26 Reply by utz

  • utz
  • utz
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  • Registered: 2015-06-28
  • Posts: 1,012

Re: 1-bit sound on BBC Micro / Acorn Electron

The noise channel probably won't be useful since it starts on a low cycle.

However https://www.smspower.org/Development/SN76489 claims that

If the register value is zero or one then the output is a constant value of +1. This is often used for sample playback on the SN76489.

so we won't get any more volume range than we already have anyway. Might still be worth a try to see if 0 gives a better range than 1.

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  • Registered: 2021-05-26
  • Posts: 15

Re: 1-bit sound on BBC Micro / Acorn Electron

Unfortunately I don’t hear any difference.  However, I’ve now ported the code to the Acorn Electron which only has an on/off state for sound (no volume control) and I can hear a recognisable tune - it has a slower 1MHz processor so needs some adjustment.  Based on what I’m hearing there may still be some issues with the pattern parsing.  I’ll look through a disassembly of XXL’s Atari Tritone code to see if there’s anything obviously different.