Ben Eater Creates Audible Computing Sounds
In the world of hacking, when [Ben Eater] speaks, it's a must-listen event. In his latest how-to video, [Ben] enlightens us on generating computer noises using square waves and a 6502 microprocessor.
Utilizing the timer found within the W65C22 Versatile Interface Adapter, [Ben] generates square waves that ultimately produce tones. To support a new command in his MS BASIC interpreter, he adds some clever tweaks. If you're interested in diving deeper into [Ben Eater]'s MS BASIC, you can find our older post on the topic right here on our website.
[Ben] verifies the frequency of oscillation with the help of a Keysight oscilloscope and incorporates an 8Ω 2W speaker with the assistance of a LM386 audio amplifier. The W65C22 output pin is not powerful enough to drive the speaker directly, so [Ben] deftly employs a standard LM386 circuit layout from the datasheet to amplify the signal. The cherry on top? [Ben] pens a program for his BASIC interpreter that plays a melody.
We're grateful to [Mark Stevens] for the heads-up on this! If you're excited to try this out, the best place to start is by building your very own homebrew 6502 system, just like [Ben] did!
Homebrew 6502 Journey
- Purchasing 6502 Chips: You can assemble a computer around a purchased 6502 processor chip by connecting it to RAM, ROM, input/output controllers, and clock circuitry on a breadboard or PCB.
- DIY 6502 Computers: Across the web, creative hobbyists have fabricated easy-to-assemble 6502-based computers with minimal components capable of running BASIC or assembly code.
- Programming in 6502 Assembly or BASIC: Mastering 6502 assembly language and using BASIC interpreters designed for 6502 systems enables you to compose programs that manipulate hardware features such as sound.
Tone Generation in 6502 MS BASIC
- Creating Square Waves: Square waves serve as the simplest digital sound waves, cycling between two amplitude levels. On 6502 systems equipped with simple sound chips (like the SID on the Commodore 64), BASIC commands can generate square wave tones by altering frequency registers or using timer loops.
- MS BASIC Sound Commands: Many MS BASIC versions designed for 6502 machines feature the or commands, which generate square wave tones by specifying frequency and duration.
- Example BASIC Code:
This example linearly increases a tone frequency, eliciting the classic "computer noises" through the manipulation of square wave frequencies.
Summary
- Rolling your own 6502 microprocessor from the ground up is an advanced hardware engineering project, mainly involving CMOS transistor-level design, and such endeavors usually require extensive semiconductor fabrication facilities.
- Homebrew 6502 computers are more accessible when using existing chips and components, with several projects online that guide enthusiasts eager to build their systems.
- By implementing 6502 assembly language or using MS BASIC interpreters tailored for 6502 machines, you gain the ability to create software that generates sound through hardware manipulation, much like vintage 6502 computers.
In the realm of homebrew 6502 computers, one can assemble a system utilizing purchased 6502 processor chips, connecting them to RAM, ROM, input/output controllers, and clock circuitry on a breadboard or PCB. For those interested in generating hardware-based sounds, mastering 6502 assembly language or using BASIC interpreters designed for 6502 systems, like the one demonstrated by Ben Eater, enables creating programs that manipulate hardware features such as sound through square wave tones, as demonstrated in his latest video.
