>Guide
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DiscInfo 1.05                                       --------------------------
                                                     This program is FREEWARE
Version date : 05 Jun 1992                          --------------------------

----------------
- Introduction -
----------------

DiscInfo provides extensive information about discs that reside under a
FileCore based filing system.

The information given by DiscInfo is quite 'involved', and requires a suitable
understanding of how a FileCore filing system stores its files on a disc. This
understanding may be gained from the Programmer's Reference Manuals and any
additional documentation on FileCore filing systems.

This guide does not attempt to explain FileCore concepts.

DiscInfo is only suitable for discs that reside under a filing system based on
FileCore (like ADFS and RAMFS). It is also really only suitable for E format
discs. Though disc record parameters will be accessed, the map of an old (D/L)
format disc is never accessed, as its structure and purpose are both very
different from that under the E format.


-------------------------
- Using the application -
-------------------------

To start up DiscInfo, double-click on the '!DiscInfo' icon.

It will install itself on the icon bar, and clicking MENU on DiscInfo's icon
pops up the main menu, giving the usual 'Info' and 'Quit' options, and others,
which will be discussed further on.

Clicking SELECT or ADJUST will access the current disc and pop up the disc info
window (see below for details).


-----------------
- The main menu -
-----------------

This menu, popped up by clicking MENU on DiscInfo's iconbar icon, contains a
number of icons (some of which lead to submenu's/windows). The functions of the
icons will be discussed below.

The main purpose of the main menu is to provide access to DiscInfo's control
window (via the 'Control' icon), which contains (in groups) most of the
available options and controls.

-----------
| Control |
-----------

Gives access to DiscInfo's control window, which contains most of DiscInfo's
options and controls, divided into groups.

Clicking on this icon will make this window permanent (but it can be closed
again by clicking on its close icon).

Several types of icons appear in the control window :

- Toggle icons. These are square, and clicking on them switches the
  corresponding option on (red square in its middle) or off ('closed' box).
- Radio icon sets. Icons in these sets are diamond shaped, and act like the
  toggle icons, but only one of them may be on. Switching any one on will
  switch off all the others in the same set (hence the name 'radio' icons).
- Writable icons. These are square icons with a border and a white background,
  in which you may click an subsequently enter a value or text.
- Button icons. These are round, and clicking on them executes some function.
  They do not change their appearance when clicked on.

The functions of the icons in the control window are discussed below. Icons are
identified by giving their 'path', i.e. group name (name on the border
surrounding the group), if appropiate followed by sub-category (medium grey
heading), followed by the icon's own name, seperated by '|'s.

\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
 Disc specification | Filing system
////////////////////////////////////

The filing system under which the disc to be examined resides, may be entered
in this writable icon.

Further below are button icons which, when clicked, will set it to a known
FileCore based filing system.

\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
 Disc specification | Drive number
///////////////////////////////////

The drive number of the disc to be examined may be entered in this writable
icon. A drive number may be from 0-3 ('floppy' drives) or 4-7 ('hard disc'
drives).

Further below are button icons which, when clicked, will set it to a specific
drive number.

\\\\\\\\\\
 Log file
//////////

Below this are two icons : a toggle icon and a writable icon.

The toggle icon switches on/off log file generation during an examination of a
disc. On completion, the log file will contain all information contained in the
disc's disc record and its map. It will also contain a complete list of all the
objects found in the map. All objects are listed by their disc address and
length, and file/directory objects also show the file number.

The filename of the log file (default 'RAM:$.Log') may be entered in the
writable icon.

The log file may be an invaluable aid in recovery of disc files. It is easy
to write a simple program that accesses it. Using the additional information
present in a directory (i.e. file numbers and sector offsets), it is then
possible to recover lost files, e.g. after a hard disc crash.


------------------------
- The disc info window -
------------------------

The disc info window will be popped up after a succesful examination of the
selected disc (i.e. after clicking SELECT or ADJUST on the iconbar icon).

Most of the textual information in this window reflects direct or deduced
information from the disc record, and requires no further explanation. Refer to
the PRM's and other documentation to figure out what they mean.

The exceptions are discussed below.

- 'Map found at &ssss-&eeee'

This shows exactly where the map was found. This is usually 'half way' on hard
discs, or at the very start for floppy discs. The addresses given may be
directly used to extract the map with <FS>_DiscOp 1, should you want to examine
the map more closely.

- 'Files/dirs', 'Free space', 'Defects'

These show how many bytes were found to be allocated in total to these kinds of
objects. The total of these three figures (shown after 'Total') should be equal
to the disc size (see 'Disc size').

The radio button icons before these icons select whether or not the respective
kind of object is shown in the graphical representation of the map (see below).

- The bunch of '+'s and '.'s

This shows the disc's map, graphically represented by an array of cells.

The whole array represents the entire disc space, column after column from left
to right. The disc address range covered by the array is shown at the top left
of the cell array, e.g. the first (start) address is at the 'top' of the top
left cell, the second (end) address is at the 'bottom' of the bottom right
cell.

A single cell represents the number of bytes shown after 'Bytes per cell'. On
large discs (e.g. hard discs), there are far more allocation units than cells,
so each cell, representing several allocation units, may be 'occupied' (in some
order at sub-cell level) by several kinds of object at the same time. For small
discs (e.g. floppies), a cell will represent a single allocation unit (the
'large allocation unit' to be exact, or the sector size when this is smaller),
and some cells will be left unused.

The radio buttons before the 'Files/dirs', 'Free space' and 'Defects' info
icons select which kind of object(s) is/are shown. Clicking SELECT on one of
them will cancel all other selected object kinds, while clicking ADJUST will
not (i.e. this allows multiple selections).

When only one kind of object is selected, a '+' will show in a cell (partially)
occupied by this kind of object, else a '.' is show. When two are selected, a
'1' is shown in cells occupied by the first kind of object ('Files/dirs' first,
then 'Free space', then 'Defects'), a '2' for the second, and a '3' for both.
When all three are selected, '1'=first only, '2'=second only, '3'=first and
second, '4'=fourth, '5'=first and fourth, '6'=second and fourth, and '7'=all
three (this clearly shows why you should only really select one !).


-----------------------
- Memory requirements -
-----------------------

!DiscInfo runs in a minimum amount of memory when dormant. Prior to examining a
disc, all available memory is grabbed, and released again on completion of the
operation. A small amount, however, will be kept to store disc map information.
This is released again on closing the disc info window.

NOTE : The amount of extra memory needed (i.e. the amount you must keep free)
varies, depending on the size of the disc map. Usually, you will not have to
worry.


-----------
- The end -
-----------

If you have praise, complaints, comments, bugs(!), or anything else to offer
me, do not hesitate to write to

John Kortink
Middelhuisstr. 17
7482 EL Haaksbergen
The Netherlands

or send email to kortink@cs.utwente.nl

New versions of the application are available from the same address : just send
1 to cover postage and a self-addressed envelope containing a 3.5" disc.

It is not very likely though that many new versions will appear. !DiscInfo
serves a simple purpose, and does it well, and this will remain to be so.

Happy disc examinations !!!

_______________________________________________________________________________

!!! NOTE !!!

You may NOT change this application or use ANY part of it in other products
without my approval. You may spread it freely (with *ALL* files included), but
not for any profit. This software is provided 'as is'. Using it is entirely at
your own risk.

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