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Flat-Handler
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1991-07-26
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========================== Flat-Handler 1.3 ==========================
======================================================================
A zany disk filing system, written by Olaf 'Olsen' Barthel of MXM.
Copyright, © 1990 by MXM. Shareware, all rights reserved. No
guarantee of any kind is made that the program(s) described in this
document are 100% reliable. You use this material on your own risk.
============================== Purpose ===============================
======================================================================
The university I am studying at has just got rid of its old IBM
mainframe monster which has been replaced by set of Sun4 Sparc IPC
workstations. Each station has its own disk drive built into the main
unit. Transfer of data to and from the disk is easy if you know how
to accomplish it. Standard 3½" disks can be formatted in vanilla
MS-DOS format (double sided, 9 sectors, 512 bytes each) and read using
MessyDOS/CrossDOS. Unfortunately, `pcfs' is not available on the
machines I am working at, still using `tar' makes it easy to exchange
files between both computers.
The Amiga does not support block mapped files in the same way Un*x
does. My first attempt to read tar archives written to disk would
therefore consist of creating a disk-like file on my harddisk (using
Matt Dillon's fmsdisk.device) and reading the disk-file with tar.
This being not the ideal solution I immediately started writing a
custom filing system to map all block-oriented filing devices to
virtual files.
=============================== Usage ================================
======================================================================
Copy `Flat-Handler' to your L: directory (copy Flat-Handler L:) and
add the supplied `MountList' file to your DEVS:MountList (type
>>DEVS:MountList MountList). After that, the FLAT:-device is ready to
be mounted (mount FLAT:).
Listing `FLAT:' will display something like the following:
MSH 737280 ----r--- Today 16:42:01
DF0 901120 ----rw-- Today 16:42:01
DF1 0 -------- Today 16:42:01
DH0 10948608 ----rw-- Today 16:42:01
DH1 10616832 ----rw-- Today 16:42:01
Each one of these `files' represents a disk-like block-oriented
filing device (which has the same name, only the colon is left out).
You can copy, type, read and write each device just like an ordinary
file. Each read/write call is mapped to a disk access which allows
archiving whole disks with LhArc or diskcopy'ing with the CLI
copy-command. The protection bits refer to the state of the disk
drive and the data media within:
r - There is a disk in the disk drive.
w - The disk is write-enabled.
All the other protection bits are by default cleared (you won't be
able to delete a disk drive, set the `archived' bit or other foolish
bits). The file creations dates are fake, and the file sizes will
never change (never say never: if there is no disk in the approriate
drive the size of a file will drop to zero). The handler itself
supports only the basic command set a simple filing system needs to
supply (read, write, open, close, lock, unlock, duplock, die).
================ Transferring files from/to the Sun4 =================
======================================================================
To transfer files from/to the Sun4 workstation you will need MessyDOS
or CrossDOS and the Amiga implementation of the `tar' program.
The disk format on the Amiga (MSH:, DI0:, etc.) side must be
configured for a double-sided, 80-track disk with 9 blocks per track.
These settings represent the `factory settings' with which
MessyDOS/CrossDOS are shipped, so there is probably no need to change
them.
Now it's time to initialize a disk, this can either be done on the
Amiga (using "format drive msh: name Blank noicons") or on the Sun
(using "fdformat -l").
Here are the basic commands to get tar to create and extract disk
archives (tar offers a lot more options which you will probably want
to study later):
To create an archive:
Sun4: tar -cf /dev/fd0 <Files...>
Amiga: tar -cf flat:msh <Files...>
To extract files from an archive:
Sun4: tar -xf /dev/fd0 <Files...>
Amiga: tar -xf flat:msh <Files...>
To eject the disk from the Sun4 disk drive enter `eject'.
=============================== Author ===============================
======================================================================
This program was written by Olaf Barthel of MXM. All files have been
placed in the public domain. You may freely distribute this material,
even a small copy fee is okay but everything which looks like
commercial distribution is forbidden. Still you may use this material
for software development without giving credit to the original author.
Send new program revisions, comments, bug reports, donations,
unmarried sisters, non-poisoned candy, home-grown palm trees,
horoscopes, promising capital investments, etc. to:
Olaf Barthel, MXM
Brabeckstrasse 35
D-3000 Hannover 71
Federal Republic of Germany
============ Revision history (most recent change first) =============
======================================================================
V1.3 Added support for ACTION_COPY_DIR packet.
V1.2 You couldn't change the current directory to `FLAT:' and
examine the virtual files without having to specify a full
path name (such as `flat:df0'), this has been fixed.
V1.1 Extended release supporting all available block-oriented
filing devices.
V1.0 First simple release supporting only a single disk drive.