The following came in via Rainer on the SDIY list:"On the SID, samples are played back through 3 different methods:
(1) 4-bit playback abusing the volume register
(2) 8/12-bit playback using PWM (with nasty carrier beep-through...)
(3) stepping the triangle waveform using test bit (reset) and
incrementum (reaching the destination value within 1 sample)
The latter is a rather novel technique first presented in the "Vicious SID" and "Fanta in Space" demos, also demonstrating how this technique even outperforms the Amiga's sound capabilities (by being able to fully modulate the sample using ADSR, multimode filter, and final VCA -- plus having two SID voices in addition to the sample).
For those interested:
Vicious SID:
http://noname.c64.org/csdb/release/?id=72678
Fanta in Space:
http://noname.c64.org/csdb/release/?id=72563
If you run them on the VICE emulator, make sure to switch the reSID engine to floating point, otherwise you won't hear much...
Rainer"
No comments:
Post a Comment
Note: comments that insult people will be removed. Critique on gear is allowed. Do not ask if listings are still available. Click through auction links to check yourself. Posts and pics remain for historical purposes. To reduce spam, comments for posts older than one week are not displayed until approved (usually same day).