beeeepp!

By PingPong

Prophet (3459)

PingPong's picture

02-01-2017, 20:50

hi, all and good year.
Does some one know how msx beep generate the sound? i know it drive the sound port via cpu, but where it get the data from for the various 'kind' of beep tones?
thx. in advance

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By Louthrax

Prophet (2093)

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02-01-2017, 21:27

That's a good question. With some luck the sound is produded in an "atomic" CPU loop (not using interruptions). Just use openMSX and break into the code when the beep is playing (using one of the "long" beep version) ?

By ARTRAG

Enlighted (6273)

ARTRAG's picture

02-01-2017, 22:25

Put a break point at 0xc0 and follow the code when a beep is executed

By gdx

Prophet (3075)

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03-01-2017, 12:25

The Beep and the click sound of keys are produced by PPI.

By hit9918

Prophet (2868)

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05-01-2017, 08:56

but, when you say sound 8,8 then it makes the same tone as beep.
so the beep was made by AY.

By hit9918

Prophet (2868)

hit9918's picture

05-01-2017, 09:02

a beep with the keyboard click I would expect to be louder, full amplitude like sound 8,15.
and when after sound 8,8 you press CTRL-G, then it sounds like "simply off".
a beep happened but it sounded no different than sound 8,8, the impression is "simply off".
it's these indications that make me assume AY without further looking.

By zeilemaker54

Master (249)

zeilemaker54's picture

05-01-2017, 11:29

Beep is generated by the PSG for sure.
See my MSXSYSSRC project:
MSX1:
https://sourceforge.net/p/msxsyssrc/git/ci/master/tree/base1..., beep is on A1113
MSX2:
https://sourceforge.net/p/msxsyssrc/git/ci/master/tree/base2..., beep is on J1A62

By gdx

Prophet (3075)

gdx's picture

05-01-2017, 12:23

You are right.

By zeilemaker54

Master (249)

zeilemaker54's picture

05-01-2017, 15:09

zeilemaker54 wrote:

Beep is generated by the PSG for sure.
See my MSXSYSSRC project:
MSX1:
https://sourceforge.net/p/msxsyssrc/git/ci/master/tree/base1..., beep is on A1113
MSX2:
https://sourceforge.net/p/msxsyssrc/git/ci/master/tree/base2..., beep is on J1A62

Turbo-R version is better commented:
https://sourceforge.net/p/msxsyssrc/git/ci/master/tree/base4..., beep is on J1B58

By witchspace

Supporter (5)

witchspace's picture

01-02-2017, 07:53

Those disassembled ROM listings are nice, incredible work zeilemaker54.