99 minute blanks

Last change: 19-03-2002

Technical background

This unusual amount of storage capacity is made possible by the combination of the two known methods used so far to raise capacity:

1. Moving the tracks of the Helix closer together, as is done with 80 minutes blanks. 2. Using the so-called method of 'overburning' which uses the full capacity of the media beyond the given specifications, giving you an additional 2 to 4 minutes.

Both methods used together will give you blanks of exceptional length which still have to be 'overburned'. This is due to the fact that the ATIP of the blank, such as 80 minute media, specifies a maximum recording length of 79:59 minutes - regardless of the actual capacity of the blank. Unfortunately it is not possible to extend these specifications much beyond that point. These specifications were agreed upon more than ten years ago when the CD was introduced and they were intended for 74 minute media. Even the now common 80 minute blanks are not really compatible with the original specifications (although they are included in them), and processing them is only possible because of the fact that there is built-in tolerance concerning the distance between tracks. Incidentally, brand name CD-Rs will mostly only work within the given specification to ensure best compatibility with as many recorders and players as possible. This explains why for a long time only no-name 80 minute blanks were available.

Hardware problems with the 99 minute media

Given the extreme exploitation of all existing tolerances you are likely to experience problems when recording or processing 99 minute blanks. Not every drive will happily record information onto the blank. There can, for example, be problems due to the information encoded in the ATIP of the media, where the maximum recording time specified is 79:59 minutes. The space beyond that is reserved for lead-in data. If one wants to use this space for recording data then the space would have to be displayed in negative values. The last sector within the 79:59 minute space would be given the value of 1 and the first sector beyond that would have the value of -45150. This would result in having every sector number within that space twice on your CD. Given this many drives will refuse to record any data into that region of your blank. Some audio CD players and CD-ROM drives will also experience difficulties processing the blanks, especially when trying to start a track. The playback may be delayed by as much as 45 seconds until the player has found the right track. Some players will not play tracks that start beyond the 90 minute mark when the track is directly selected.

Software problems with the 99 minute media

Recording programs get their information about the blank from the ATIP of the media. If the ATIP specifies a maximum time of 80 minutes then the only way to use any space beyond that is the method of so-called 'Overburning' which was until now used in cases where one wanted to sqeeze a little more information onto a 74 minute blank. That means that you need the right software which enables you to 'overburn' blanks. The program will normally display a warning message in these cases. Under certain circumstances the program will not be able to process the blank at all. It will at least display the 'wrong' maximum recording space of the blank because the specified time is 80 minutes. Otherwise all recorders would reject the media. Conclusions Working with both CD-Rs of more than 650 MB and the 'overburning' method requires a compatible recorder as well as the right recording software. In terms of software we recommend CDRWIN from Golden Hawk, DiscJuggler or cdrecord from Jörg Schilling. Should you want to use recording software from other manufacturers, we recommend that you contact themdirectly. A list of compatible drives can be found here:

*1) The CD recorder Teac CD-R 56S/58S will record up to 89:59 minutes when running in Teac 55S compatibility mode.

*2) We generally recommend using 2x speed or at most 4x speed to record or you run the risk that some tracks contain errors. The Ricoh MP 9060 drive for example will often fail to record successfully when using 6x speed!

Please note: This list is not meant to be conclusive in any way. We are in contact with many different manufacturers of CD recorders and most of them are interested in compatibility. We will try to give you first-hand information about any improvements done by the manufacturers in terms of compatibility!