17 Feb
2006
17 Feb
'06
4:42 p.m.
Zane H. Healy wrote:
At 3:43 AM -0500 2/17/06, 9000 VAX wrote:
I have an Emulex UC18 (dual SCSI, one channel setup for MSCP disk, other
setup for TMSCP tape) on my PDP-11/44. I have both 2.1GB Seagate hard
drives and DEC RRD43 (Toshiba) CDROMs on the disk port. I've used the
CDROM to boot XXDP, RT-11, BSD2.11, and RSTS. The Emulex reads the CDROM
and reports the size of the disk as the size of the drive. If no disk is
present it reports drive offline. I can mount/unmount (BSD) and switch
media in the CDROM at will.
Greeting,
May I ask how an MSCP SCSI controller behaves when a CDROM drive is
connected to it? When there is no CD in the drive, what does "show
dev" console command show? Can I take out the CD when an OS is
running? Can I take out the CD after I unmount it from the file
system?
My controller treats a CDROM drive as a read-only HD now. Please let
me know how other controllers deal with the CDROM drive. Thank you.
Good question. One thing to remember is that a lot of Q-Bus MSCP SCSI
controllers won't even talk to CD-ROM's, and if they will you have to
find one that will talk ot it. I've had good luck with Plextor caddie
drives, and an RDD-42, but I've another drive that works fine on my
Alpha's that won't work with my Q-Bus controller.
I only use my SCSI (Unibus or Q-Bus) on PDP-11's, so I don't have the
"SHOW DEV" option. Having said that, as I recall, they show up as a
Read-Only HD.