8k Speedlock - Revision history

Nich: Fixed link to µPD765 page

2022-02-15T10:50:26Z

Fixed link to µPD765 page

Sam-can: Fixed language, added supplemental information

2022-02-13T05:58:07Z

Fixed language, added supplemental information

Polluks at 14:36, 16 September 2015

2015-09-16T14:36:01Z

MacDeath at 23:44, 16 December 2010

2010-12-16T23:44:39Z

Arnoldemu: Created page with "Speedlock is a tape and disc copy protection solution. 8K Speedlock refers to a specific version of the Speedlock where most of the data was stored on special tracks. Each trac..."

2010-08-11T13:30:38Z

Created page with "Speedlock is a tape and disc copy protection solution. 8K Speedlock refers to a specific version of the Speedlock where most of the data was stored on special tracks. Each trac..."

New page

Speedlock is a tape and disc copy protection solution.

8K Speedlock refers to a specific version of the Speedlock where most of the data was stored on special tracks.

Each track was setup with NEC765 sector size 6, which indicated a sector with 8192 (&2000) bytes of data. However in reality, only 6146 (&1800) bytes were useable.
Recreating this format on the Amstrad was difficult because the NEC765 would really try to write 8192 bytes of data, and in doing so it would corrupt the MFM data structure used to layout the sectors on the track.

@@ Line 1: / Line 1: @@
 Speedlock is a tape and disc copy protection solution.
-'8K Speedlock' refers to a specific version of the Speedlock where most of the data was stored on specially formatted tracks. Each track was setup with [[µPD765]] sector size 6, which indicated a sector with 8,192 (&2000) bytes of data. However in reality, only 6,146 (&1800) bytes were useable. Recreating this format on the Amstrad was difficult because the µPD765 would try to write 8,192 bytes of data, and in doing so it would wrap around on itself and corrupt the sector data header thereby making it impossible to read.
+'8K Speedlock' refers to a specific version of the Speedlock where most of the data was stored on specially formatted tracks. Each track was setup with [[765 FDC|µPD765]] sector size 6, which indicated a sector with 8,192 (&2000) bytes of data. However in reality, only 6,146 (&1800) bytes were useable. Recreating this format on the Amstrad was difficult because the µPD765 would try to write 8,192 bytes of data, and in doing so it would wrap around on itself and corrupt the sector data header thereby making it impossible to read.
 Internally the format was known as "Indy", a reference to the fact that it was necessary to synchronize data writing with the index hole and use special hardware to avoid the wrap around. This synchronization was deliberately not maintained during duplication, thereby enabling data to load more quickly.
 [[Category:Copy Protection]]

@@ Line 1: / Line 1: @@
 Speedlock is a tape and disc copy protection solution.
-K Speedlock refers to a specific version of the Speedlock where most of the data was stored on special tracks.
+'8K Speedlock' refers to a specific version of the Speedlock where most of the data was stored on specially formatted tracks. Each track was setup with [[µPD765]] sector size 6, which indicated a sector with 8,192 (&2000) bytes of data. However in reality, only 6,146 (&1800) bytes were useable. Recreating this format on the Amstrad was difficult because the µPD765 would try to write 8,192 bytes of data, and in doing so it would wrap around on itself and corrupt the sector data header thereby making it impossible to read.
-Each track was setup with [[NEC765]] sector size 6, which indicated a sector with 8192 (&2000) bytes of data. However in reality, only 6146 (&1800) bytes were useable.
+Internally the format was known as "Indy", a reference to the fact that it was necessary to synchronize data writing with the index hole and use special hardware to avoid the wrap around. This synchronization was deliberately not maintained during duplication, thereby enabling data to load more quickly.
-Recreating this format on the Amstrad was difficult because the NEC765 would really try to write 8192 bytes of data, and in doing so it would corrupt the MFM data structure used to layout the sectors on the track.
 [[Category:Copy Protection]]

← Older revision		Revision as of 23:44, 16 December 2010
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	Each track was setup with NEC765 sector size 6, which indicated a sector with 8192 (&2000) bytes of data. However in reality, only 6146 (&1800) bytes were useable.		Each track was setup with NEC765 sector size 6, which indicated a sector with 8192 (&2000) bytes of data. However in reality, only 6146 (&1800) bytes were useable.
	Recreating this format on the Amstrad was difficult because the NEC765 would really try to write 8192 bytes of data, and in doing so it would corrupt the MFM data structure used to layout the sectors on the track.		Recreating this format on the Amstrad was difficult because the NEC765 would really try to write 8192 bytes of data, and in doing so it would corrupt the MFM data structure used to layout the sectors on the track.
		+
		+	[[Category:Copy Protection]]