Work-In-Progress Reports for February 2002

28 February 2002

Region Specific Writing, New Descriptors: Region Specific Writing Support for different writing density on PAL/NTSC machines. Descriptors for Amiga * Early Psygnosis games (Deep Space, Brataccas) * Elite * Deuteros * ...and because of the above, quite possibly other games as well. (more)

27 February 2002

One of the Greatest Mysteries of Amiga Hardware Solved!: Something that has bothered us about the Amiga hardware for a long time has now been finally solved. All this information has been passed to Toni of the WinUAE development team, and is now available here to anybody else that can use it. Thanks to Hidehiko Ogata who's system information and dumps helped solve this mystery. (more)

25 February 2002

Analyser Data Recovery: While interrogating many dumps we have found that the analyser seems to recover a surprising number of bad disks! Now that the headers score properly the analyser is able to restore data for many erroneous disks back to 100% correctness. Due to the obvious advantages this has, we have decided to check this in practice. (more)

24 February 2002

Data Integrity and Commodore Documentation Errors: New Added automatic support for checksum dependencies/nested checksums, i.e. checksums that must be calculated in a specific order to give the correct result. This feature is used by mixed format data blocks, such as an AmigaDOS block containing an Atari block. AmigaDOS style parities are now supported. (more)

22 February 2002

A Working Analyser!: The analyser now works! However it is far from complete... Still to do: * The checking of parities/CRC's etc - which would greatly improve detection. * Gap byte detection - gap tracks and block gaps are not detected. * The system needs some routines to balance the scores properly, some of them are quite tricky, however most of the slave work is done and working. (more)

20 February 2002

Improved Track Decoding: Today the track-decoding handler was improved, since it would have been too slow for the increasing number of known disk format descriptors. The old handler would have eaten tens of megabytes for one track and we would have ultra-slow execution caused by the frequent allocation/de-allocation of memory. (more)

19 February 2002

Enhanced Gap-Mastering Support: Different systems and disk drives may each give a slightly different writing capacity and so special gap "indicators" are put on the tracks by the mastering equipment to compensate for these different track lengths. The gap support in our analyser changed slightly to compensate for this and it makes sense that our mastering software should test the writing capacity. (more)

15 February 2002

Finished Sync Scan Caching: First a little refresh... As we described in the last WIP update, once a protection has been reverse engineered and the information obtained has been fed into the analyser using our "disk structure description language", any other game that uses this protection is automatically detected. (more)

6 February 2002

The Analyser: The disk image analyser work is going very well. The disk format description framework is complete, and it allows us to describe each part of a disk. Basically: * The Format descriptor: Description of a whole track. * The Block descriptor: Description of a block. * The Data descriptor: Description of a data element of a block. (more)