Sample bank

A Sample bank holds a table of 8-bit signed mono PCM samples, each with an 8-character ASCII name and a playback frequency in Hz. Used by AMOS with the SAMPLE PLAY command.

Samples are always stored in chip RAM.

Commands

# Export to JSON + WAV files
portamos disasm Samples.Abk output/samples.json

# Export with IFF 8SVX audio instead of WAV
portamos disasm --8svx Samples.Abk output/samples.json

# Name audio files after sample names rather than index
portamos disasm --sample-names Samples.Abk output/samples.json

# Reassemble
portamos asm output/samples.json Samples.Abk

JSON schema

{
  "type": "Samples",
  "bankNumber": 5,
  "chipRam": true,
  "samples": [
    {
      "name": "BanjoSyn",
      // playbackRate omitted — read from the audio file's sample rate
      "file": "samples-sample000.wav"
    },
    {
      "name": "LAAA",
      "playbackRate": 14563, // override when the audio file's rate doesn't match
      "file": "samples-sample003.wav"
    },
    {
      "name": "Empty"
      // no "file" key — empty slot
    }
  ]
}

Field	Type	Description
type	string	Always "Samples"
bankNumber	integer	Bank slot (1-based)
chipRam	boolean	Always true for sample banks
samples[].name	string	Up to 8 ASCII characters
samples[].playbackRate	integer	The rate at which AMOS plays back the sample, in Hz. If omitted or set to 0, read from the audio file’s sample rate metadata.
samples[].file	string	Path to audio file relative to the JSON; omit for empty slots

Audio files

Samples are exported as RIFF WAV (8-bit unsigned PCM) by default, or as IFF 8SVX (8-bit signed PCM) with --8svx. On import, both WAV and 8SVX are accepted and converted automatically.

WAV 8-bit audio is unsigned. Portamos converts to/from the signed format AMOS uses automatically — you do not need to account for this when editing samples in an audio editor.