Date   : Fri, 20 Mar 1981008:48:00-MST
From   : Bob Clements <CLEMENTS@BBNA>
Subject: Kludgey patch in case of panic

I just had the problem of reading files under 1.4 CPM which
had been written under 2.x CPM into a NON-ZERO user
area. My CPM didn't find the files -- said "NOT FOUND".
I'm sure someone else has solved this problem too, but just for
the record, here's a quickee patch.

Addresses are for a 16K CPM (starts at 2900). Modify for your
size of system.

LOC    OLD     NEW
3690   E5      00

369C   C1      7E
369D   0A      E6
369E   96      80

3708   E5      00

Then restart CPM in such a way that it doesn't re-boot itself and
overwrite your patch, such as Go to 2903.

Put the disk with the non-0 user area in the drive and type DIR *.FOO .
You should see all the files, even if not named .FOO . Then type
ERA *.FOO . This will make all the files be in user area 0, NOT make
them erased. Then re-boot your CPM to get all those kludgey patches
out of there, and do a DIR to make sure you won. [You did do all 
the above on a COPY of the disk, didn't you?]

FYI, the patches at 36xx make the CPM lookup routine see all files
that aren't deleted, regardless of file name. The patch at 3708 makes
the delete routine put "user 0 undeleted" into the FCB instead of
"blank disk, deleted (E5)".

/Rcc