Megalextoria
Retro computing and gaming, sci-fi books, tv and movies and other geeky stuff.

Home » Archive » net.micro.cbm » 1541 Disk Alignment Software Review
Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend 
Switch to threaded view of this topic Create a new topic Submit Reply
1541 Disk Alignment Software Review [message #74090] Sun, 26 May 2013 20:53 Go to next message
Anonymous
Karma:
Originally posted by: mrr@rayssd.UUCP
Message-ID: <535@rayssd.UUCP>
Date: Thu, 11-Oct-84 12:49:50 EDT
Article-I.D.: rayssd.535
Posted: Thu Oct 11 12:49:50 1984
Date-Received: Sat, 13-Oct-84 06:00:48 EDT
Organization: Raytheon Co., Portsmouth RI
Lines: 76


Before I begin...I recently submitted a review of the MAE assembler/devel- 
opment system, but I think I screwed up on distribution.  If you didn't see
it and are interested, let me know.

Last night I realigned my secondary 1541 disk drive (sigh of relief) with 
the help of a software package I recently purchased from C.S.M. software
of Indiana.  Anyone who has owned a 1541 for more than a year (sometimes less)
has probably encountered alignment problems by now, even if it is not 
recognized as such.  The problem is especially noticable when loading 
programs - much clanging (head reset) and flashing of the busy light.  

Well, my older drive got so bad that it couldn't read disks created by the
newer one (and vice versa) so I decided to do it myself.  The alignment kit
comes with two diskettes - a program diskette and a calibration disk.  
Operating instructions come in a very thin (but complete) 8 x 11 stapled
booklet.  My first attempt to load the software resulted in a dismal failure.
after about a minute, my screen went blank and the disk continued to spin.
After trying several resets, I called the company (Friday afternoon) and
talked to someone technically competent who stated that the software protection
scheme was preventing the load, probably because my drive was out of alignment -
quite a catch-22!  He asked if I had access to another 1541.  I explained that
I did not and that the problem was on my good 1541 which had no problems
with other commercial software.  That established, he agreed to mail a new
set of diskettes.  They arrived a week later with a return authorization for
the original pair.  I guess that establishes a certain amount of respectability
though the additional wait was aggravating.

The alignment procedure starts out with the dismantling of your drive, 
removing the chassis from the plastic housing, removing the metal shield and
(moan!) removing the printed circuit board from the chassis.  The alignment
must be done with power applied to the drive in its nude condition with the
pc board floating (I protected its bottom with a taped-on double sheet of
paper).  The first operation consists of a speed adjustment which is quite
easy.  You adjust a potentiometer while a speed percentage is displayed on 
the monitor - 100.00 % is the goal, though allowable tolerances are given.

You next execute the 'Bump and Alignment' procedure which I found to be
quite painful.  According to the instructions, the busy light (red indicator)
will stay on continuously when you have a good alignment.  I never did
reach that condition, so I settled for the least amount of flicker I could
achieve.  Also, the stepper motor cam, after a 'bump', should be pretty
close to .010 inch from the cam stop.

The 'Check Alignment' test actually steps through a series of tracks and
sectors, using the calibration diskette, and timing the operation.  After
each cycle, a "T.N." number is reported which should be close to 100.  
Again, tolerances are given.  My final result was 100.05 which I assume is
pretty good.  

By repeating these two procedures, it appears that you can achieve a good
alignment.  I created a new calibration disk (on both drives) and tested
them on my newly aligned drive with very consistent good results.  I also
made a backup copy of a large assembler application on the secondary disk,
then ran the assembly on the primary using the backup with no sign of a 
stutter - impossible before I started.

Also included in the instructions is a method for pinning the cam to its
shaft (for the very brave) since it is the cam that apparently slips,
causing misalignment.  I may try this a few alignments down the road, but
not now.

This package does not have a polished, "professional" appearance.  No fancy
labels and documentation could be proof-read and enhanced, but I am well
pleased with the results.  If you have common sense, fair mechanical ability
and some patience, this package will save you a trip to the repair shop and
at 39.95, will probably pay for itself the first time you use it.

I am very interested in others opinions and experiences with commercially
available software and hardware for the Commodore 64.  It's hard to get
past the hype (and sometimes understatement) in advertising to determine
the usefulness of a product.  If you've purchased a product that you 
consider noteworthy (good or bad), please share it with all of us.  

Mark Rinfret
SofTech, Inc.
Re: 1541 Disk Alignment Software Review [message #76151 is a reply to message #74090] Wed, 29 May 2013 23:44 Go to previous message
doug is currently offline  doug
Messages: 117
Registered: May 2013
Karma: 0
Senior Member
Message-ID: <183@terak.UUCP>
Date: Wed, 24-Oct-84 13:44:19 EST
Article-I.D.: terak.183
Posted: Wed Oct 24 13:44:19 1984
Date-Received: Sun, 28-Oct-84 05:57:38 EST
References: <535@rayssd.UUCP>
Organization: Terak Corporation, Scottsdale, AZ, USA
Lines: 44

[]

> 
> Last night I realigned my secondary 1541 disk drive (sigh of relief) with
> the help of a software package I recently purchased from C.S.M. software
> of Indiana.  Anyone who has owned a 1541 for more than a year (sometimes less)
> has probably encountered alignment problems by now, even if it is not
> recognized as such.  The problem is especially noticable when loading
> programs - much clanging (head reset) and flashing of the busy light.
> 
> ...  If you have common sense, fair mechanical ability
> and some patience, this package will save you a trip to the repair shop and
> at 39.95, will probably pay for itself the first time you use it.
> 

How does the price of the package compare with the 39.95 alignment?

By the way, if you can bear to part with your drive for a while and
feel you can trust Commodore, Commodore will *REPLACE* your 1541 with
a *BRAND NEW* unit for $85.00 by mail.

For those who might not know... there are two indications that you have
an alignment problem.  The most obvious is the BRR-A-A-A-A-P of the
head mechanism being slammed against the stop, although this is normal
  1) on the first use after power has been turned on,
  2) during a "New" operation,
  3) when loading many "copy protected" commercial programs.

An earlier and more reliable warning is the sound of the head being
"overstepped" and brought back in the hope that the track can be
read by coming at it from the other direction.  This gives a
"clickity-click..click..click" sound, accompanied by the red
light flashing momentarily.  If this is happening with any
regularity, you probably have alignment problems developing.

By the way, my 1541 had alignment troubles, and I tried all of the
"simple" fixes (clean the band and pullies, clean the head, adjust
the band tension, adjust the track-0 stop, time the drive motor)
to no avail.  What fixed it was the genuine "adjust the stepper
motor while watching the oscilloscope" alignment.  Makes me a
bit suspicious of claims that simple fixes will do the job, but
this WAS just ONE instance.

Doug Pardee -- Terak Corp. -- ..!noao!terak!doug
  Switch to threaded view of this topic Create a new topic Submit Reply
Previous Topic: C64 reset problems
Next Topic: Sending break from a C64
Goto Forum:
  

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Fri Mar 29 07:03:11 EDT 2024

Total time taken to generate the page: 0.22151 seconds