Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!evax!cs4344af
From: cs4344af@evax.arl.utexas.edu (Fuzzy Fox)
Newsgroups: comp.sys.cbm
Subject: Re: 1571 writes slowly on side 2
Message-ID: <1991Mar28.050902.2628@evax.arl.utexas.edu>
Date: 28 Mar 91 05:09:02 GMT
References: <1991Mar28.024743.16062@gn.ecn.purdue.edu>
Organization: Computer Science Engineering Univ. of Texas at Arlington
Lines: 25

In article <1991Mar28.024743.16062@gn.ecn.purdue.edu> rferguso@gn.ecn.purdue.edu (Robert S. Ferguson) writes:
>I have noticed that my 1571 writes more slowly on side 2 of a disk.  
>After each sector is written, I can hear the head move, then move back into
>place.  The disks were formated with that same drive, and it seems to occur
>only when writing to side 2 of a disk.  What I want to know is, is this a
>problem with all 1571's, or just older ones? or is it just mine?  Can it 
>be fixed? 

This is a stupid bug in the original 1571 ROMs.  What's happening is
that every time a file allocates a new sector, the BAM block on side 1
of the disk is being read in, updated, and written out again.  This is
horribly slow.  The drive is supposed to simply keep a copy in RAM and
update after the file is closed, but it does not.

The solution is to upgrade your ROM.  You can get the upgrade from
Commodore (I think, no details here), or if you buy a replacement ROM
such as JiffyDOS, it will have the latest upgrades in place.

The upgrade will also fix (finally!) the save-replace bug.

-- 
David DeSimone, aka "Fuzzy Fox" on some networks.          /!/!
INET:    an207@cleveland.freenet.edu                      /  ..
Q-Link:  Fuzzy Fox                                        /   --*
Quote:   "Foxes are people too!  And vice versa."         /  ---