25 Nov
2001
25 Nov
'01
11:46 p.m.
Correct save for CP/M only used 0-15 for the V2.x and ZCPR extended
this to 0-31. The areas were not protected directly from each other but
were logically seperate. It made file management easier on a logical
volutme without a heirarchial (non flat) directory structure.
FYI: the byte used to carry user is the 0th of the 32 bytes in a directory
entry. Values (byte) 0E5h, 0FFh, 0FEh are reserved for erased(e5),
deleted(Fx).
To add to this the high order bits of the file name 8.3 are reserved for
control/ Those bits control RO, system(invisible) and other status
items. All file names were 7bit ascii. ZCPR and other utility programs
extended and used those bits for things like archive status abd public
files(accessable from any user #).
Allison
-----Original Message-----
From: George Leo Rachor Jr. <george(a)racsys.rt.rain.com>
To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
Date: Monday, November 26, 2001 1:45 AM
Subject: Re: Inaccessible CP/M programs in Altair32
I'm not an expert in Altair CP/M but I do remember
one other aspect. It
wasn't password protection but I do remember the concept of differnt user
#'s. It wasn't complicated but somthing like user #'s 1-8. Once you
were that user I seem to remember only the files belonging to that user
showing up...
Might be a dead end... Just a thought...
George Rachor
=========================================================
George L. Rachor Jr. george(a)rachors.com
Hillsboro, Oregon http://rachors.com
United States of America Amateur Radio : KD7DCX
On Sun, 25 Nov 2001, Jim Battle wrote:
> At 10:06 PM 11/25/01 -0500, you wrote:
> >Hi:
> >
> > I'm making progress with using CP/M under Altair32, but I have
> > one newbie
> >question since I don't have much experience with CP/M.
> >
> > The disk image I have shows one program in the directory,
> > STAT.COM. Running
> >STAT tells me that there is about 167k free (on a 330k disk). Looking at
the
> >disk image file with a hex file editor reveals
that there's more
programs on
> >the disk.
> >
> > I seem to remember something about password protection on a
CP/M
> > disk. How
> >do I get around this so that I can see what else is on this image?
>
> It isn't password protection. Files can be marked as "system" files,
so
> that they don't show up when you do a "DIR". I think "STAT *.*
$DIR"
will
revert all
hidden files back to normal.
-----
Jim Battle == frustum(a)pacbell.net