Friday, April 29, 2011

FTP server address change

The FTP server can now be reached at ftp://sqrmax.dyndns.org. Enjoy!

Friday, April 01, 2011

6581 SID, the gift that keeps on giving

A SID chip, famously used for sound on the C64, has 3 synthetized voices. The older 6581 chips had a number of design defects because there was no time to finalize the implementation. For example, the filter didn't work right, and the output had DC bias because of electronic issues. However, these problems allowed people to hack the 6581 SID to no end. Here's an example, achieved about 25 years after the C64 was introduced. On a C64, you can have:

  • 4 channels of 8 bit sampled digital output,
  • 2 channels of SID sound,
  • have the filter apply to the sampled output as well,
  • and still have enough CPU time to do your own stuff.
This page here has this link to an mp3 file that has been taken off from a C64. At first you do not think much of it, but the C64 I know *never* sounded like that... the mp3 sounds like it belongs to an Amiga instead!