First Class Peripherals Sider D4, Инструкция по установке и эксплуатации

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are marked for a reason and should not free them. (UNODOS,
for example, marks exactly 400 blocks.)
The most important block on a ProDOS volume is block 2. Since
it is accessed much more often than any other block, it is also the
most likely to be damaged. If it is, you will probably see a mes-
sage in MR.FIXIT that block 2 is too damaged for the program
to function. There is a special provision for attempting a repair
of the main directory, and it is accessed automatically when you
request Fix mode and block 2 has extensive damage. You can
also force this mode by selecting M at the Test/Fix prompt. You
will be asked if the program should assume that the ‘bit map” is
valid (default
=
Yes). Ordinarily you should select Y unless
there is some reason to believe the bit map is damaged. (For ex-
ample, if you are trying to resurrect the sub-directories after a
disk has been “wiped” by SiderFile then the bit map will NOT
be valid and you must select N at this prompt.)
When this mode has been selected by M or automatically because
block 2 has been determined to be substantially damaged
MR.FIXIT will tell you that this attempt is being made, and will
give a few particulars along the way. Although the routine can
resurrect most sub-directory pointers, it cannot do anything for
standard (non-sub-directory) files in the main directory. While
this routine is operating, every block on the volume will be read.
This may take some time, so be patient. When it is finished, you
will get the “Another?” message. Note that this routine does not
do the other repair jobs mentioned above. You can run through
the disk test again to check if those things are all right. You
should realize, however, that this main directory repair routine
expects most of the rest of the volume to be reasonably valid and
normal. (For example, it assumes that the “bit map” starts on
block 6 if the main directory header has been damaged. This is
true for almost all disks, but not for some RAM volumes; this
routine should not be attempted on a RAM volume or any other
volume you suspect is organized in an unusual way.
If you select the Bad block mode then you will be asked if you
want only to test or to fix. If you select test then the volume will
simply be scanned for bad blocks and the results reported. If you
select fix then there will be an attempt to place the bad blocks
found in a bad blocks file. This file will be created in the main
volume directory (so be sure there is room for it). If a bad block
AUXILIARY PROGRAMS 9 1