File Type $D8 (216)
All Auxiliary Types

Full Name: Sampled Sound file
Short Name: Sampled Sound

Written by Matt Deatherage (January 1990)

Files of this type and auxiliary type contain sampled sound data.


Files of type $D8 should contain sampled or digitized sound data. The data is intended to be fed to sound hardware to reproduce a sound that was recorded "live." The converse to "sampled" sound is "synthesized" sound, where a computer creates wave forms and feeds them to sound hardware.

Sampled sound data can be stored in many formats. The data is traditionally sampled in discrete intervals, with a given number of bits used to record the intensity of the sound at the sampling point. In addition to the samples themselves, this requires that the file contain the sampling interval (or rate) and perhaps the number of bits used in sampling. Other information may be needed by applications, such as the duration of the sound, comment or copyright information, compression information or parameters, or "markers" which denote specific points within the sampled sound.

Apple Computer, Inc. presents a standard for such files, the Audio Interchange File Format (Audio IFF), described in another File Type Note. While Audio IFF is suitable for many needs, it cannot hope to cover all. Apple assigns auxiliary types in this file type for such purposes.

Note: Apple does not recognize a standard in which the sampling rate is contained in a file's auxiliary type. Doing so is not possible within the realm of file type and auxiliary type assignment.

The following auxiliary type assignments are current for this file type as of the publication date of this Note:


      Auxiliary Type  Short Name                Developer
      _________________________________________________________________
      $0000           Audio IFF                 Apple
      $0002           ASIF instrument           Apple
      $0003           Sampled Sound Resource    Apple
      $8001           HyperStudio sound         Roger Wagner Publishing
      _________________________________________________________________

                    Table 1 - Auxiliary Type Assignments

The auxiliary types for this file type are reserved; any not listed in this Note or About File Type Notes must be assigned by Apple Computer, Inc. Using any file type or auxiliary type not assigned may result in conflicting identification of files by totally unrelated programs. To obtain an auxiliary type assignment in this file type, see About File Type Notes.

Further Reference


This and all of the other Apple II Technical Notes have been converted to HTML by Aaron Heiss as a public service to the Apple II community, with permission by Apple Computer, Inc. Any and all trademarks, registered and otherwise, are properties of their owners.