Developer diaries

Beeper vs AY: Hear the Difference in Our Seven Games

Every game in our arcade has two soundtracks: beeper on the 48K and AY music on the 128K. Here is how one tape does both, and what each chip can do.

Load any of our games on a 48K Spectrum and you'll hear the beeper. Load the same tape on a 128K and you'll hear full three-channel music. Here's what's going on, and where to listen.

The beeper: one speaker, one bit

The 48K Spectrum's sound is a tiny speaker that the processor switches on and off. To play a note, the program flips it at the right speed; to play two notes at once, it has to flip it in a clever pattern. Anything the processor spends on sound, it can't spend on the game. That's why most 48K games play music on the title screen and only short effects during play, and why ours play their beeper sounds in tiny chunks each frame, so a key press always starts the game at once.

The AY: a sound chip of its own

The 128K's AY-3-8912 has three tone channels and a noise generator, and it plays by itself once it has been told what to do. So the game can update the music fifty times a second and get on with everything else. We used one channel for the melody, one for the bass and one for the drums, building kick drums from falling tones and snares and hi-hats from noise.

One tape, two soundtracks

All seven games share the same music player. When a game starts, it writes two test values to the sound chip and reads them back. If both come back, there's an AY, and the music switches on. If not, the game carries on exactly as it was first written, with the beeper, and never touches the AY again. The 48K versions are unchanged, screen for screen.

Where to listen

GameIn-game AY tuneHow it changes
Apocalypso!Last Dance Before The EndA new key, tempo and beat in every zone
GemquakePickaxe BoogieFive variations as you go deeper
MothfallStarmoth RunEach zone has its own key and beat
Jelly StormJelly MarchRises in key and speeds up wave by wave
Crypt CaperCorridorsA different key and pace on each floor
Buzz BeeBumble BoogieA crash jingle when the bee hits a hedge
The Gullrock LightThe Keeper's LamentPlays over the introduction, then steps aside

Each game's page has a recording of its 128K soundtrack. To hear the beeper versions, switch Speccy to 48K and start the game.

Which is better?

Neither, really. The AY gives you proper arrangements, but the beeper has a raw, buzzy character that many players love, and the best beeper music of the 1980s and since is astonishing for what it is. Our guide to the 48K and 128K explains the rest of the differences, and writing a Spectrum game lists tools for composing for both.

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