Well, it may well be argued that 80-minute is out of spec with the 1982-ish Red Book, but in 
practice commercial CDs of more than 74 minutes have been released on a somewhat frequent basis 
since at least the late 1980's. So, by the time CDR media became available to the masses, any 
respectable player that could read a CDR in the first place should have no more trouble with a 
80-minute vs. a 74-minute. I did say respectable player, as I've had cheapo portables and early 
automobile players that had trouble with 80-minute media.

Mike, when you say "we know that they have higher error rates and are harder to read than equivalent 
74s," can you explain how we know this? How many different tests at different times by different 
people are you citing as evidence? Also, are these results several years old or recent (or both), 
and comparing 74- and 80-minute products of the same dye types and same manufacturers at the same 
time? Not picking on your assertion, just trying to find out how scientifically rigorous this 
widely-bandied assertion about 80-minute media is.

Finally, the error rates detected, how did they compare with random samples of commercially-produced 
music CD's?

-- Tom Fine

----- Original Message ----- 
From: "Mike Richter" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, January 04, 2008 8:28 PM
Subject: Re: [ARSCLIST] CD-R question


> Tom Fine wrote:
>> So then no one really knows if 80's are less reliable? If this "reliability" issue is mythology, 
>> why is so common on this forum? I ask because 650 meg media is becoming somewhat rare and oftem 
>> much more costly. If there is no proven advantage then it is silly to insist on it, as some 
>> clients do.
>
> No. We know that they have higher error rates and are harder to read than equivalent 74s. We know 
> that high error rates and poor readability typically precede failure in typical discs. But I know 
> of no stronger reason to believe that 80s are less reliable than 74s.
>
> To save a separate thread, some notes may be in order on the standard lengths. The standard for 
> pitch on the spiral of a CD leads to 74 minutes' recording time. Manufacturing tolerances being 
> what they were two decades back, tolerance on the pitch demanded that the player handle pitches 
> corresponding to 63 through 80 minutes. More than a decade ago, TDK offered an 80-minute CD-R at 
> prohibitive cost; it lasted some time in the catalogue, but was unavailable in practice.
>
> Any longer blank is out of spec. Indeed, it may be argued that any over 74 minutes is out of spec.
>
> Mike
> -- 
> [log in to unmask]
> http://www.mrichter.com/
>