Changes

One version called "[[8k Speedlock]]", relied on the fact that the CPC's hardware (specifically, the µPD765 disk controller) could reliably read but not write 8k 8 Kbyte sectorseven though it was typically only possible to store more than 6,250 bytes on 300 rpm double density diskettes. Attempting to write an 8 Kbyte sector would cause the system to over-write its header block.

It was written here that "the format was either devised or done on an Atari ST or an IBM PC compatible machine (since the CPC share with them the same FDC controler). The main difference being that an ST or PC can write more data per track than a CPC." This contains several inaccuracies. The Speedlock team in fact wrote the diskettes using diskette interfaces custom-modified for this purpose. Also, an Atari ST also has 6,250 bytes/track although used a WD1772 disk controller, while the PC has over time been based on a variety of formats (e.g. HD was 360 rpm 15 sectors etc.) and controllers (e.g. NEC µPD765 or Intel 8272A or 82072A.

Another statement written here was: "In itself, a speedlock 'Speedlock track ' exists in 2 versions, used at the discretion of the duplicator, one use a CRC, and the other not." This is inaccurate, in the sense that it was never at the discretion of the duplicator. There were at least two separate versions, one of which may have involved a CRA issue.

A speedlock 'Speedlock track consist ' consists of only 512 byte bytes declared for the sector, and while all the remaining data is spanned in a huge GAP section.When copied on a CPC, the FDC only store stores the 512 first bytes as declared in the CHRN, and discard discards the remaining contained in the gap section. Those tracks have an EDC (Error Data Checksum), because only 512 bytes are used to calculate the data checksum, as well as an illegal data field size. Several other protection mechanisms existed on such tracks, including special codes written by the Trace 1006 duplication equipment commonly in use at the time: these codes could not be written by standard Amstrad disc drives.

There were two Various methods were attempted to get around circumvent thisprotection, including:

2. Executioner's utility Xexor included a 'brain file' solution to crack individual games before copying them. <br>