kamath@reed.UUCP (Sean Kamath) (07/17/87)
if you have an enhanced //e, just reboot. Enhanced //e's show "Apple //e"
at the top of the screen, unenhanced ones say "APPLE ]["
The EOF of a file on an Apple is a NULL, and inverse @ signs are displayed
when you try to show a control @, which is ascii 0. If you don't believe
me, type HOME:POKE 1024,0 This puts a 0 in screen location 1,1 or 0,0
depending on how you measure it. Ever wonder why after typing GR then TEXT
you got all those inverse @'s? It's because black is 0.
Anyway, almost every word processor I know of read a file until they hit the
first zero. Things like COPY ][+ keep looking at a file until there are no
more sectors allocated to it. If you try to read it with a small Applesoft
program like:
5 ONERR GOTO 60
10 PRINT CHR$(4);"OPEN FOO"
20 PRINT CHR$(4);"READ FOO"
30 INPUT A$
40 PRINT A$
50 GOTO 30
60 PRINT CHR$(4);"CLOSE FOO"
you will only see up to the first null, because DOS ad ProDOS sees that as
an EOF and gives an error (hence the line 5).
So, you can fix this easily from a disk zap program such as in copy ][+ by
loading in sectors (follow file from the sector zap menu) until you see the
inverse @'s. then change them to '~' or some such so you know they are not
to be there. typically there is only one @. BTW, this is why, if you have
a 100 sector text file, you delete a lot of the text and save it over the
old one, even though the new file only contains 20 sectors it still says it
uses 100. You can easily recover a lot of a text file this way, because DOS
only writes up the the first EOF as well, hance everything after it is safe.
(until it get's overwritten!)
Just thought you all should know. . .
Sean Kamath
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