Speaker references
Surprisingly still relevant...part of the original PC and still in literally every PC since. Not all have an actual speaker, but all have the hardware.
Surprisingly still relevant...part of the original PC and still in literally every PC since. Not all have an actual speaker, but all have the hardware.
Some PC speaker links
http://courses.ece.illinois.edu/ece390/books/labmanual/io-devices-timer.html
http://www.dcc.unicamp.br/~celio/mc404s2-03/8253timer.html (pretty much same as above)
http://www.osdever.net/documents/8253.pdf
http://en.wikipedia.org/wiki/Intel_8253 Wiki on the chip itself
Links on RTTTL (text based ring tones)
http://www.mobilefish.com/tutorials/rtttl/rtttl_quickguide_specification.html
http://www.activexperts.com/xmstoolkit/sms/rtttl/
http://en.wikipedia.org/wiki/Ring_Tone_Transfer_Language
http://ez4mobile.com/nokiatone/rtttf.htm
http://midi.mathewvp.com/rttl2Midi.php
Not exactly speaker, but ...
Pentium time stamp counter http://www.cs.wm.edu/~kearns/001lab.d/rdtsc.html