[comp.sys.ibm.pc.rt] CFN R-9000 Series Tape Drive

sean@adelie.Adelie.COM (Sean Conway) (02/23/89)

I recently installed a CFN R-9000 Series 9-track tape drive in a newer
Model 125 with DMA-coupled 114MB drives that is also fully loaded (AIX V2.2.0,
TCP/IP, SNA Services, Distributed Services, Rabbit 3270, etc...).

After working my way past VRM device driver conflicts with the AT Simulator,
I finally, I thought, got the thing to work...  Basically, I'm trying to
read a tape written on an IBM 4381 in EBCDIC using "dd" as following:

dd if=/dev/rtm0 of=tt.s bs=8192

Well 38 out of 40 times it read the data off the tape incorrectly WITHOUT
reporting ANY ERRORS! I was able to read the same tape 100% succesfully on
my VAX 11/750.

CFN said it's an "operator" error and we're saying the drive doesn't work
period.  All drive should be able to tell if it read bad data and throw
up a signal.

Has anyone experience similiar problems with CFN?

I'll appreciate any info or comments...

Sean Conway
Adelie Corporation
sean@adelie.ADELIE.COM

scw@ollie.SEAS.UCLA.EDU (02/28/89)

In article <22856@adelie.Adelie.COM> sean@adelie.Adelie.COM (Sean Conway) writes:
[....]
>CFN said it's an "operator" error and we're saying the drive doesn't work
>period.  All drive should be able to tell if it read bad data and throw
>up a signal.
>
>Has anyone experience similiar problems with CFN?
>
>I'll appreciate any info or comments...

Sorry for the posting, couldn't get an internet address.
Sean,
   There is a problem with the CFN 9000 controller in that the FIFO chips are
not fast enough. The simplest fix is to slow your tape drive's effective rate
down to ~ 125 KB/Sec then the fifo can keep up.  Cypher drives have an option
142-(9) in the drive to set the Interface Transfer Rate, if you set it to 126.6
(see section 4.1.2 in the M990 GCR Maintenance Manual [799981-001] Test 142)
things should work just fine.
<scw>
Stephen C. Woods; UCLA SEASNET; 2567 BH;LA CA 90024; (213)-825-8614
UUCP: ...!{ibmsupt,hao!cepu}!ollie}!scw ARPA:scw@{Ollie.,}SEAS.UCLA.EDU