other swag. The Open 7400 Logic Competition promotes awareness of the basic building blocks of modern circuits. Devious geeks ignited the computer revolution with discrete logic computers, what can you do? Details and entry form here.