SOUND CHECK NEWS:

Finaly caught some spare time to make some more sound tests
My new studies indicate that Kinpo engeneers were not so bad after all -namely they implemented old concept of wireing speaker to timer output.
This technique is very old, used in IBM PC's but is present in nowdays PC's as well.
Until now we had to trigger the speaker PIN by software to produce sound. Using timer tecnique we can simply set the frequency and enable the timer -sound will be produced directly by hardware (almost by itself) At the same time processor will be free for other work.

The tests i did with application/operating system revealed that Kinpo OS actualy produces sounds this way, (key-click sounds), however Saturn Emulator seems like it produces sounds the "old-fashion" way.

Current SOUND CHECK is like "software" version. Using timer in PWM (pulse width modulation) mode sound routine will be a lot simpler, and more precise.
Of course the use of timer will simplify the code -that would be like "hardware accelerated"

In practice i was able to reprogramm speaker PIN, enable TIMER2 of the ARM processor and sucessfuly controll the sound.

Mainly because it is uncomatible with older 49G, but as you will see sound works on G+ as well, with just a little different approach sampled sounds are possible.
Current 'SOUND CHECK' plays 8 bit unsigned PCM samples at 13.4 kHz (ksps)

Small music loop is embeded in the library for those who will not have the time to produce their own sample, but will still be interested in how it sounds like.

Since OPENFIRE is getting popular and being updated on everyday basis, it is clear that sound features should be supported.
Therefore a substitute for OUT=C (which was used for speaker control in Saturn assembly)
INITPF command has now embedded OUT=C substitute, for more details see INITPF command details.

Quality considerations:
The speaker used in the G+ is piezo beeper
-same as ones used in 48 series, this is one of the reasons why
sound is "hard"

Maybe RC filter could make the sound more natural, but the real improovement would be to exchange piezo-beeper with miniature dynamic speaker.
NOTE: polyphonic cell phones use miniature dynamic speakers to produce melodies rather then piezo-beepers.

Terms and contitions
OPENFIRE is to be used and distributed freely
as long as you don't modify the library code.

Beware
-although library is stable and doesn't cause memory issues
i DON'T PROVIDE any WARRANTY or GUARANTY.
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  • SOUND CHECK
       -introduces sampled sound capabilities to G+
       -8x oversampling added, plays your samples
        read the ABOUT included in library (updated:10/16/2004)
    		• These are demo samples to be used with
    SOUND CHECK library.
    Put the file (string) on the stack and start PLAY in soundcheck library.

    These are RAW 8 bit unsigned samples 13400 Hz, dynamics must be limited for best results.
    sample1
    Beavis (MTV) monologue
    sample2
    Madonna
    sample3
    ShutDown
    sample4
    Toni Espozito
    sample5
    Zoolookologie