Petrov DOS FS  v. 1.14	(C) Petrov Software

   Several years ago I wrote a program allowing you to read and write 360K
PC disks on a BBC B+. Several times I corrected some bugs, made
improvements until I got access to an Archimedes. Now I have stopped future
development of the code because I failed to get any money for it.

   You can freely distribute the DOS FS as *SHAREWARE*. If you like it and
pay me a small registration fee I will return to development of the program
and you'll get free upgrades. If not, you may use the DOS FS only two
weeks.

Below is short description of the DOS filing system:

Before you begin to work with the DOS FS you'll need to do the following:

   1) Check that the disk was formatted under DOS:
   it MUST have EXACTLY two sectors per cluster, 512 bytes per sector and
      12 bits per FAT entry (for example standard 360K/720K format).

   Disks formatted under some later version of DOS have one sector per
cluster. You can still use these disks: manually edit the boot sector of
the disk (for example with NU's PCTOOLS). The byte at offset 13 (&0D) in
the boot sector (track 0, side 0, sector 1) contains the number of sectors
per cluster. You'll need to change it to 2 and write the boot sector back
to the disk (NOTE, that the information on the disk will be lost).  Then
you must CHKDSK /f this disk and delete garbage files if any.

   2) You will need a BBC B (with 1770 or 1772 double density upgrade
installed and sideways RAM), BBC B+ or Master 128/Compact.

To install, perform the following command:

     Master 128/Compact               BBC B/B+
     -----------------------------------------------------------
     *SrLoad DOSFSM 8000 <rom>        *SrLoad DOSFSB 8000 <rom>

            where <rom> is the number of free RAM bank.

    (the two ROM images differ mainly because of different floppy disk
            controller addresses and some OS differences)

   NOTE: You must have 40/80 or 40-track disk drive for 360K DOS disks.

   3) Press <CTRL BREAK> to initialise DOS filing system. Now you can work
	with DOS FS.

Below is a brief description of the DOS FS commands.

   *DOS
	selects the DOS FS as the current filing system.

   *Mount <drive>
	this command forgets all information about the last DOS disk that
	DOS FS used. You must use this command after changing the DOS disk.
	Disk must be inserted BEFORE *Mount is used. <drive> may be 0 or A
	for drive 0, or 1 or B for drive 1. If you use 720K disks or drive
	1 more frequently, after *Mount you can use

	*SrSave DOSFS 8000+<romlength> <rom>

	to store the default values for the disk format and drive number.
	You can then just use *Srload DOSFS and access the disk without
	using the *Mount command; the default values will be those from the
	previous disk. Be careful because you can damage disks with a
	different format if you access them without *Mount.

   *DisMount
	when some errors occurs the DOS FS doesn't flush its cache buffers
	to the disk. This command must be used before removing the disk
	from the drive to ensure DOS FS writes its buffers. I've rewritten
	some parts of DOS FS and now you can be sure that *DisMount is
	needed ONLY if some errors occured (Disk full/write protected,
	etc.), but I still recommend that you use this command.

   *Access <fsp>
	just swaps locked/unlocked state of the file.

   *Cdir
	isn't implemented.

   *Dir <dir>
	works as usual.

   *Lib <dir>
	works as usual.

   *Format
	not implemented.

   *Verify
	not implemented.

How are filenames translated?
   DOS name \WAFFLE\DOCS\INSTALL.DOC corresponds to
   BBC name .waffle.docs.install/doc  (root is not a "$" but just ".")

   IMPORTANT: DOS FS isn't case sensative, so if you SAVE "SomeProg" you
will be able to load it with LOAD "SOMEPROG" or LOAD "SoMePrOg", but
remember that PC DOS requires that all names must be in stored in
capitals!

   *CAT works not only with directories but also with files, for example:
   *Cat .waffle.docs
   will display all files in directory \WAFFLE\DOCS

   *Cat .waffle.docs.*/doc
   will display all files with the DOC-extension in the same directory.

   *Ex and *Info work in the same manner but give more information on
   items.

   *Delete/*Remove supports * and # but removes only the first occurence of
   the matched object.

   DOS FS supports also both Load and Exec addresses so you can, for
example, *Run machine code programs or *Load File to its default Load
address. Unfortunately it doesn't supports file datestamps in this version.
Version 1.14 has the addresses where DOS FS on RISC OS expects them.

   *Rename - unfortunately isn't implemented.

   *Save/*Load/OPENIN/OPENOUT/OPENUP/CLOSE - implemented.

   OSGBPB - implemented except for reading filenames, etc.

-----------------------------------------------------------------

Notes on version 1.14

After repeatedly trying to contact Dimitry Petrov I decided to take DOSFS
over and fix some major problems with it. These are:

OSFILE 5 (read file info) now returns A=0 if the file does not exist
instead of generating an error.

OSFILE 4 (set attributes) returns instead of generating an error.

OSGBPB 5+ returns no data instead of generating an error.

Non-printable characters in filenames are printed as spaces instead of
control codes, so preventing Win95 filenames messing up the display.

The load address is stored and accessed in the catalog in the locations
used by DOS FS on RISC OS for filetypes.

The DOS disk catalog entries hold the file entry information in the
following layout:

    00-07 filename
    08-0A extension
    0B    attribute
    0C-0F load address, b8-b31 in 0C-0E, b0-b7 in 0F
    10-13 exec address, b0-b31
    14-15 spare
    16-17 mtime
    18-19 mdate
    1A-1B start cluster
    1C-1F length

JGH, 12-Feb-1992.

-----------------------------------------------------------------

   DOS FS contains several errors (known to me) but I am still sure you'll
be able to use it without problems.

            Any questions/suggestions, etc. to e-mail:
                      <dpetrov@misis.msk.su>

                          or snail mail:
                              Russia
                          115541, Moscow
                     Kavkazsky Boulevard, 29
                        Bld. 1, Flat 107.

                          Dmitry Petrov

---
 DPetrov@misis.msk.su (Dimitry Petrov)
 Russian ARM Support Group