[Tutor] EXE Problem

[eryksun]

On Wed, Jun 19, 2013 at 6:58 PM, Alan Gauld <alan.gauld at btinternet.com> wrote:
> On 19/06/13 17:41, Jim Mooney wrote:
>
>> you should use forward slashes. I have no idea why Bill Gates thought
>> backslashes were kewl
>
> Because MS DOS was copying CP/M which didn't have directory paths
> (it was used with 180K floppy disks that stored everything at the top
> level) but did have command options that were indicated by a
> forward slash
>
> DIR /S
>
> was a sorted directory listing etc.
>
> So MS DOS inherited / as an options marker which precluded
> it's later use as a path separator...

CP/M didn't have a hierarchical file system, but it did have up to 16
USER areas. As to / switches, maybe at some point someone confused
CP/M with DEC's TOPS-10, which used switches quite a lot (it even had
SWITCH.INI for defaults). TOPS-10 would have been familiar to many
1970s programmers. Its DIR command had over 70 switches, such as /SORT
(default) and /NOSORT. In contrast, DIR on CP/M used options in square
brackets, such as the following example:

   DIR [DRIVE=B,USER=ALL,EXCLUDE,NOSORT] *.DAT

This would list all files on B: in all USER areas exluding DAT files,
without sorting.

The USER areas in CP/M are reminiscent of TOPS-10 user-file
directories. A UFD was designated by a [project, programmer] number
(PPN), and could have up to 5 levels of sub-file directories (SFD).
For example, DSKB:FOO.TXT[14,5,BAR,BAZ], where 14,5 is a PPN. In VMS
style it's DSKB:[USER.BAR.BAZ]FOO.TXT. In comparison, slash vs.
backslash seems trivial.