Aucbvax.1455
fa.info-cpm
utzoo!duke!mhtsa!ucbvax!PLATTS@WHARTON-10
Sat May 30 17:51:36 1981
Search first/next question
Concerning the problems using search first/next to muck
around with files... I spent some time around 4 or 5 years ago reading
a disassembled version of the CPM 1.4 BDOS, and as I remember it:
Search First was used to initialize a counter into the directory
area, and to find the first occurance of a ambiguous filename.
Search next just kept up the search without reinitialization.
As CP/M would use the current DMA area for directory storage, and
not touch that counter elsewise, as long as you don't mess up
the DMA area (by perhaps switching DMA areas for other IO, then switching
back), you'd be OK using other BDOS calls. But if you mess up the
current DMA area, since the next search continues within the current block
(in all likelyhood, since directory entries are stored 4 per sector),
it'll get all confused when looking at "smashed" filenames (FCB's)
-----------------------------------------------------------------
gopher://quux.org/ conversion by John Goerzen <
[email protected]>
of
http://communication.ucsd.edu/A-News/
This Usenet Oldnews Archive
article may be copied and distributed freely, provided:
1. There is no money collected for the text(s) of the articles.
2. The following notice remains appended to each copy:
The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996
Bruce Jones, Henry Spencer, David Wiseman.
