Computer Installation Guide - Dragon Clan Series/CD1.iso/CDROM/OCD/0CD.DOC

Text File | 1995-12-08 | 23.3 KB | 530 lines

                           0cd CD-Rom Emulator v7.1
                        ---========================---

1. The Problem!
===============----------------------------------------------------------------
Sometimes, a game comes along that looks to be the best game you've ever seen.
Unfortunately, you have only a single-speed cd-rom, and no matter how fast
your pentium 133 goes, the movies and animations looks like a beetle stuck in
glue.

Then you think of the possibility of copying the game into your harddisk, and
playing it off of it, but alas, that probably won't work. The reason for this
is that such games usually check to see if they are actually running from the
cd-rom. The purpose of this check is to make sure that audio tracks on the
cd-rom are available, but mostly it is used as a simple copy-protection check.

It can take a lot of hard work to make it work from your harddisk, and some
times it can't be done; but the main work is to make the program think it is
really running on a cd-rom. So, how do you accomplish that? 0cd is the answer.

2. Introduction to cd-rom emulators
===================================--------------------------------------------
So, what does a cd-rom emulator have to do? Well, the following list gives you
a clue of the task it must fill:

  ■ Appear as a normal MSCDEX driver to any program
  ■ Make one or more drives appear as a cd-rom
  ■ Simulate or "Swallow" all functions that it cannot handle

The simplest cd-rom emulators work by simply installing itself as a MSCDEX
clone and when a program ask, it will answer with correct data to make it
appear as some of your drives are really cd-rom drives instead of normal
harddisks. This way, you can use SUBST to create a virtual drive in the
directory the game is located in, and use the emulator to make it appear as a
cd-rom drive.

"Swallow" means that when a program tells the emulator to start playing an
audio track (example), then the program will say "sure thing" and just go whop
in the memory, doing essentially nothing. The program will be none the wiser
and happy as a clam.

But, some games does more than just tell the emulator to do stuff. Sometimes
it even checks to make sure that the data the emulator is playing with is the
correct ones. For instance, the game may check how many music tracks there is
on the cd, and crash and burn if it is the wrong number. Simple emulators
usually don't know this kind of information, and says "Ehmmm... 0?" or
something like that.

3. The answer - 0CD!
====================-----------------------------------------------------------
0CD is built to solve a lot of these problems, but unfortunately not all. 0CD
is a small resident utility which emulates MSCDEX in a way I have not found in
any other emulator. 0CD installs itself into memory, runs a program or a batch
file, and then cleans up and exits, neat and tidy. 0CD does the following:

  ■ Appear as a normal MSCDEX driver to any program
  ■ Creates virtual drives from directories, making them appear as cd-rom
    drives
  ■ Lets the virtual drives have their own volume label
  ■ Can write protect the cd-rom drive
  ■ Can make the cd-rom drive appear to have 0 bytes free
  ■ Simulates different speed of the cd-rom drives
  ■ Enables audio-through-put
  ■ Can co-exist with mscdex
  ■ Answers intelligently to the following function calls:
    ■ MSCDEX installation check
    ■ Get number of cd-rom drives
    ■ Get bibliographical filename                   *
    ■ Get abstract filename                          *
    ■ Get copyright filename                         *
    ■ Get drive list
    ■ Get device driver list
    ■ Get MSCDEX version
    ■ Get directory entry
    ■ Get descriptor preference
    ■ Get VTOC entry (Volume Table Of Contents)      *
    ■ Absolute sector read
    ■ Device driver requests
      ■ Play audio
      ■ Stop audio
      ■ Head position (chaning)
      ■ Audio channel info
      ■ Media changed
      ■ Get sector size                              *
      ■ Get volume size                              *
      ■ Get device status
      ■ Get audio disk info                          *
      ■ Get audio track info                         *
      ■ Get UPC code                                 *
      ■ Get audio status (playing/paused)

The entries marked with * are saved by a program called RIPCD into a file.
This file is then read back into memory when 0cd is installed. RIPCD reads the
data off the original cd so the data will appear to be authentic.

4. How to use 0CD
=================--------------------------------------------------------------
0CD works by way of command line parameters and is therefore best suited in
a batch file. The format of the 0CD command line is as follows:

   0CD [options] <directory> [<directory> ... ]

Ignore the [options] part for now; we'll get back to it later. The important
part is <directory>. You fill out the <directory> part with a valid directory.
0CD will create a new drive and redirect this drive to the given directory.
This drive will automatically look like a cd-rom to any program that checks
this.

Example:

  0CD C:\TEMP

This command line will tell 0CD to create a new drive. This drive will really
lie in the C:\TEMP directory.

