CD-R sizes?

[Kalle]

When I went to buy new CD-R's the other day I decided to go with the more expensive 90 min/800 MB storage discs, figuring a little extra diskspace wouldn't hurt, but today when I wanted to use one it shows up in windows as only having 702 MB of free space. What's up with this, have I been ripped off?

[Sean Tudor]

Maybe it is only supported by certain CDR drives ?

[Lunch of Kong]

What's up with this, have I been ripped off?

Perhaps. Did the label on the CD-R package warn you that you need a special CD-R drive to write and read them? If not, you may be able to return it to the shop.

90 minute/790 MB and 99 minute/870 MB CD-R media do not conform to Orange book standards, and not all drives support them.

Additionally, some drives that can burn this high-capacity media can only do so at 1x or 2x.

For a 90 min CD-R compatibility chart, see:
http://shop.store.yahoo.com/cdrdvdrmedia/90mincdr1.html

[Midnight Son]

http://www.hitek.com.au/90inst.htm


This unusually sized CDR is made possible by moving the tracks of the Helix closer together (as is done with 80 minute blanks). It also employs the so-called method of 'overburning' which allows the media to be stretched to 90 minutes.

When a 90 minute CDR is inserted, it will pick up as an 80 minute CDR, and you have to 'overburn' this to 89:59 (many burners are unable to go past this limit) to use the full capacity. If your burner is unable to overburn, there is NO way of using 90 minute CDR (see list below).

You maybe wondering why a 90 minute CDR doesn't simply pick up as 90 minutes, reducing all the hassle involved with overburning. Well, the International Standard says the maximum size of a CDR can only be 79:59 minutes (80 min), thus the only way to override this is to use the concept of 'overburning'.

Software capable of 90 minute overburning include:
Nero 5.0.3.8
CDRWIN 3.8C
WinOnCD 3.8 Power Edition
DiscJuggler 3.00.758
Feurio 1.52
(click the above links to see 'how to' use 90mins in each software title)

You must write in 'Disc-at-Once' (DAO) mode in order to overburn (which is usually default anyway). Different software need different settings to enable you to commence overburning, so consult the Help file. Older versions of the above software may also work.

* Remember that 90 minute CDR are readable on 'all' drives *