Difference between revisions of "Hanging note bug"

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(Added info about DSP relevance. Moved some model numbers from "Bug-free" to "Bugged".)
(Almost complete rewrite.)
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The so-called ''hanging note bug'' is a bug present on certain models of the [[Creative Sound Blaster]] series. Affected are models with DSP revisions 4.11, 4.12 and 4.13. It can only occur when the card is utilized simultaneously for sound effects and wavetable MIDI music either with external modules or Wave Blaster daughterboards.
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The so-called ''hanging note bug'' is a hardware bug on certain models of the Creative [[Sound Blaster 16]] and [[Sound Blaster AWE32]] series of sound cards. The bug only occurs when affected cards are utilized for digital sound effects and MIDI music simultaneously, but it happens on any MIDI device regardless if connected to the internal [[Wave Blaster connector]] or externally through the game port.
  
== Cause ==
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== Type 1: Illegitimate hanging notes ==
...?
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This variant of the bug happens in games which use the ''DMX sound system'' programmed by Paul Radek:
 +
*Doom
 +
*Doom2
 +
*Heretic
 +
*Hexen
 +
*Raptor
 +
*Hocus Pocus
 +
It manifests itself as MIDI notes being generated randomly. Since these notes are not part of the soundtrack, they are not stopped and hang for a long time. Also, these 'illegitimate' notes tend to be high-pitched, which makes this variant of the bug a rather annoying experience.
  
== How to find out if a card is affected ==
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== Type 2: Legitimate hanging notes ==
*Start [[Hexen]] with '''hexen -warp 02'''. You will notice hanging notes almost immediately.
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This type of the bug has been witnessed in many games, but occurs very rarely. In this case, the hanging notes are part of the soundtrack, but for some reason the "Note off" command is missed.  
*...?
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== Sound card model numbers ==
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== Affected cards ==
=== Bugged ===
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Affected are all Sound Blaster models with DSP revisions 4.11, 4.12 and 4.13.
*CT1740 (DSP 4.12)
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*CT1750
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*CT1770
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*CT2230
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*CT2260
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*CT2760
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*CT2800
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*CT2860
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*CT2910
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*CT2940
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*CT2950
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*CT2980
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*CT3600
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*CT3900
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*CT3980
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*CT3990
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=== Bug-free ===
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Type 1 doesn't occur on cards with a CT1747 bus interface (CT2230, CT2760, CT3900, CT3980).
*CT1730
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Type 2 has been reported to happen on cards with DSP 4.16 (AWE64) as well.
*CT1740 (except DSP 4.12)
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*All AWE64 cards (DSP 4.16)
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== Cause ==
 +
...?
  
 
== External links ==
 
== External links ==
 
[http://vogons.zetafleet.com/viewtopic.php?t=20849 Related thread on the VOGONS forums]
 
[http://vogons.zetafleet.com/viewtopic.php?t=20849 Related thread on the VOGONS forums]

Revision as of 10:46, 3 March 2013

The so-called hanging note bug is a hardware bug on certain models of the Creative Sound Blaster 16 and Sound Blaster AWE32 series of sound cards. The bug only occurs when affected cards are utilized for digital sound effects and MIDI music simultaneously, but it happens on any MIDI device regardless if connected to the internal Wave Blaster connector or externally through the game port.

Type 1: Illegitimate hanging notes

This variant of the bug happens in games which use the DMX sound system programmed by Paul Radek:

  • Doom
  • Doom2
  • Heretic
  • Hexen
  • Raptor
  • Hocus Pocus

It manifests itself as MIDI notes being generated randomly. Since these notes are not part of the soundtrack, they are not stopped and hang for a long time. Also, these 'illegitimate' notes tend to be high-pitched, which makes this variant of the bug a rather annoying experience.

Type 2: Legitimate hanging notes

This type of the bug has been witnessed in many games, but occurs very rarely. In this case, the hanging notes are part of the soundtrack, but for some reason the "Note off" command is missed.

Affected cards

Affected are all Sound Blaster models with DSP revisions 4.11, 4.12 and 4.13.

Type 1 doesn't occur on cards with a CT1747 bus interface (CT2230, CT2760, CT3900, CT3980). Type 2 has been reported to happen on cards with DSP 4.16 (AWE64) as well.

Cause

...?

External links

Related thread on the VOGONS forums