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@@ -7,7 +7,7 @@ /___/_/ /_/\____/\___/___/_/\___/ ``` -This repository contains a single file `Typescript` implementation of General Instrument's [`A-3-8910`](https://en.wikipedia.org/wiki/General_Instrument_AY-3-8910) `PSG` (programmable sound generator) in +This repository contains a single file `Typescript` implementation of General Instrument's [`AY-3-8910`](https://en.wikipedia.org/wiki/General_Instrument_AY-3-8910) `PSG` (programmable sound generator) in less than `1K` lines and without any magic constants! The emulator allows for fine tuning of the `DAC` look-up table though modification of the following variables: @@ -26,6 +26,15 @@ The offical datasheet for the `PSG` can be found [`here`](http://map.grauw.nl/re Sound output is achieved in the browser through an `AudioContext()` hook. <br> This `emulator` also adds interrupt support (with a user defined frequency) for updating the `PSG's` registers. +`AY8910` emulators naturally generate high frequency content which must be suppressed. This is achieved with a FIR low pass filter using a procedurally generated `Blackman-Harris` window. + +The `FIR` response can be changed through modifications of the following constants: + +``` +const FIR_CUTOFF = 2500; // Hz +const FIR_TAPS = 100; // N taps +``` + > Note: `FIR` LPF (Low-Pass Filter) data is generated procedurally. Compile with `tsc emu8910.ts`. |