The 76477 Complex Sound Generation chip (1978) provided sound effects for Space Invaders and many other video games. It was also a popular hobbyist chip, easy to experiment with and available at Radio Shack. I reverse-engineered the chip from die photos and found some interesting digital circuitry inside. Perhaps the most interesting is a shift register based white noise generator, useful for drums, gunshots, explosions and other similar sound effects. The chip also uses a digital mixer to combine the chip’s different sound generators. An unusual feature of the chip is that it uses Integrated Injection Logic (I2L), a type of digital logic developed in the 1970s with the goal of high-density, high-speed chips.
Inside the 76477 Space Invaders sound effect chip
2018-05-19 Hardware 2 Comments
Ken’s blog is always a pleasure to read and very in-depth. Nice!
Thanks for that link Thom.
Interesting, if very limited chip. SID is possibly the coolest I’ve come across with it’s combined digital and analogue. By comparison AY/SN etc sound a bit “SFX” not “Music” by comparison. No doubt some brilliant stuff has been done on the AY.
I was a little surprised to see instrument packs turning up for various synths/iOS apps emulating old chips for a whole new market.
I guess chiptunes reall are “a thing”!
Forgive me. I used to have an account here but lost access to the email. I’ve been reading for years so I figured I should just create a new account and start posting again.