Fred's Follies



Author: Fred Cranston

Date: July  , 1987

Keywords: column HFS ROMs autosave macwrite writenow

Text:
     I would like to share with you an experience which wastefully
taught me one of the differences between HFS used in Macs with 128K
ROMs and MFS used in Macs with 64K ROMS.  At home I have a Mac+ (HFS)
with HD-20;  at school a 128K upgraded to 512K (MFS) with an external
800K drive.  I wasted about 3 hours one afternoon because I initialized
an 800K disk to use as a special boot disk for my new WriteNow
application.  I transferred a System Folder and WriteNow to the new
disk.  Everything on the disk would work fine if I used my old boot
disk, but if I tried to boot with my new WriteNow boot disk I got the
''Sad Mac'' symbol.  After finally discovering what had happened, I
thought I should share it with you.  Here is the problem.
     A normal HFS Mac can read and use an MFS disk but a normal  MFS
Mac will only be able to read and use the HFS disk if it has an HD-20
file stored in the System Folder of the boot disk (at least this is for
System version 3.2).  However (and here is what took me so long to find
out), if you have HD-20 in your System Folder and initialize an 800K
disk in the external drive, it will initialize in HFS instead of MFS. 
A 68K ROM Mac will only boot with an MFS disk, but when it is booted
MFS it can read HFS disks if the HD-20 file is in the System Folder. 
It will not boot with an HFS disk.  Here was my problem.  I was using
an MFS boot disk to copy files, including System and Finder, onto an
HFS initialized disk which could not be used as a boot disk.  The moral
of the story is:  be very careful if you intend to mix HFS and MFS.
     My second folly deals with a new DA called AutoSave.  AutoSave
will save every x minutes, where you choose x.  Unfortunately it saves
by using Command-S.  Which, in MacWrite applications, means to use
Shadow style.  Thus, instead of saving every minute as I chose to do, I
would turn my MacWrite typing into Shadow.  It works fine with WriteNow
where Command-S means SAVE.  I guess I'm going to have to learn about
FKeys to straighten this out.

Copyright © july , 1987 by Fred Cranston