Apple CD-ROM Init Speedup

Apple CD-ROM Init Speedup

Post by Andy Peterm » Sun, 02 Dec 1990 06:33:00

If you have been finding your inits seem to take forever to finish when
you start up your Mac, here's a speedup patch for one of the worst
offenders, the Apple CD-ROM Init.  This init scans all 7 SCSI addresses
looking for your CD-ROM, a potentially time consuming task, especially if
you don't have your CD-ROM turned on (I turn mine off when I'm not using
it because its so noisy).  The init normally starts looking at SCSI address
0 and keeps going up through address 6, unless it finds the CD-ROM first.  
Each address check takes a few seconds.

The following patch will allow you to tell the init to check only the
specific address (or range of addresses) that you have set your CD-ROM
to.  Once you have made the patch, all you need to do is modify a resource
within the file to change it to any other address.  Make this patch ONLY to
version 2.0 of the Apple CD-ROM file.

1.  Open the Apple CD-ROM (Version 2.0) Init file with ResEdit.

2.  Open the INIT 1 resource.

3.  At an offset of 0012, change 42 53 to 4E 71.

4.  At an offset of 006C, change 34 93 4E 75 to 60 00 03 40

5.  At the end of the resource (offset of 3AE) add the following:
    34 93 45 FA FF 94 34 AB 00 02 45 FA FD 50 34 AB 00 04 4E 75

6.  Close the INIT 1 resource.

7.  Open the INLP 0 resource.  It should contain just two bytes, 0001.
    This value is the number of times the code will scan the range of
    SCSI addresses.

8.  Add two 16 bit values to indicate the starting address to check and
    the ending address + 1 to stop at.  For example, if your CD ROM is set
    to SCSI address 3, then this resource should contain 0001 0003 0004.
    To retrun to the normal scan of all SCSI addresses (0 to 6), then the
    resource should contain 0001 0000 0007.

9.  Close the resource and the file.  If you're a using virus protection
    program, it may give you a warning.  This is normal since you just
    modified an INIT resource.

    Andy Peterman

DISCLAIMER:  The opinions and information expressed here are my own.
I'll assume no responsibility if this patch erases your CD-ROM.


1. 840AV/Quicktime 1.6.1/CD-ROM Init Problem

I am having problems with Quadra 840AV's running Quicktime 1.6.1 and the Apple CD-ROM

My problems started about 8 weeks ago when our first Quadra 840AV arrived.  After I had
been using the machine for several days I noticed that it would hang when playing
quicktime movies.  I tried a number of players (MoviePlayer, FusionRecorder, Premiere 2,
etc.) - they all would hang the machine randomly during movie playback.

After some determined hunting, I determined that if I took the Apple CD-ROM init
out of the extensions folder, my movies would play without any problems.  In fact,
I took all the inits and control panels out at one point except Quicktime 1.6.1 and
the CD-ROM init, just to prove that it wasn't a problem caused by another piece of
software (it wasn't).  This situation is quite repeatable: CD-ROM software active
at boot-up= movies hang;  CD-ROM init removed at boot= movies play fine.

Our second 840AV arrived two weeks ago, and it exhibits the same behaviour, but more
so with the MoviePlayer than other players - it crashes very rarely (less than once
a week) when playing movies from other software.  Again, if I remove the CD-ROM init
from the extensions folder, MoviePlayer works fine.

I even had the hard disks swapped between the two machines to determine if the problem
was hardware related.  It doesn't seem to be - after the swap, the newer machine played
up as much as the older machine had been.  This definitely seems to be a software problem.

Has anyone else experienced any similar problems?  I can't believe that I can have
these problems from two out-of-the-box machines without anyone else seeing the same

BTW - The machines shipped with CD-ROM software version 4.0.2.  I downloaded 4.0.5 from
AppleLink, but this made no difference (in fact, the INIT version in the 4.0.5 distribution
is still 4.0.2).


Technical Services Manager            Phone : (003) 243 366
Department of Applied Computing & Mathematics
University of Tasmania at Launceston, Australia

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