tyger@well.UUCP (Richard A Childers) (03/20/86)
Hello, all, a question for those with knowledge and a willingness towards
sharing it :
I have an old CP/M machine with the traditional Z80 and 64 kb RAM, and two
floppy disk drives, Shugart 801's ... 8", SS/DD.
These drives are, over the ages, becoming less and less reliable. So far as
I can tell, it's not a matter of hardware errors or anything, really, but
I continually get these little TRAC errors. ( Which means that the head is
not reading the track correctly, I believe. )
Now, from what I've read, it's quite common for your heads to drift from
the original alignment, and it's a relatively small matter to re-align them
if you have the appropriate devices to support your effort.
An oscilloscope, I have access to. What I need, I think, is a master disk,
a metal diskette with master tracks, made out of metal, instead of floppy
material - a hardware reference point by which the disk heads are aligned.
The standard 77 track, 8 inch, single density IBM 3740/1D format for which
these drives were made for.
I haven't really made a serious effort to look around for this, yet. I have
reason to believe (a) that they are generally unavailable in all the best
shops, as Shugart drives are basically as obsolete as skeleton keys, and
(b) that the drive manufacturers made these special alignment disks mostly
unavailable for the general public, to facilitate the existence of small
repair shops and discourage people from doing their own maintenance.
Does anyone out there in net.land have any ideas on where I might find such
a metallic master alignment diskette ? I'd be greatly appreciative, and so
would thousands of others with similiar problems, since the 8" diskette is
not yet dead, I suspect, and there must be others with a similiar problem ...
Thanks, awfully, lads and ladies ...
-- richard
--
"The way to do is to be." -- Lao Tzu ... circa 500 B C ...
..{dual,glacier,hplabs}!well!tyger aka Richard A Childersphilip@amdcad.UUCP (Philip Freidin) (03/21/86)
In article <813@well.UUCP>, tyger@well.UUCP (Richard A Childers) writes: > > Hello, all, a question for those with knowledge and a willingness towards > sharing it : I'm silly enough to try and help > > I have an old CP/M machine with the traditional Z80 and 64 kb RAM, and two > floppy disk drives, Shugart 801's ... 8", SS/DD. > so do I. > These drives are, over the ages, becoming less and less reliable. So far as > I can tell, it's not a matter of hardware errors or anything, really, but > I continually get these little TRAC errors. ( Which means that the head is > not reading the track correctly, I believe. ) > Could also be a seek error. just needs some VERY light machine oil on the guide rods. > Now, from what I've read, it's quite common for your heads to drift from > the original alignment, and it's a relatively small matter to re-align them > if you have the appropriate devices to support your effort. > > An oscilloscope, I have access to. What I need, I think, is a master disk, > a metal diskette with master tracks, made out of metal, instead of floppy > material - a hardware reference point by which the disk heads are aligned. > The standard 77 track, 8 inch, single density IBM 3740/1D format for which > these drives were made for. > NO. The alignment disks (or "Analogue alignment disks" (same thing)) are normal 8" floppy media, but with special info written on them. Normal drive electronics and controllers can't write this info. These disk are usually available from the major disk manufacturers such as Dysan, Memorex, Verbatim, etc. cost is about $50. > I haven't really made a serious effort to look around for this, yet. I have > reason to believe (a) that they are generally unavailable in all the best > shops, as Shugart drives are basically as obsolete as skeleton keys, and > (b) that the drive manufacturers made these special alignment disks mostly > unavailable for the general public, to facilitate the existence of small > repair shops and discourage people from doing their own maintenance. > > Does anyone out there in net.land have any ideas on where I might find such > a metallic master alignment diskette ? I'd be greatly appreciative, and so > would thousands of others with similiar problems, since the 8" diskette is > not yet dead, I suspect, and there must be others with a similiar problem ... > > Thanks, awfully, lads and ladies ... > > -- richard > soooooo... 1) First check head stepping. I use DU or DUU to generate complex stepping patterns, and then whatch for error messages, and also whatch the heads. 2) To do a re-alignment, you will need an analogue alignment disk, and a dual channel scope (like a tek 465). The alignment disks come with instructions for use. different tracks have different test patterns on them to facilitate the various parts of the alignment process. Circuits for the drives can also help 3) good luck. 4) If you need help, call me (408)737-8060 (after 7:00 pm) philip. ... Only a fool volunteers help.... philip @ ....{ how ever you get here }!decwrl!amdcad!philip
mc68020@gilbbs.UUCP (Tom Keller) (03/22/86)
In article <813@well.UUCP>, tyger@well.UUCP (Richard A Childers) writes: > a metal diskette with master tracks, made out of metal, instead of floppy > material - a hardware reference point by which the disk heads are aligned. > The standard 77 track, 8 inch, single density IBM 3740/1D format for which > these drives were made for. No, the alignment diskette is not made of metal, it is made of very ordinary mylar, like any other diskette. The nature and placement of the signals recorded *ON* the diskette, however, are quite special. If you contact Verbatim Corpoation, I believe they will sell you an 8" alignment diskette. Expect to pay between $50 and $100 for it, however. After that, all you need is the service manual for the drive, so you'll know which test points to monitor for the "cats-eye" image used to align the head. -- ==================================== Disclaimer: I hereby disclaim any and all responsibility for disclaimers. tom keller {ihnp4, dual}!ptsfa!gilbbs!mc68020 (* we may not be big, but we're small! *)
tom@pedsgo.UUCP (Tom Gillispie) (03/26/86)
Organization : Concurrent Computer Corp. (a P-E company), Tinton Falls, NJ Keywords: Shugart, Lubrication In article <813@well.UUCP>, tyger@well.UUCP (Richard A Childers) writes: > > Hello, all, a question for those with knowledge and a willingness towards > sharing it : > > -------- Description of Shugart 801 problems, alignment disks, etc ----- One thing discussed in the original posting concerns me. I, too, have received suggestions about LIGHTLY oiling BOTH the guide rods and the lead screw itself. However, when I dug out my Shugart Associates Maintenance Manual, it clearly states that NO lubrication of the drive should be done, as the lubrication "allows dust and dirt to accumulate". I once read a tale about someone who 'lubricated' the lead screw in his drive with WD-40. Unfortunately, it disolved something which must have coated the lead screw into a goopy mess! Is there anyone who can contribute pro or con points of view about guide rod and/or lead screw lubrication? I have one other suggestion for ailing Shugart drives (and perhaps others, too). I found that the little plastic and cloth button which pushes against the back side of the floppy disk in order to ensure good read/write head contact with the disk may need attention. It is called the R/W Head Load Button. These are present ONLY on single-sided drives, obviously. The buttons on my Shugart drives had a very glossy appearance, I suspect from some bad disks which caused excessive oxide build-up. The maintenance procedure in the Shugart manual describes rotating the head load button to improve the amplitude of the read/write head signal. Finally, (sorry for the length), Shugart's part number for their 'Alignment Diskette' is SA120-1. This was obtained from an OLD manual, there may be a newer revision. -- NAME: Tom Gillispie UUCP: ...{pesnta|prcrs|princeton|topaz|hjuxa|vax135}!petsd!pedsgo!tom USnail: CONCURRENT Computer Corporation (a Perkin-Elmer Company) M/S 307, 106 Apple St., Tinton Falls, NJ 07724 MA BELL:(201) 758-7321