In message <200112150358.fBF3wqu09186@doppelganger.waterside.net>, you write: 

-> Folks:
-> 	My CD-reader in my main development box has somehow taken a dis-
-> 	like to the commands NetBSD sends it when I ask the OS to play CDs
-> 	in that drive.  This used to work at some point in the past (though
-> 	I don't recall well enough to correlate that with a -current date).

[...]
-> cd0(ahc0:0:5:0):  command: 0x1a,0x0,0xe,0x0,0x1c,0x0-[28 bytes]
-> ------------------------------
-> 000: 1b 00 00 08 83 00 00 00 00 00 08 00 0e 0e 04 00 
-> 016: 00 00 00 00 01 ff 02 ff 00 00 00 00 
-> ------------------------------
-> cd0(ahc0:0:5:0):  command: 0x15,0x10,0x0,0x0,0x1c,0x0-[28 bytes]
-> ------------------------------
-> 000: 1b 00 00 08 83 00 00 00 00 00 08 00 0e 0e 04 00 
-> 016: 00 00 00 00 01 ff 02 ff 00 00 00 00 
-> ------------------------------
-> cd0(ahc0:0:5:0):  sense debug information:
-> 	code 0x70 valid 0x0
-> 	seg 0x0 key 0x5 ili 0x0 eom 0x0 fmark 0x0
-> 
-> info: 0x0 0x0 0x0 0x0 followed by 10 extra bytes
-> 	extra: 0x0 0x0 0x0 0x0 0x26 0x0 0x0 0x8c 0x0 0x0 
-> cd0(ahc0:0:5:0):  Check Condition on CDB: 0x15 10 00 00 1c 00
->     SENSE KEY:  Illegal Request
->      ASC/ASCQ:  Invalid Field In Parameter List
->          SKSV:  Error in Parameters, Offset 0, bit 4

Following up to myself, I figured out that this was being caused 
by the cd_scsibus_set_pa_immed() function, though I'm still not 
sure what the complaint is.  Stubbing out the MODE SENSE/MODE 
SELECT command pair that that function does gets my CD playing 
fine.

I'm still not sure why the complaint from the SCSI system about a 
0 bit in the reserved range of byte 0, but I'll try and make sure 
I don't have any odd physical issues going on on the bus first...

--rafal

----
Rafal Boni                                                  rafal@mediaone.net