Other Digital Audio Devices 613If you do not have a suitable computer, of course, this option is not open to you, and
you will need to look at one of the CD writer units intended to be used along with a hi-fi
system. Such units are more expensive because they need to incorporate several items of
circuitry and software that would be available within the computer. In this chapter, the
termdrive refers to a unit incorporated into, or connected to, a computer, and deck means
a unit that is part of a hi-fi stack or assembly.
Until 1990, the idea of creating your own CDs would have been considered ridiculous
because the creation of a CD involved many processes that called for elaborate and
expensive equipment. The availability of compact disc writing equipment that is well
within a normal domestic budget is due to evolution of CD technology, dispensing with
the need to burn into the disc material. The system that is mainly used for home sound
recording, or for computer use, is CD-R, meaning CD recordable. This system allows you
to write once to a disc and read it as many times as you like. Early versions also allowed
this, but later technology allows you to add more tracks to a disc if you did not fi ll it on
earlier sessions. A disc that permits this type of use is described asmultisession. At the
time of writing, a blank CD-R disc costs around £ 0.75, making this the least expensive
method of recording that has ever been devised. A CD-R disc will hold up to 74 min of
full CD-quality music, or the equivalent in computer data, about 650 Mbytes.
Computers and some more recent hi-fi CD recording decks can also use a different form
of technology, CD-RW, which allows a disc to be recorded, played, wiped, and recorded
again, much like as you reuse a tape or a fl oppy disc. This technology is, at present,
not so well suited to audio use, and although the blank discs that once cost around £ 10
each are down to less than £ 3 each, they are not so popular for computing use either.
Many of the better computer CD writer drives can use either type of disc, and prices are
remarkably low, typically £ 125 if you shop around. Most CD-R drives can write at
2 or 4 , or even 6 , depending on the model, which means that they can make a
recording of existing digital fi les faster than a tape. A 2 recorder will record at twice the
speed at which the music can be played. This is an advantage for the drive in a computer,
because data fi les of music can be processed as fast as the CD writer allows, but for the
CD-writer drive in a hi-fi installation you cannot speed up the music at the input and high
recording speed is pointless. A drive or deck that allows both CD-R and CD-RW discs to
be recorded and replayed is known as a CD-R/RW drive or deck.
Unlike DAT, there are no copyright barriers to CD recording. DAT developed as a medium
for sound recording, and the record industry worked overtime to make sure that the system