On the 0CD command line shown above, you can also see that the parameter
<directory> can be repeated. This is denoted with [<directory> ... ]. You can
supply up to 8 such parameters at one time to 0CD, creating at most 8 cd-rom
drives. The cd-rom drives can all be directed to different directories or the
same as seem fit. Example follows:

  0CD C:\CD1&2 C:\CD1&2 C:\CD3

Here, 0CD will create 3 cd-rom drives. The first two will be redirected to the
same directory, C:\CD1&2. The third cd-rom drive will be redirected to the
directory C:\CD3.

When 0CD has created all cd-rom drives, and settled into your computer, it
does one of two things:

  if a file called 0CDSTART.BAT (or a user-supplied program file) exists in
  the current directory, 0CD starts it. When execution of this file is
  finished, 0CD unloads itself from memory.

  if the file doesn't exist, 0CD starts up your current command line shell
  (usually COMMAND.COM or 4DOS.COM). When this shell exits, 0CD unloads itself
  from memory.

5. 0CD valid options
====================-----------------------------------------------------------
0CD can also respond to various options on the command line. The options can
be given before all <directory> in between the <directory> parameters, or
after the <directory> parameters, but note that they only take effect on the
<directory> parameters which comes after the options. See the text below on
the -q option to see how this works.

Each option will get it's own subchapter here, for optimal clarity and easier
reference later on.

5.1. 0CD option: -Q
===================------------------------------------------------------------
The simplest option for 0CD is the -Q option. This option tells 0CD to not
print any text on the screen (QUIET operation). Above it was explained that
options only takes effect on any parameters which comes after them, and here
are some examples on that:

  0CD -Q C:\TEMP

This example will not print any text on the screen.

  0CD C:\TEMP1 -Q C:\TEMP2

This example will print text on the screen up to the point it reaches -Q. This
means that you will not notice that two drives has been created, only one
(C:\TEMP1), and you will not see the uninstall message.

5.2. 0CD option: -R
===================------------------------------------------------------------
Earlier, you was told that 0CD automatically starts the file called
0CDSTART.BAT if the file exists in the current directory. If you would like
some other program to be started, you can supply the name of this program to
0CD with the -R option. Example:

  0CD -RC:\NC50\NC.EXE C:\TEMP

Here, 0CD will create a cd-rom drive, and run Norton Commander. When Norton
Commander exits, 0CD will unload itself from memory. You can run .BAT, .COM or
.EXE files or any other file types your current command line shell allows for
(4DOS allows you to run .BTM files also for instance).

5.3. 0CD options: -0 and -W
===========================----------------------------------------------------
If you examine a cd-rom, you will notice two things; the drive is write
protected, and it has no bytes free. To simulate this behavior, 0CD has two
options for this: -0 and -W. the -W option turns on the write protection, and
-0 simulates the "disk full" behaviour of cd-rom drives.

Unfortunately, DOS sometimes sees through the redirection that 0CD sets up,
and when a program or command (like DIR) checks to see how many bytes the
drive has free, it will look at the host drive for the emulated cd-rom drive.
Example:

  0CD C:\TEMP

This will create a new cd-rom drive (like E:) and put it in the C:\TEMP
directory. When a program checks to see how much available space E: has, DOS
will sometimes check the C: drive. To simulate the "disk full" syndrome of
cd-rom drives, 0CD has to make it appear that C: is full. This will in turn
make it appear as E: is full. Also, the disk can be written to. Please note
that even though 0CD will make it appear as the disk is full by reporting 0
bytes free, you can still create files as normal. The "Disk full" messages
comes when a program isn't able to find vacant space on your harddrive, not
when the disk allegedly has 0 bytes free.

If you use this command line:

  0CD -W -0 C:\TEMP

then 0CD will report 0 bytes free for all programs that check this. Also, the
disk has been write protected. Note that drive C: will also report 0 bytes
free, but will not be write protected.

5.4. 0CD option: -S
===================------------------------------------------------------------
Also, if you need to simulate different speed of the cd-rom drives, use the
-s option. After -s, you supply either s, 1, 2, 3, 4, 6 or 8 for the speed,
denoting "Super", single, double, triple, quadra, sexa or octa speed. Super
speed means that the read that the minimal amount of time, and on my P90 the
speed of the cd-rom drive is approximately 9.1 MB/s in super mode.

5.5. 0CD option: -F
===================------------------------------------------------------------
If a function call to the simulated cd-rom driver has no data to operate on,
or no valid data to return, 0cd simply returns with all flags and values set
to success, even though the data it returns may not be valid. If you want
the driver to return failure codes instead, use the -F option.

