Re: HELP: Problem sending in ProTERM -- ProDOS error $4B

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

Rubywand <rubywand@swbell.net> wrote:

> d a r r e n j o h n s o n writes ...
> > 
> > Any help would be appreciated. I've had trouble sending (ZModem,
> > XModem, Kermit, all protocals) from my IIgs using Proterm 3.1. I can
> > send text fine, but if I try to send a JPG or other binary it's a no
> > go. I can receive okay.
> > 
> > Whether that JPG be on a hard drive or diskette, I either get a
> > ProDOS error $4B right away or it gets to the point where it tries to
> > send, gets up to 128 bytes, then quits due to errors.
> 
>      Error $4B is "unsupported (or incorrect) storage type". In this
> case it appears to indicate that you are using a version of ProDOS which
> does not recognize the filetype of a file you are trying to send.

Bzzzt.  Sorry, wrong answer.  :-)

File types and storage types are completely different things.  The
storage type indicates how the file is physically stored on the volume.
The file type defines the data organisation within the file.

See below for a detailed description.

The answer to the problem in this case is almost certainly that the
files Darren is trying to send are "extended" ones, with a resource
fork.  ProDOS-8 programs such as ProTerm cannot access these files.
There is at least one program that can extract the data fork, and you
would need to use this before being able to send these files.  (Note
that this is not a good idea for files that _need_ the resource fork,
such as GS/OS applications.  JPEGs are probably only using it for
something like a user-added comment, custom icon or thumbnail image, or
similar.)

To prove that this is the problem, try sending a known ProDOS-8 file,
such as PRODOS itself, or BASIC.SYSTEM.  These are both "binary" files,
so would prove that it isn't just a text-vs-binary issue.

Now on to the detailed description:


ProDOS has three storage types for data files: "seedling", which is a
file consisting of a single data block, "sapling", which has a single
index block and up to 256 data blocks, and "tree", which has a single
master index block, up to 256 index blocks, and up to 65536 data blocks
(though the total file size is limited to 16 megabytes, so the master
index can only make use of 128 entries).

In addition, there are a few special storage types:

- "Directory" is used to hold a subdirectory.  This is a linked list of
directory blocks.  (The volume itself, including the root directory, has
another storage type, but this cannot be used for an actual file on the
disk.)

- "Pascal area", used on a ProFILE with the Pascal ProFILE Manager to
reserve part of the ProDOS area as one or more Apple II Pascal volumes.
It consists of a single large reserved range of blocks, by convention at
the end of the volume.

- "Extended" was defined by GS/OS.  It adds support for resource forks
and Macintosh directory information.  An extended file has a single
extended key block, which contains the Macintosh directory information
and references to the two forks.  Each fork may in turn be a seedling,
sapling or tree file.

ProDOS-8 does not support Pascal areas or Extended files, and will give
you error $4B if you attempt to do anything with them (with the possible
exception of renaming or adjusting the other directory information such
as dates and access rights).

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