Submission for mod-computers-pyramid

[era at mimsy.umd.edu]

Path: scdpyr!era
From: era at scdpyr.UUCP (Ed Arnold)
Newsgroups: mod.computers.pyramid
Subject: wanted: "best" tape drive for 90x
Keywords: pyramid 90x tape fujitsu kennedy
Message-ID: <40 at scdpyr.UUCP>
Date: 23 Feb 87 23:57:53 GMT
Distribution: na
Organization: Natl Ctr Atmospheric Research, Boulder, CO
Lines: 31

I'm seeking info from anyone who has attached either a Fuji M2444 or
Kennedy 9401 to a 90x (thru an IOC, of course).  Since the 90x (OSx 3.0)
I'm working on isn't source licensed, I can't look at the tape driver.

I'm trying to evaluate a loaner 2444.  It's set up in Cipher F880
compatible mode (CE manual, page 6-35) and with the buffer xsfer rate
at 250 kbyte/sec (CE manual, page 4-58).  In this configuration, at
6250 density, the best transfer rate to tape (single-user mode, 10240-byte
blocks) is about 104 kbyte/sec, which doesn't seem very good.  (Setting
higher buffer transfer rates causes tapeintr() to croak.)

My questions are:

(1) Is there any combination of Fuji parameters which will give us a
    better transfer rate on a 90x?  In particular, if we should be
    using the Fuji's CDC or PERTEC modes, what value of "ioctapetype"
    in conf.c does this correspond to?  (We're currently using "MT_UNKNOWN".
    There is a "MT_FUJITSUM2444AC" type, but the sys admin manual doesn't
    reveal whether that corresponds to CDC or PERTEC mode, and using that
    value in Cipher mode doesn't work at all.)
(2) Is there anyone out there with a 90x/Kennedy 9401 who achieves a
    significantly better transfer rate than 104 kbyte/sec?  (If we can get
    better throughput with a 9401, we would consider spending the extra
    money.)

Thanks for your assistance ...
-- 
Ed Arnold * NCAR (Nat'l Center for Atmospheric Research)
PO Box 3000 * Boulder, CO  80307-3000 * 303-497-1253
era at ncar.csnet * era at scdsw1.{arpa,ucar.edu} * era at scdpyr.uucp *
era%scdsw1.arpa at wiscvm.bitnet