previous page: 7-13] What's this about a Canadian CD-R tax?
page up: CD-Recordable FAQ
next page: 7-15] Where can I find CD-ROM business cards and "shaped" CDs?

7-14] Can I get 80mm (3-inch "cd single") CD-Rs?


This article is from the CD-Recordable FAQ, by Andy McFadden (fadden@fadden.com) with numerous contributions by others.

7-14] Can I get 80mm (3-inch "cd single") CD-Rs?


The 80mm CD didn't catch on everywhere. In some markets, notably the USA,
pressed "CD single" discs are rarely seen. The 80mm CD-R made a brief
appearance, and then vanished for a while. As of the middle of the year
2000, they were once again easy to find. In mid-2001, Sony started
using them in one of their Mavica camera models, and towards the end of
2001 80mm-based MP3 players appeared. They're pretty easy to find now.

Using them is not as straightforward as could be hoped. Most *software*
will work just fine, because all CD-Rs have slightly different capacities,
especially when you consider 63-minute, 74-minute, and 80-minute blanks.
The problems stem from their physical dimensions.

Pretty much all tray-based recorders have grooves for 120mm discs and
80mm discs. However, not all of them can actually record 80mm discs.
Web sites for recent drives will sometimes indicate whether or not they're
compatible. Some CD recorders can read the discs but not write them,
possibly because the clamping mechanism raises the disc to a level where
it's no longer sufficiently supported at the edges.

If you have a caddy-based recorder, you will have a problem: while trays
have two different rings for 80mm and 120mm discs, caddies don't.
According to the Yamaha CDR-102 manual, there is a "Disk Adaptor",
referenced as part #ADP08, that sits in the caddy and keeps the disc
properly positioned. A device that performed a similar function used to be
sold by music stores so that standard players could handle 80mm
CD-singles; it looks like a plastic doughnut that clips onto the disc.

If you have one of these, great. If you don't, you may have difficulty
finding them. You will likely have even worse luck figuring out how to
play an 80mm disc on a "slot in" CD-ROM drive -- the kind where you push
the disc into a slot, and it slurps it up. Some manufacturers have
indicated that their traction-feed drives work fine with 80mm discs, but
before you try it might be wise to have a screwdriver handy.

A less common issue with 80mm discs has to do with playback. A loose sheet
included with the CDR-100/102 "CD Expert" manual states:

"An 8-cm disc recorded at normal speed on the CD Expert may not playback
correctly on some manufacturer's CD-ROM drives. This is likely on drives
that have a playback PLL (phase lock loop) bandwidth of 1.5 kHz. Most
drives, however, have a playback PLL bandwidth of 2.5 kHz, in which case
this is not a problem."

The final discouragement for 80mm discs is that they only hold 21 minutes
of audio (about 95250 sectors on Ritek silver-blue discs, or about 186MB),
but at present cost more than their full-sized counterparts. They are an
interesting curiosity, and a cute gift when placed in a miniature jewel
case, but little more. There appear to be 80mm discs that hold 34 minutes
(just shy of 300MB), but these come with the same caveats as 90-minute
120mm discs: the discs have to be constructed at or outside the limits of
what the specifications allow, and you may have problems with compatibility.

[ On a personal note: my Plextor 8/20 refuses to accept 80mm discs when I
put them in the tray. I was able to use them with a (caddy-load) Yamaha
CDR-102 when I put the discs in a CD-single caddy adapter. It turns out
that the Plextor 8/20 will write to the discs when the caddy adapter is
used for it as well. There seems to be some problem with the Plextor's
mechanics when the disc is resting in the 80mm tray. I don't know of a
source for the adapters, though I'm told http://www.cddigitalcard.com/
carries them. ]


Continue to:

previous page: 7-13] What's this about a Canadian CD-R tax?
page up: CD-Recordable FAQ
next page: 7-15] Where can I find CD-ROM business cards and "shaped" CDs?