Re: Is there anyway to stop the 1541 head-banging ?
                                       
   From: John Iannetta <73510.2152@CompuServe.COM>
   Reply to: John Iannetta
   Date: Wed, 28 Oct 1998 13:08:05 -0500
   Organization: CompuServe, Inc. (1-800-689-0736)
   References:
          <3636D8B9.3AC1@chemie.uni-konstanz.de>
    Christopher A. King said,

'Boss Hogg wrote:

> Every time I power-up or reset the C64 the 1541 insists on banging it's head.
I
> understand the reasons for it but is there a way to stop it ?

There is no reason for it.  A normally working 1541 does *not* bang
against the track 0 stop when powered up or reset.  It will if it
encounters a read error or you invoke an "initialize" command from
BASIC.

As an aside, you can remove a lot of the banging by replacing the
factory stop with a "spring" of the same shape made from something
like a large paper clip (I am assuming that this is an Alps-based
1541).'.

    A 1541 shouldn't do a "bump" (bang the head against the track 1 stop) on
reset; it shouldn't move the head at all.  An INITIALIZE will not do a bump
either, unless the drive has trouble reading the disk.

    I am glad that your paperclip-stop isn't causing you any problems; you are
mighty lucky.  I wouldn't recommend replacing the track 1 stop with anything
like that.  When the drive does a bump, it tries to move the head outward 46
tracks.  If the head is on track 35, the stepping motor is pulsed 92 times
(each pulse is 1/2 track).  Ditto if the head is already on track 1.  That is a
lot of punishment for the stop.  If it bends and doesn't return to its original
form (acquires a permanent set), the drive may stop working.  After a bump, DOS
defines that track as track 1.  If track 17 was originally requested, the
controller will then move the head 16 tracks inward.  So it is important that
the track 1 stop be positioned accurately.  A half-track represents 1/96 inch.
The stepping motor's detent action ensures that the head can move only in
half-track steps.  But if the track 1 stop moves 1/192 inch outward, every
track will be off by 1/2 track.

    Also, the track 1 stop is used for defining track 1 during a format.

--
I pressed RETURN, and the message said, "Missing GOSUB".

                          John