Re: Questions on EDASM reloc ($FE) files

In article <nospam-D69CDA.00073011042006@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
In article <JbadncanU4w_OafZnZ2dnUVZ_v-dnZ2d@xxxxxxxxxxx>,
"Michael J. Mahon" <mjmahon@xxxxxxx> wrote:
...........................
There are many more "typed" files now in the world, even the Apple II
world, than Apple "allocated". The vast majority of these files are
stored as "BIN" files, and the actual "typing" resides outside the
file system as file naming conventions and programmed validity checks.

This is a case in which the PC convention

This is not just a "PC convention". The same convention was used in
both Unix and VMS, two OS'es which predated the PC. CP/M borrowed that
convention, MS-DOS inherited it from CP/M and Windows inherited it from
MS-DOS.

of associating file types
solely with a naming convention has proven more adaptable and robust,
particularly in the absence of a central type control authority.

OT: Wouldn't three printable characters provide just 64^3 = 262144
combinations? I thought Windows was fraught with collisions.

That's because people prefer some character strings over others. In
particular, character strings resembling recognizable words are more
popular.

Also: starting with Windows-95 and Windows-NT-4 a decade ago, the
"file type" isn't limited to three characters. Consider for instance
Java source files which by convention are given the file type ".java"
and the compiled class files are given the file type ".class" (in
Windows 3.x, which still had the three-letter filetype limit, this
became ".JAV" and ".CLA").

Also note that starting with Windows-95 and Windows-NT-4, the "file
type" field essentially vanished: the filename no longer contained a
"name" field and a "type" field, but was simply a string of
characters, including the dot character which earlier was used to
separate the "name" and "type" fields. This had some subtle effects:
starting with Win-95 and Win-NT-4 the filenames "filename" and
"filename." became different, because the strings are unequal. In
Win-3.x and MS-DOS the filenames "filename" and "filename." were
considered equal -- either of them was expanded internally into the
8+3=11 character string "FILENAME " with the three blank at the end
denoting the "filetype".

The major advantage of a typeless file system combined with file
types based on conventions in filenames is that it can easily be
overridden. Suppose you want to use your text editor to try to edit
a non-text file - in a typeless file system like Windows or Unix
this is trivial: just give the editor the name of the file you want
to try to edit. In typed file systems, like the Apple II file systems,
the OS will be an obstacle: you'll have to figure out how to make the
OS allow you to edit that non-text file.

-michael

--
----------------------------------------------------------------
Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
e-mail: pausch at stockholm dot bostream dot se
WWW: http://stjarnhimlen.se/
.

Relevant Pages

  • Re: Two Ways To Identify An Idiot Web Developer
    ... use the inherent capability of the file system to sort resources which by ... use converse file naming in this context 'title text - personal identifier' ... description of resources stored on the file system. ... and it has been adopted as convention for good reason. ...
    (microsoft.public.dotnet.framework.aspnet)
  • Re: Auto-update protocol -- a baby step forward!
    ... By convention, update that ... activate it and let it control ... Obviously this is easier if you have some kind of file system on the ... there's no need for contiguous storage if you have an intelligent ...
    (comp.arch.embedded)
  • Re: Source code file names
    ... convention for preprocessing works correctly with either choice. ... The Mac HFS+ file systems are always case preserving (if I ... There is also the unix ufs file system that has always been ... definitely *NOT* the way case sensitivity is handled in Mac HFS+. ...
    (comp.lang.fortran)
  • Re: Ambiguity in SysV IPC keys
    ... >> But not on the same file system. ... The guarantee is in the SUS (quoted in my earlier msg). ... The convention I ...
    (comp.unix.programmer)
  • Re: Types, packages & objects : the good old naming conventions question (without religious ware
    ... not hard-written in our coding standard rules. ... immediately, to say that except in one point, your convention is the ... with derived type from character, but this is the only one case which ...
    (comp.lang.ada)