Most drives have a jumper to disable paritiy generation. You could
probably get away with that on the CD drives. On the subject of jumpers,
no more than three drives on a chain are supposed to supply term power.
The only reason you supply term power from any drive is so that the active
terminator will stay "active" until the drive is fully powered down--since
the CD's are read only, it doesn't really matter, so you can disable term
power on them as well. You might need to download the documentation for
your drives. You didn't say what the physical configuration was, but those
errors from id 5 (the end drive?) have me suspecting a termination issue.

On Tue, 23 Feb 1999, Leonard C. wrote:

> With the standard SCSI driver, I'm keep getting lots of bus errors
> everytime I try to do anything disk intensive such as compile.  I switched
> over to the SBC driver, and found that all becomes well, however I can't
> access my CD-ROM drives any longer as /dev/cd? are no longer being
> correctly detected.
> 
> When I boot with an SBC kernel, I see a whole bunch of kernel messages like
> this and never see it detect my CD-ROMs:
> 
> Feb 23 15:40:12 kronos /netbsd: sbc0: parity error!
> Feb 23 15:40:13 kronos last message repeated 15 times
> Feb 23 15:40:13 kronos /netbsd: sbc0: reset SCSI bus for TID=5 LUN=0
> Feb 23 15:40:13 kronos /netbsd: sbc0: parity error!
> Feb 23 15:40:13 kronos last message repeated 24 times
> Feb 23 15:40:13 kronos /netbsd: sbc0: reset SCSI bus for TID=5 LUN=0
> Feb 23 15:40:13 kronos /netbsd: sbc0: parity error!
> Feb 23 15:40:14 kronos last message repeated 24 times
> 
> I've included the dmesg from using the standard kernel below.  I'm running
> this on a MacIIsi with 9 megs of RAM, a 40 meg internal HD, a 340 meg ext
> HD, and 3 CD-ROM drives.
> 
> I'm trying to get this thing set up as a CD-ROM server, but right now it
> seems I only have two choices: 1) Run the SBC kernel with no access to my
> CD-ROM drives or 2) Run the standard kernel and put up with the many bus
> errors and failing programs (what I'm doing right now).
> 
> Does anybody have any suggestions on what to do?  I'm feeling like I'm
> overlooking something really basic with the SBC kernel...
> 
> Leonard
> _________________
> dmesg:
> NetBSD 1.3.3 (kronosKern) #0: Mon Feb 22 23:01:28 PST 1999
>     leonard@kronos:/usr/src/sys/arch/mac68k/compile/kronosKern
> Apple Macintosh IIsi  (68030)
> cpu: delay factor 77
> real mem = 9109504
> avail mem = 5537792
> using 136 buffers containing 557056 bytes of memory
> mrg: 'Mac IIsi class ROMs' ROM glue, tracing off, debug off, silent traps
> mrg: I/O map kludge for ROMs that use hardware addresses directly.
> adb: bus subsystem
> Got following HwCfgFlags: 0xfc00, 0x    773f, 0x 1000126, 0x       0
> mrg: setup_egret:
> mrg: setup_egret: done.
> \^H\^Hadb: extended keyboard at 2
> adb: 100 dpi mouse at 3
> mainbus0 (root)
> obio0 at mainbus0
> adb0 at obio0 (ADB event device)
> asc0 at obio0: Apple Sound Chip
> intvid0 at obio0: Internal Video
> intvid0: 640 x 480, monochrome
> grf0 at intvid0
> ite0 at grf0 (minimal console)
> ncrscsi0 at obio0
> scsibus0 at ncrscsi0: 8 targets
> sd0 at scsibus0 targ 0 lun 0: <CONNER, CP3040A-40mb-3.5, 2.31> SCSI1
> 0/direct fi
> xed
> sd0: 40MB, 1026 cyl, 2 head, 40 sec, 512 bytes/sect x 82080 sectors
> sd1 at scsibus0 targ 2 lun 0: <MAXTOR, LXT-340S, 6.55> SCSI1 0/direct fixed
> sd1: 324MB, 1546 cyl, 7 head, 61 sec, 512 bytes/sect x 665154 sectors
> cd0 at scsibus0 targ 3 lun 0: <NEC, CD-ROM DRIVE:25, 1.0a> SCSI1 5/cdrom
> removab
> le
> cd1 at scsibus0 targ 4 lun 0: <NEC, CD-ROM DRIVE:25, 1.0a> SCSI1 5/cdrom
> removab
> le
> cd2 at scsibus0 targ 5 lun 0: <NEC, CD-ROM DRIVE:25, 1.0a> SCSI1 5/cdrom
> removab
> le
> zsc0 at obio0 chip type 0
> zsc0 channel 0: d_speed   9600 DCD clk 0 CTS clk 0
> zstty0 at zsc0 channel 0
> zsc0 channel 1: d_speed   9600 DCD clk 0 CTS clk 0
> zstty1 at zsc0 channel 1
> nubus0 at mainbus0
> ae0 at nubus0 slot 9: MacCon Ethernet, 32KB memory
> ae0: Ethernet address 00:00:94:22:22:d8
> fpu0 at mainbus0 (mc68882)
> boot device: sd1
> root on sd1a dumps on sd1b
> PRAM: 0x36d31a94, macos_boottime: 0x36d31a82.
> root file system type: ffs
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> cd2(ncrscsi0:5:0): error code 0
> 
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