Re: trying to get an Apple II GS going for fun...

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

Astro <wizard@direct.ca> wrote:

> On Tue, 18 May 1999 08:15:00 +1000, mfumu@alphalink.com.au (Bill
> Robbins) wrote:
> 
> >You can change disks by prefixing the subdirectory name with a slash as in:
> >PREFIX /SECONDDISK<RETURN>
> >And you can go directly to a subdirectory within a different disk from the
> >current one in this way.
> >PREFIX /ANOTHERDISK/ANOTHERSUBDIRECTORY<RETURN>
> 
> Do you mean change disks as in separate drives, or 2 disks in the same
> drive?

Either.  Once you've set a prefix, BASIC.SYSTEM will hunt through all
available drives for the appropriate disk name.

There are basically two modes of operation:

(a) Use slot and drive parameters (,Sn,Dn), as with DOS 3.3.

(b) Use prefixes.

These two methods are in general mutually exclusive.

When you first launch BASIC.SYSTEM, it usually has no prefix set and is
operating in traditional slot/drive mode.

Once you set a prefix, slot and drive settings will temporarily override
the prefix, but are not remembered between commands.

Here is an example.  Assume you have a system with two 5.25" drives in
slot 6.  The disk in drive 1 is called /FIRST and the disk in drive 2 is
called /SECOND.  We start without a prefix having been set and drive 1
being current.

CAT              (Shows catalog of drive 1, /FIRST)
CAT,D2           (Shows catalog of drive 2, /SECOND)
CAT              (Shows catalog of drive 2 again - drive was remembered)
PREFIX /FIRST    (We are now in prefix mode)
CAT              (Shows catalog of drive 1, /FIRST)
CAT,D2           (Shows catalog of drive 2, /SECOND
CAT              (Shows catalog of drive 1 again - drive not remembered)
PREFIX /SECOND
CAT              (Shows catalog of drive 2)
CAT,D1           (Shows catalog of drive 1)

Now swap the disks over

CAT              (Tries drive 2 then drive 1, and shows the catalog)

If you want to stop using a prefix and go back to referring to disks by
slot and drive, use the command:

PREFIX /

Note that PREFIX with no parameter just displays the current prefix.  If
no explicit prefix has been set, then it will read the disk in the
current slot and drive and display its name.

If you want to set the prefix to the disk in a particular drive, you can
of course use:

PREFIX,Sn,Dn    (e.g. PREFIX,D2)

As before, this puts you into prefix mode, and if you want to change to
another disk in the same drive, you will have to clear the prefix with
"PREFIX /" or set the prefix again using "PREFIX,Dn".

> Actually, that is an excellent issue: can you access more than 1 drive
> from the ProDOS command line? Or does the system only recognize the
> boot drive [whichever it might happened to have been]. I have external
> 5.25" and 3.5" drives daisy-chained. 

I hope the 5.25" is daisy chained to the 3.5", not the other way around.

Assuming the standard arrangement on a IIgs, you could just use these
commands, and avoid prefixes unless you want to work with
subdirectories.

CAT,S6          (Catalogs the disk in slot 6, drive 1)
CAT,S5          (Catalogs the disk in slot 5, drive 1)

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