Re: Apple model history?

[dempson@actrix.gen.nz (David Empson)]

Paul Schlyter <pausch@saafNOSPAM.se> wrote:

> In article <1e8zu2x.1wlb7k31cpyomuN%dempson@actrix.gen.nz>,
> David Empson <dempson@actrix.gen.nz> wrote:
>  
> [Lack of "cd .." command in ProDOS/BASIC.SYSTEM]
>  
> Perhaps the oversight is within the file system?  Does a ProDOS
> subdirectory contain a directory named ".." ????

No.  There is a close equivalent, however: every subdirectory contains a
header record, which includes a link back to the parent directory.

Supporting something equivalent to ".." would require special case code
in the kernel, which knows to follow the parent directory link.

> Perhaps you can do some "surgery" on a ProDOS disk, creating a
> subdirectory entry named ".." and linked to the parent directory?
> If you do, perhaps "cd .." then will work in ProDOS too?

Except that a filename starting with period is illegal.  You would need
to patch quite a lot to support this.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand