Re: Low Level Format of 1.4 Mb Floppy Isn't Happening Solved.
On Sunday 15 January 2017 16:36:08 Martin McCormick wrote:
> I must first say a big thank you to everybody who helped.
>
> I got it working and here is what happened and how to
> format a totally blank diskette.
>
> The man page for setfdprm should have had at least one
> example of how to use it since syntax, especially for something
> one doesn't use every day, is not intuitive and can cause hours of
> prodding and head-scratching/banging.
>
> In my searching via Google and reading some of the
> articles and discussion group postings, I learned that there is a
> companion to setfdprm which is getfdprm. I put in a good and
> formatted floppy and ran getfdprm on a 1.44 Mb disk. The
> application produced
>
> DS HD sect=18
>
> This occurs after you have spun the disk to mount it or done
> anything else to make the disk turn for reading.
>
> If you eject the diskette, the value stored in setfdprm
> vaporizes, assuming that one's floppy drive's disk-change switch
> is working.
>
> I figured that this value or
>
> DS DD sect=9
>
> for a 720 K diskette was worth passing to setfdprm so I wrote the
> following shell script:
>
> #!/bin/sh
> #1.44Mb disk Uncomment line below.
> #setfdprm /dev/fd0 DS HD sect=18
> #720K disk Uncomment line below to use it.
> #setfdprm /dev/fd0 DS HD sect=9
> #fdformat /dev/fd0
>
> It will begin by identifying that this is a double-sided disk and
> will start laying down tracks from 0 to 79 and then verify their
> presence.
>
> You can skip the verification process in fdformat but I
> don't advise it as I tried some old 720K disks that formatted all
> 80 tracks and then track 0 was dead on all of them.
>
> Another warn-out disk formatted and verified until track
> 76 was reached and then it cratered with the same error that
> befell the 720K disks.
>
> A new (unused until now) 1.44 Mb disk formatted and
> verified all 80 tracks so the drive appears to have no
> electro mechanical issues on good media.
>
> On the disk with a dead track 76, the error caused the
> heads to seek all the way back to track 0 and then forward to 76.
> One could hear it rip-sawing back and forth which was probably
> good exercise for a drive that doesn't get much usage these days.
> After trying to read track 76 many times, the verification
> aborted with a message stating that this track was bad.
>
> Anyway, this has been an interesting journey down memory
> lane. Stuff just works a lot better these days than it used to.
>
> Martin McCormick WB5AGZ
And any drive thats 10 years old & maybe even some newer ones are
desperately in need of being pulled out, and any covers that are
blocking good access to the carriage drive screw, need to be uncovered
for a serious cleaning with alcohol or even acetone so that no debris or
solidified grease can be found on the screw, followed by a pebble of
lithium chassis grease worked back into the groove of the screw. Put it
back together & back into the computer. It the q-tip isn't too dirty,
wipe a thin film of grease on the rails the head carriage slides on, but
more likely it would get a fresh & some clean grease. It might work
another for another ten years!
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
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