Ben Eater Makes Computer Noises

Hand holding small speaker

When [Ben Eater] talks, hackers everywhere listen. In his latest video [Ben] shows us how to make computer noises using square waves and a 6502 microprocessor.

[Ben] uses the timer in the W65C22 Versatile Interface Adapter to generate the square waves which generate a tone. He then adds support for a new BEEP command into his MS BASIC interpreter. We covered [Ben Eater]’s MS BASIC here at Hackaday back in April, so definitely check that out if you missed it.

After checking the frequency of oscillation using his Keysight oscilloscope he then wires in an 8Ω 2W speaker via a LM386 audio amplifier. We can’t use the W65C22 output pin directly because that can only output a few milliwatts of power. [Ben] implements the typical circuit application from the LM386 datasheet to drive the speaker. To complete his video [Ben] writes a program for his BASIC interpreter which plays a tune.

Thanks to [Mark Stevens] for writing in to let us know about this one. If you’re planning to play along at home a good place to start is to build your own 6502, like [Ben] did!

6 thoughts on “Ben Eater Makes Computer Noises

      1. The horn sound in the beginning; how do you think brass instruments work in the first place? What makes the sound? The beatboxing is real – what makes it sound special is feedback and echo effects through the mic.

  1. Beep is fun to play with. I used to write FreeBasic, I remember making a musical octave table, you input the number of equal tempered scale steps in the octave and the root freq. It would play back the micro tones chromatically and show their pitch in hz.

    Ironically I failed math that semester and got a C+ in CS101

    For those interested in “computer noises” look into ByteBeat, granular synthesis, PureData, Miller S Puckette, Curtis Roads, John Chowning. The list is long but these are good places to start.

    1. I’ve spent way too many hours trying to convince people that a 60 step just tempered octave is superior. Major 3rd is horrendously off in the standard 12 tone just tempered octave. 60 tone also allows for supermajor/subminor chords…okay I’ll shut up now

  2. friends don’t let friends use the LM386. Though I suppose it is period appropriate for a 6502. Still, if you’re just using square waves, why not a simple transistor?

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