Advice on VAX peripherals wanted

kermit%brl-vgr at sri-unix.UUCP kermit%brl-vgr at sri-unix.UUCP
Sat Jan 7 00:03:17 AEST 1984


From:      Chuck Kennedy <kermit at brl-vgr>

Personnally, I would never buy an RP07.  They seem to break quite often.
There is an RP07 on a VAX 780 downstairs that is always causing problems.
The Fujitsu Eagle is a very nice drive which is what I would recommend.
I would also take the Eagle over the RA81 if you could only connect the
RA81 through the UDA50.  The problem is that the UDA50 eats about half
the Unibus and with only one drive you won't get much performance.  It
is fairly obvious that if you connect to the CMI you should higher bandwidth
than connecting through the Unibus, no matter what the salesman says.

Digital has announced the Digital Storage Architecture (DSA) which
utilizes their nifty new HSC50.  The connection to the HSC50 is via the
Computer Interconnect (CI) bus which has a 70Mbit/sec bandwidth.
The HSC50 has some really neat features such as disk shadowing
(all your disk operation are written to a tape drive which is
also attached to the HSC50) so that you have a continuously
updated copy of what your system has done (great for error recovery).

I only have two problems with the HSC50:
	1)  If you don't run VMS (i.e. UNIX), you will have to write DSA
	    code to run the HSC50.  This is probably more complicated
	    than your average driver.  Besides, you have to yank teeth
	    to find out all the information from DEC.
	2)  I don't know if it's available for use with the 750 yet.

As for tapes, I would recommend one of the triple density (800/1600/6250
bpi), 125 ips tape STC drives available from somebody like Systems Industries
connected to your choice of either a Unibus or CMI interface.  The tape
drive is fast!  The only problem is the cost (see your local representative).
I'm sure that Emulex also offers the same type of equipment.

Hope this information proves useful and happy hunting!
					Cheers,
						-Chuck Kennedy
						<kermit @ brl>



More information about the Comp.unix.wizards mailing list