Re: ProDOS commands

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

Simon Williams <ludditetech@mac.com> wrote:

> Is there a prodos command that will list all volumes currently online?

There is a call in the ProDOS kernel which does this, but no standard
command in BASIC.SYSTEM to make use of it or to display the output in a
readable format.  I expect that someone may have written a third-party
add-on command to do this.

> or at least identify the volume in a specific slot/drive...

What is wrong with CAT,Sn,Dn?

You can also use PREFIX,Sn,Dn followed by PREFIX by itself (which prints
the current prefix).

If you are doing this from inside a program, you need to use an INPUT
statement after issuing the second PREFIX command.

> ...and what about VERIFY ???
> how is that supposed to work?

I haven't used this one enough to remember the details.  Where's that
manual...

VERIFY's purpose is to confirm that a file exists.  It doesn't open the
file and verify its contents.

 If I VERIFY a valid pathname it does
> nothing, even if I append an incorrect slot & drive number.

If you specify a slot and drive in conjunction with a full pathname, the
slot and drive parameters will be ineffective.  They cause ProDOS to
look at the specified slot and drive first, but it will then search
other drives to locate a volume of the specified name.

If you use a partial pathname in conjunction with the slot and drive
parameters, the filename is expected to be relative to the root
directory of the indicated slot and drive.  If you have set a prefix, it
might override this.  You can use PREFIX / to clear the prefix and
return to pure slot-and-drive operation.

> If I VERIFY an invalid pathname it kindly tells me PATH NOT FOUND. And if
> I try to VERIFY slot & drive, with no pathname, I get COPYRIGHT APPLE
> COMPUTER -- what does it all mean?

That may be a bug.  Which version of BASIC.SYSTEM are you running?

If you don't have a prefix set, then VERIFY,Sn,Dn should verify the root
directory of the volume in the specified drive.  I've never used this
particular variation, as there are better ways of doing this.

-- 
David Empson
dempson@actrix.gen.nz