Device name causing DVD playback problem

[Barry Yu]

In one system I installed 1 cd writer (Hardware Browser recognized it as 
scd0), and a DVD rom (Hardware Browser recognized it as _hdc_). I make a 
link ls s /dev/hdc /dev/dvd, the Mplayer is happy with this and plays 
back movies.

In another system, I install a so-call combo cd writer/dvd player/cdrom 
3 in 1, and this is the only ide cd/dvd rom in this system, and the rest 
are hard drives and floppy drive. so I made a link /dev/hdc /dev/dvd as 
above,

since then I got trouble; when I insert the regular data cd or svcd into 
it, the drive automatically detected them and a cd rom icon 
automatically appeared on desktop as well, and I can play the svcd and 
use the data cd as usual. However, when I insert a dvd into it, there 
was no cd rom icon automatically pops up on desktop, and both the Xine 
and MPlayer failed to play the dvd as they could play the svcd in the 
same drive.

When I use the Hardware Browser to look at it, and it was recognized as 
_scd0_ ! So I deleted the /dev/dvd and made another link with ln s 
/dev/scd0 /dev/dvd, this time both Xine and MPlayer can play svcd and 
dvd, but still there was no cdrom icon pop up on desktop ( Can this be 
fixed?), I replaced this combo drive with a regular single feature dvd 
rom and the result is the same except I cant use it to burn cd.

My question is : Some people using the MPlayer by making a linlk ln s 
/dev/hdc /dev/dvd and my first machine was configured that way (1 cd 
burner and 1 dvd rom) and it is working at present, how come my second 
machine dvd rom became /dev/scd0 ? Should an ide dvd rom be scd0 or hdc 
? under what condition a dvd rom be scd0 or hdc ? without the Hardware 
Browser ( It solved my problem this time) how can I identify the drive 
whether it is scd0 or hdc ( such as in command line) ?

Thanks.