From: thad@btr.BTR.COM (Thaddeus P. Floryan)
Newsgroups: comp.sys.sun.hardware,comp.sys.sun.misc
Subject: Re: Help needed for adding a HD to a 3/60
Date: 5 Apr 92 10:05:06 GMT
Followup-To: comp.sys.sun.hardware
Organization: BTR Public Access UNIX, Mountain View CA

In article <1992Apr2.023029.18855@news.iastate.edu> jwang@iastate.edu writes:
>Hi netters, I have a diskless Sun 3/60 for awhile and want to add a HD and a
>60Mb tape drive to it.  I set them up in daisychain configuration:
>
>	3/60 <--> 330MB Wren IV <--> Wangtek QIC-24 TD(with terminator).
>
>The HD has scsi id 0 and TD has scsi id 4.  When I tried to boot up from tape,
>the computer can't recognize sd0 and it gives the message: sd0: I/O request
>timeout.  They just can't communicate.  And also, I did the SCSI interface
>test at the monitor mode, the message was: scsi:dma never completed.
>
>Did I do something wrong?  The HD seems to work(the disk spins) but I wound't
>rule out the possibility.

In the "general" sense, what you've done appears fine (but see below).

Some of those errors you report are symptomatic of cabling problems.  And
you can add "getbyte error, phase mismatch" to the cabling-induced error
list, too.

As I and others have discovered and reported here, even Sun's internal-to-
their-shoebox SCSI cabling is often troublesome.  Cabling is ``THE'' number
one trouble-spot with SCSI; you must have good connections at ALL connector
points.

Many people seem to ignore or dismiss the implications of a SCSI bus' speed;
it's FAST, faster than Ethernet, and one needs to make connections with the
same care afforded ham-radio equipment.  One kinked wire and *P*O*O*F* data
corruption.

All the devices on the 3/60's SCSI bus should be configured to generate
parity (which is normally the default for SCSI devices) and to CHECK parity,
which usually requires enabling by a jumper or DIP-switch option.

What isn't clear is the NATURE of your "Wangtek QIC-24".  What I mean is,
is it connected to an Emulex MT-02 SCSI:QIC translator or is it an embedded-
SCSI tape drive?

If it's on an Emulex MT-02, then you need to set the DIP-switch (on the MT-02
board) per:

	SW1-7	SW1-6	SW1-5
	  0	  1	  0	Wangtek series 5000
	  0	  1	  1	Wangtek series 5000E

From /usr/include/sys, the list of default supported QIC tape drives comprises:

	Archive QIC-11
	Sysgen QIC-11
	Sysgen QIC-24
	Emulex MT-02 QIC-24
	Archive QIC-150
	Wangtek QIC-150

and that's it; if your device is responding (to a SCSI INQUIRY) with something
other than one of the above (literal strings), a (GENERIC) SunOS kernel and/or
the boot code won't recognize it.

That Emulex MT-02 supports drives such as Archive 5945, Cipher QIC-36, Wangtek
and Kennedy (all of which read/write QIC-24 format tapes [9 trk, 1000 bpi, for
60MB on DC600A/QD600A cartridges]).

And, for the record, an Archive QIC-24 2060S (embedded SCSI) isn't recognized
either though the QIC-150 2150S works just fine (SunOS 4.1*).

Note that two major variations of the Wren IV drive have two DIFFERENT methods
to enable parity checking.  Also note the Wren IV is troublesome regarding
application of +5 VDC on SCSI wire 26 (TERMPWR); what I do is pull pin 26 out
of the IDC 25x2 connector shell before clamping the connector onto ribbon cable
to avoid "power supply fandango" on the SCSI bus.

Without additional info (model number AND board number of the Wren IV (since
there are so many variations), and model number and interface type of the
Wangtek tape drive), help is limited to the above generalizations.  Sorry.

Thad Floryan [ thad@btr.com (OR) {decwrl, mips, fernwood}!btr!thad ]