M-AUDIO DMAN - Manual (Page 8)

8
PnP Theory of Operation
Think of PnP as digital aspirin. Device configuration occurs
transparently in an all-PnP environment. At bootup, the BIOS and
the operating system detect changes and attempt to allocate
resources, eliminating the need to manually configure resources
such as IRQ lines, DMA channels, I/O ports and memory space.
Peripheral adapter cards are put to "sleep" and are then
individually queried regarding which resources are
programmable and over what ranges they may be programmed.
The PnP BIOS will then build a conflict-free resource assignment
list for all PnP devices, update a stored working-configuration
database, activate the peripheral devices, then start the operating
system (Windows 95 for example) which loads the device drivers
with the provided configuration information.
About Digital Recording
If you've only done analog recording before, you're in for a treat.
If you have done digital recording before, you can skip over this
section (our feelings won't be hurt).
As taught in high school science class, sound is composed of
waves of changing pressure (level) and frequency (pitch). Analog
recording captures these waves in their entirety and records them
as variations in magnetic flux (tape) or variations in depth (good
old fashioned vinyl). On playback, analog recording adds noise
to the recorded sound at relatively high levels (tape has
background hiss, vinyl has surface noise); it therefore causes a
low signal-to-noise (S/N) ratio. Because this noise level is
comparatively high, the dynamic range (soft to loud) of the
recording is decreased.
On the other hand, digital recording samples the sound waves
(typically 44,100 times per second or at a rate of 44.1 kHz) and
records the sounds as digital data. This numeric data can be
stored on a hard or floppy disk, DAT tape, CD, or any other
common data storage media. During digital playback, no noise is
added by the recording medium. This results in a much greater
S/N ratio and greatly increased dynamic range over analog
methods. The end result is cleaner, quieter recordings. The only
noise present in the digital realm is any noise introduced by the
D/A converter and this varies according to the quality of the
converter or the board design. Using quality components and