Making a Space Invaders Synthesizer #ArcadeGames #SpaceInvaders #Vintage @Make
Via Make, Charles Platt writes about the SN76477 chip which turns 40 years old. Made by Texas Instruments, the chip was marketed for sound effects in arcade games, including the classic Space Invaders.
Just send high or low signals from an Arduino or any other 5V microcontroller, and you can sequence a cacophony of rifle shots, sirens, the puffing of a steam locomotive, and a sentimental lullaby. Better still, all of the sounds will share that retro arcade ambience.
Apply a 9V battery, and the chip contains its own voltage regulator which converts the power to 5V internally and also makes it available (up to 10mA) from a 5V output. This you can use to power the logic inputs.
Sound from the chip has to be amplified, and the manufacturer recommends (on the datasheet) using a couple of transistors. I found that a single 2N3904 would work.
Platt shows that you can hook the chip up to discrete components to make a synthesizer.
Despite the age and obsolescence of the SN76477, you can still buy samples from multiple eBay suppliers for around $15.
So now if you’ve been putting off the chore of synthesizing the sound of a crashing car while an electronic organ plays “Twinkle, Twinkle, Little Star,” you have no further excuses. The SN76477 can do it all.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.