wmartin@ut-ngp.UUCP (12/04/87)
Last week I posted a note about losing an Excel file - although
the file remained intact as far as my disk sector editor was
concerned, Excel could not read it without crashing.
A few people sent me mail, saying that they had had
that same problem and requesting that I send the Excel
file format if I find it out. I haven't (nobody volunteered it,
anyway), but I did a little experiment, saving a file in all 4
Excel formats:
File Time Preserve Readable
File Size to Read Formats & via Sector
Type (char) In Formulas Editor
Excel 16830 5.91 sec Yes No
SYLK 16392 27.22 Yes Yes
WKS 14370 23.39 Yes(mostly) No
Text 3236 13.75 No Yes
By "readable" I mean you could crank up Fedit and read the numbers
straight off the screen. The SYLK format is documented in various
Microsoft manuals.
The results imply that if you have a database that is very
important to you, you might want to keep it in SYLK or Text
format in case Excel decides to make it unreadable.
--
Wiley Sanders, Civil Engineering Dept, UT-Austin
secret NSA CIA anti Soviet Iran terrorist nuclear drug decoder ring
- take THAT, NSA line-eater!rick@uwmacc.UUCP (the absurdist) (12/08/87)
I recently had a user bring in "my only copy" of an Excel
file that could no longer be read. A little work with
some disk utilities showed that the problem was that the first
sector had gone bad. I made a sector copy of the disk, getting
a "legal" file that would start Excel. However, Excel immediately
claimed that "This is not a saved Excel worksheet."
Microsoft refuses to document their file formats (boo!).
Lotus Corp. does (yeah!). It occured to me that the two
were probably similar in intent, and that the Lotus 123
format keeps no real data in its header; instead it has
all the settings for print ranges, graph types, etc. So
I tried replacing the bad sector with the first sector of
a good Excel worksheet of similar size. Voila! All the
data came back. I advised the person to PRINT OUT their
data, back the thing up, and then reset all their ranges.
As far as I know, that worked fine.
The Lotus 123 format is documented in a book by Lotus Corp.,
called "Lotus File Formats for 1-2-3, Symphony and Jazz."
It's published by Addison-Wesley. Version 3 of Lotus
will have a revised file format, and they are going to
publish that one, too. If you're really worried about
your data, keep it in .wks format, not Excel native format;
you can preserve just about all the worksheet settings,
and still decode it. On the other hand, keeping a set
of BACKUPS together with a PAPER audit trail is better yet.
("No backup? Well, can you can reconstruct the data from
the bills and receipts?" "Oh, no, we threw those all out."
"AAAAUGGGGHH!")
--
Rick Keir -- all the oysters have moved away -- UWisc - Madison
"Watch the skies...."