🚀 go-pugleaf

After installing 3.0 on all our machines the CD-ROM drive wasn't used too much  
anymore. And to prevent it from being misused by installing NT on PCs (argh!) I  
thought it could be a good idea to play back audio CDs. But unfortunately we  
don't have an amplifier and speakers here, so I tried to read the data directly  
off the CD and play it using the DSP. I wrote the following program which  
constantly failed working when I inserted audio CDs. However, it works fine  
with data CDs although the "music" isn't too enjoyable...

	struct timeval		tv;
	struct esense_reply	esense;
	int			fd,err,length=10,firstBlock=1024;
	SNDSoundStruct		*snd;
	char			*buf;

	fd=open("/dev/rsd1h",O_RDONLY,0);
	SNDAlloc(&snd,length*2048,SND_FORMAT_LINEAR_16,SND_RATE_HIGH,2,0);
	buf=(char *)snd+snd->dataLocation;
	bzero(buf,length*2048);
	err=do_read2(fd,firstBlock,length,buf,&tv,&esense);
	SNDStartPlaying(snd,1,2,NO,SND_NULL_FUN,SND_NULL_FUN);

do_read2 is a modification of the do_read function in  
/NextDeveloper/Examples/UNIX/SCSI_CD/scsi_commands.c. I replaced the following  
lines to really read the data into a buffer:

	sr.sr_addr = buf;
	sr.sr_dma_max = 256;
	sr.sr_ioto = 5;
	sr.sr_dma_dir = SR_DMA_RD;

The following messages showed up in the Console window:

sd1 (6,0): ERROR op:0x8 sd_state:4 scsi status:0x0
sd1 (6,0): sense key:0x5  additional sense code:0x64
    SCSI Block in error = 1024 (no valid label)

Is this due to the fact that (a) the disk doesn't have a label (I thought those  
"live" partitions were introduced for such cases) or (b) "something" in the  
CD-ROM drive ensures that no digital copies of audio CDs can be made?

Erik Doernenburg
___________________________________________________________________
AMG Industrie Consulting GmbH (NeXT mail)               erik@amg.de
Universitaet Dortmund   knight06@pandora.informatik.uni-dortmund.de

-- 
Johannes 5 Joemann
Wissenschaftsladen Dortmund, Lindemannstr.84, D(W)-4600 Dortmund 1
Tel. 0231-104002 (ggf. Anrufbeantworter)
WILADO@DOO.ZER, joemann@anarch.do.open.de