[comp.sys.att] 3b1, antistatic tab removal

ruck@sphere.UUCP (John R Ruckstuhl Jr) (06/15/90)

I have opened my 3b1 a few times during the past ~18 months to clean the
hard disk's antistatic tab (to stop hard disk whine).  At the time this
operation was discussed (~18 months ago?), some posters commented that
the tab was unnecessary, and that it could simply be removed without
harm.  
Has anyone removed their disk's antistatic tab?  Any side-effects?

[BTW, thanks to you who originally explained this fix... I had already 
had the original drive *replaced* (under warrenty) because of this 
whine, then the replacement drive began whining, and I was getting very
agitated.]


Also:
My 3b1 ingests much dust.  How do you/I remove the accumulated dust from
the opened 3b1?  (I considered wiping the motherboard with an old 
paintbrush, but worried about static (dis)charge.)


How would I checksum a diskette so that I could verify the integrity of
copies?  How about:
    $ dd if=/dev/rfp021 | sum
and perhaps better,
    $ dd if=/dev/rfp021 ibs=4k obs=4k | sum -r
Does anyone checksum backups?  Or is checksum inherent in cpio, so if
one can cpio -iBct (or cpio -iBc ?), then the backup is clean?


Thank you for any information.
Regards,
John.
-- 
John R Ruckstuhl, Jr	UUCP: sphere!ruck
			DOMAIN: ruck%sphere@hp-lsd.cos.hp.com

yarvin-norman@CS.YALE.EDU (Norman Yarvin) (06/16/90)

In article <303@sphere.UUCP> ruck@sphere.UUCP (John R Ruckstuhl Jr) writes:
>My 3b1 ingests much dust.  How do you/I remove the accumulated dust from
>the opened 3b1?  (I considered wiping the motherboard with an old
>paintbrush, but worried about static (dis)charge.)

I have used compressed gas.  Traditional products use CFCs, and I have also
seen plain compressed air for this purpose.  The last time, I just used lung
power.

Has anybody tried a fire extinguisher? (the CO2 kind, not the water kind :-))
Presumably an air compressor would also work?  Bottled gas for cleaning my
computer is not the kind of thing I like spending money on.

>Does anyone checksum backups?  Or is checksum inherent in cpio, so if
>one can cpio -iBct (or cpio -iBc ?), then the backup is clean?

I think either the kernel or the hardware writes CRCs for each disk block.
I know the standard backup routine just does a cpio -iBct (or whatever) if
you ask it to "verify the backup".  (You want the 't' option, or else you'll
be restoring.)

--
Norman Yarvin					yarvin-norman@cs.yale.edu
  "Obviously crime pays, or there'd be no crime." -- G. Gordon Liddy