Merge pull request #4 from ramapcsx2/patch-1
Added confirmation about the wasted 32k CD buffer
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@ -1820,6 +1820,28 @@ before the cdrom controller receives and skips further sectors). Otherwise
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sectors would be lost without notice (there appear to be absolutely no overrun
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status flags, nor overrun error interrupts).<br/>
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#### Update:
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This is confirmed, as found in the SCEA_BBS.pdf bulletin board archive:
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```
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12/29/95 10:24 AM
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Re(4): CD buffer
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Thomas Boyd
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CD
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Dan Burnash
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OK. This is the story of the CD ROM subsystem sector buffer:
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The CD-ROM subsystem sector buffer is currently 32K. It is located in the CD-ROM subsystem.
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It uses a sort-of tripple buffering system to read sectors in and make one (and ONLY one) sector
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available to the user.
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Common questions that spring to mind and their answers:
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Q: 32K - (2352 bytes/sector)*(3 buffered sectors) = lots of leftover RAM! Can I use it? A: No. It is
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not accessible by anything but the CD-ROM subsystem.
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Q: How dissappointing. As consolation, can I be told what the extra memory is used for? A: The
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memory was going to be used for sound mapping, but (1) the system would be too slow, and
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(2) sound mapping is already done by the SPU. The current implementation of this memory is ...
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nothing. It is vestigal and will be cut out in future manufacturing cost reduction designs.
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Tom
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```
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#### Sector Buffer Test Cases
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```
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Setloc(0:2:0)+Read
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