[decus.pdp11] EXABYTES on PDP-11 systems.

geremin@decus.com.au (01/08/91)

Hello PDP-11 Users - wherever you are. A DECUS colleague is 
having an awkward problem with `his' PDP-11/83 system. He has 
been trying for over 6 months to get an EXABYTE type drive 
installed using 3rd party interface onto the Q-BUS.

Configuration is approximately:-
	PDP-11/83
	4 MByte Memory
	DEQNA (Note NOT DELQA upgrade)
	TSV05 Interface
	2 x Viking SCSI Interfaces for EXABYTE
		(previously tried with DILOG also).
	5 x DHV11 MUX boards
	LPV11 Printer I/F
	KDA50 with 2 x RA81.

Main problems are - management wants two EXABYTES on TWO SCSI 
Controllers, System is a factory production machine with very 
little free time available for testing, site is 300 miles from 
DEC Head Office in Australia (and 3rd party vendor), at least two 
different DEC engineers have worked on system in last year, 
system only recognises one SCSI interface, system hangs 
infrequently without proper crash, system had silly timing 
problems 12 months ago before TSV05 I/F was moved to immediately 
after DEQNA (which I know should be upgraded!), BACKUP fails 
diring DIR listing of EXABYTE after copying files (not during 
file transfer), I do not have instant access to all the hardware 
manuals for all the devices in use, nor to all the recent 
software dispatch articles for RSTS/E v9, local vendor does not 
seem to be able to get much specific info from SCSI I/F makers re 
PDP-11 systems, one respected friend in DEC Aust says that 
EXABYTES and PDP-11s are INcompatible, yet DEC field service have 
agreed to install and maintain the 3rd part SCSI boards.

I need help (as do DEC field service, the user and the vendor - I 
am talking to all three at different times) - and advice.

* Does RSTS/E v9.6/v9.7 really handle STREAMING Tape Devices 
   successfully.?
* What are real differences between VAX Q-BUS and PDP-11 Q-BUS 
   (other than increased speed on newer VAXen).?
* Does anyone have a running (and happy) EXABYTE on a PDP-11 
   Q-BUS system.?  (Is UNIBUS any better or worse).
* Is anyone using the DEC KZQSA interface (with TLZ.. device) on 
   a PDP-11 system.? (If so what config and O/S)
* How serious is the old DEQNA board (without DECNET Phase V).?
* Is there a possibly timing conflict with KDA50 on Q-BUS (as 
   there was with the UDA50 on UNIBUS with 11/70).
* What is recommended configuration for these types of 
   interfaces.? (Order on BUS etc).
* Is there a similar configuration in Australia.? (or Anywhere?)
   (Does not really have to be running RSTS/E).
* Do we need to turn OFF data-cacheing to slow down the transfer 
   rate during BACKUP.?
* Does v10 claim to cure any of these possible problems.?

Thanks to all, in advance as usual,

	PS. to Terry Kennedy, `What other questions should I be 
                              asking to get the correct answers'?
   John G.
v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v*v
 John Geremin, 	  PDP-11  SIG,		geremin@decus.com.au
 DECUS South Pacific Chapter.            phone (02) 764 4855. 
c/-  MEGATRONICS, p.o.box S-5, Homebush South, 2140. Australia.
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