Many people feel that the current media size (74 and 80mins CDs) not enough for them. Recently 90 and 99mins CDs come out. The news made many users happy since they now could burn much more data in them. We decided to test the new 99mins media and see if check possible problems using them.
- Most current CDR-W drives are NOT able to write up to 99min media. Why?
The "disk length" that CD writers see is stored in a pre-made readable area of the disk known as ATIP (absolute time in pre-groove, literally). In ATIP, due to bad design on the part of the writers of the Orange Book, the maximum value that can be placed here is 79:59:74. This means that it is not possible for normal CD writers to know if a 99 minute disk is inserted. As a result, the only way to burn 99 minutes is to overburn.
The "standard" calculation for converting between sector numbers and MSFs causes problems with large disks. In the original CD-ROM standard, it was defined that MSF times of 90 minutes and above were to be considered negative. That is, 99:59:74 (sector -151) comes immediately before 00:00:00 (sector -150). The reason for this is to give MSF addresses to sectors in the lead-in area. However, it causes problems because now you have 2 places with the same address.
90:00:00 can either mean a really negative address, or 90 minutes into the data portion of the disk. When a drive sees 90:00:00, it won't know how to handle it, and it will screw up. Theoretically, the maximum CD-ROM disk size is 159:59:74. However, we'll never see that unless these problems are fixed.
- How they did manage to fit 99mins in one CD and keep the original size?
They did as with 80mins (moving the tracks of the Helix closer together). As we said earlier you must also use 'overburning' which uses the full capacity of the media beyond the given specifications, giving you an additional 2 to 4 minutes.
- Who makes 99min CDs?
Unknown..for now. We had posted in June2000 that TraxData would ship 99min media. But the media we got comes from other manufacturer which no program regongized. All programs (CDR Intentifier, Plextor CDRINFO, Feurio) gave back only the manufacturer code: 97 35 44. Here are more info from CDR Intentifier:
ATIP: 97m 35s 44f
Disc Manufacturer: Disc ID not allowed
Assumed Dye type: Disc ID not allowed (Type 4)
Media type: CD-Recordable
Recording Speeds: min. unknown - max. unknown
Nominal Capacity: 702.83MB (79m 59s 74f / LBA: 359849)
- How much space can a 99min CD hold?
You should expect around 870mbs for data and 995 for audio.