ranger@ecsvax.UUCP (05/07/87)
Apple IIGS: Recovering a corrupted ProFile
In the Apple IIGS, the bus' higher 'noise' passes on to the ground traces
on the ProFile interface card and, after use, corrupts the directory of the
ProFile, rendering it invisible to ProDos and inaccessible to the user.
It is possible to recover the directory and make the ProFile usable again. On
the report of a ProFile going bad after installation in a Apple IIGS, first
see a dealer or follow the 'ProFile Interface Card Modification' procedure
outlined in the Service/HTS article within the Technical Support news.
The modification lets the card operate correctly for the directory fix.
Don't try to repair a directory with an un-modified ProFile card.
For the recovery, use a disk editor program, like the ProDos MLI Exerciser
program here:
1. Execute the ProDos Machine Language Interface Exerciser program with
the '-' command and wait for the main menu.
2. From the main menu, type '80'<Return> to command a read of a block;
follow that by typing in the following values from the next screen:
Parameter Count $03 (Default)
Unit Number $50 (The ProFile card's slot followed by a '0')
Data Buffer $00 (This value is where the block to be modified
$40 will be loaded)
Block Number $02 (This is the bad block to load in)
$00
After typing in each pair of numbers, press <Return> to go on to the
next entry prompt. After pressing <Return> on the last entry, you see a
message 'PRESS RETURN TO EXECUTE COMMAND', you press <Return> and then
see another message 'Error $00: Call Successful'. At this point, press
<Return> to get the main menu.
3. Type 'M' <Return> to modify the buffer. The default should read:
$00
$40
This is the correct setting; press <Return> on each entry and press it
once more to go on to modify mode. At this point, you should see a table
of numbers and a blinking cursor on the entry we want to 'delete', number
'55'. Now that we know that problems with the directory exist, press
<ESC> to go to the main menu.
If the '55' was not in the first position of the table, then this
directory recovery procedure won't work. If the '55' was not shown at
all, your ProFile possibly has a different reason for not operating)
4. Type '81' <Return> to write the block out to the disk. Press <Return>
through the number entries until you reach the 'data buffer' entry.
Change it to look like this:
$01
$40
Continue to press <Return> through the block number entries and once
more to command the actual block write, after which you will see the
message 'Error $00: Call Successful' will be displayed.
5. You may now reboot your system and check to see if the ProFile is now
recognized. All of the data previously inaccessible should be back and
usable.
For more information about using the ProDOS Exerciser Program, see the
ProDOS Technical Reference manual.
Apple Technical Communications