CDPLAY is a command-line player for audio compact discs. What
differentiates this program from all the other CD players around (that
I could find) is that it is completely driven from the command line
rather than from the keyboard.  So it can easily be controlled from a
BAT file or another program, without manual intervention.

Also, CDPLAY is NOT a "resident" program (TSR). CD drives have the
ability to play a whole CD without any help once started, so CDPLAY
has an option to return to DOS while the CD drive is still playing. So
you can listen to your CD while using your PC for other tasks.

CDPLAY also gives you fine control from the command-line. You can
start and stop playing on any given audio track or even on a portion
of a track.

Also, you have complete control of stereo playback, any CD channel can
be played on any output channel.

There is also a SLEEP program which is a command-line delay, which you
can use with CDPLAY in a BAT file for a programmed delay between CD
selections.

C source code is provided for both CDPLAY and SLEEP (Turbo C). Also a
brief programming reference is provided.

Requirements:

CDPLAY operates through the MSCDEX interface. Generally, you have to
load a device driver and MSCDEX before you can use CDPLAY. These
programs will usually be supplied with your CD drive.

How to operate:

When you load MSCDEX it will assign a DOS drive letter to your CD
drive. This is the only required operand for CDPLAY. e.g.

   CDPLAY J

will play the CD in drive J from start to finish, in normal stereo.

The next operand will select a single track to play by track number,
or if a "+" is specified as a prefix, a starting track, with playback
proceeding to end of the CD. e.g.

   CDPLAY J 2

would play audio track two and stop.

   CDPLAY J +2

would play starting at track two but wouldn't stop until end of the
CD.

The next two operands control stereo playback. The first controls the
Left output channel; the next the Right.  L R is the default, which
plays the Left & Right CD channels through the Left & Right output
channels (normal stereo). 0 specifies no output. Some possibilities:

   CDPLAY J 2 L 0

would play only the left channel of track 2 through the left speaker.

   CDPLAY J 2 L L

would play the left channel of track two through both output channels.

   CDPLAY J 2 R L

would play track 2 in reversed stereo.

These operands are most useful with Computer CD's which also contain
audio tracks. Often the left and right channels of an audio track
contain unrelated material.

The next (fifth) operand is the number of seconds to skip from the
start of the track specified in operand two before starting to play.

The sixth operand limits playing time. It is also specified in
seconds.

Operands five & six are generally used where short excerpts of tracks
are desired, as with sound effects. They can be specified in xx.x
format for a resolution of about 1/10 second.  If operand two contains
a plus, then operands 5 & 6 can specify spanning two or more tracks.

Once CDPLAY starts, it normally remains in control until it's assigned
task is finished. While in control, it displays dynamic CD playback
information on the screen. If you press the Esc key while CDPLAY is
operating, it will immediately stop playback and return to MSDOS. But
if you press the SpaceBar, CDPLAY immediately returns to MSDOS, but CD
playback continues. You can then do other unrelated tasks on your PC
while continuing to listen to your CD.  Generally, re-booting, which
re-loads the CD device driver will reset the CD drive. If you reload
CDPLAY while the CD drive is still playing, CDPLAY will ignore all the
operands (except drive letter) and resume its dynamic display.

Both CDPLAY and SLEEP are freely distributable shareware. If you find
them useful, please send $5 to Edgar Swank, 5515 Spinnaker Dr., #4,
San Jose, CA 95123. You can also communicate with the author by
sending e-mail to

Edgar W. Swank   <edgar@HighNRG.sbay.org>