5.6. 0CD option: -A
===================------------------------------------------------------------
If you come across a really stubborn game, try using the -A option for
alternate cd-rom driver simulation. In fact, the -A option will make 0CD work
like another cd-rom emulater that is available, and that is called FAKECD 1.0.
One game you must use -A with is Worms from Team 17. The -A option effectively
disables some of the cd-rom driver functions, and ignores any cd-rom data which
has been read into memory. Use this only as a last resort.

5.7. 0CD option: -I
===================------------------------------------------------------------
By using the -I option you can instruct 0CD to simulate three different types
of cd-rom drives. Physical (like a harddisk), substed, or remote (network
and cd-rom drives). Default is to simulate a remote drive.

The option is followed by a single digit which has to be 0, 1 or 2, like this:

  0CD -I1

The three different digits means the following:

   -I0 = Physical
   -I1 = Substed (like a subst and then a cd-rom emulator on top)
   -I2 = Remote (network or cd-rom)

5.8. 0CD option: -D
===================------------------------------------------------------------
If you have access to the cd-rom when you copy or start the game, use the -D
option to read back data from a file. The file should contain valid cd-rom data
and if you look in chapter 6, you will see a way to steal the data from the
original cd-rom. This way, 0CD will emulate the original cd better than without
the data.

5.9. 0CD option: -M
===================------------------------------------------------------------
The -M option instructs 0CD to co-exist with mscdex the best way possible.
The -M option needs a parameter, a single digit which can be 0, 1, 2 or 3.
The different meanings of the digits are:

   -M0 = 0CD will NOT co-exist with MSCDEX in any way (this is default)
   -M1 = 0CD will enable audio through-put
   -M2 = 0CD will co-exist with MSCDEX, but audio through-put is disabled
   -M3 = -M1 + -M2

Audio through-put means that the program can start and stop audio tracks on
the first cd-rom attached to the system as normal. This means that for games
that enables you to listen to music from the cd, you can just pop in any
cd which you have lying about and listen to it. 0CD will take over and respond
to any communication with the cd-rom drive, but will leave all the aspects of
audio to the original MSCDEX driver.

5.10. 0CD option: -V
====================-----------------------------------------------------------
The -V option shows version information about 0CD. This is primarily intended
as an identification utility when you report bugs.

6. Advanced
===========--------------------------------------------------------------------
If you have to copy a really tough game onto your harddisk, you need to use
the supplied utility called RIPCD. RIPCD reads a small portion of the system
information available from a cd and stores it in a file on your harddisk. When
0CD later on loads itself into memory, you can instruct it to load the file.
When a program then asks 0CD for some of this information 0CD can supply it
with the same information that the original cd would have produced.

RIPCD takes two parameters, and the command line format is as follows:

  RIPCD <filename> [<cd-drive>]

The <filename> parameter names the file to put the information in, and the
<cd-drive> parameter identifies the cd-rom drive. You don't need to identify
the cd-rom drive if you only have one drive in your system. If you have more
than one drive, you need to supply this parameter.

RIPCD will then read the data and put it in the file. Example:

  RIPCD CARPET.DAT E:

RIPCD will here read the system data from the cd-rom in drive E:, and put it
in the file called CARPET.DAT.

To make 0CD load the data back into memory, use the -D option. Example:

  0CD -DCARPET.DAT D:\CARPET

Notice that the -D option is supplied BEFORE the <directory> parameter. The -D
option will then work for all such <directory> parameters which comes after
it. To make a drive have no data, use an empty -D option. Example follows:

  0CD -DCD1.DAT C:\TEMP C:\TEMP -D C:\TEMP

Here, 0CD will create three cd-rom drives. The first two will have system data
available from the file CD1.DAT, but the third cd-rom drive will have no
system data available. You can supply different system data files for each
drive if you want to.

RIPCD needs the program CRUNCH.COM to be in the same directory as the
RIPCD.EXE file itself, so don't move this file.

If you for some reason need to make a cd-rom with a specific volume label,
or you'd like to simulate how many audio tracks the cd has, but don't have the
original cd nearby, use the MAKECD program. The MAKECD program will create a
dummy cd with most normal values, but let you enter the volume label and how
many audio tracks there is on the cd. MAKECD needs only the filename of the
file to create.

7. Known problems
=================--------------------------------------------------------------
0CD is far from perfect. Some problems are made to be so stubborn that 0CD
will not be able to respond in a satisfactory way. One reason for this is that
the ABSOLUTE READ SECTOR function call is off course not implemented in 0CD.
If a program uses this function call to read system data and check for the
original CD, 0CD will come up short. Usually, this problems crops up when you
use cd-rom identification utilities.

Here is a list of games and programs it has been tested and found to be
working with:

  MechWarrior 2
  Magic Carpet 1
  Magic Carpet 1: The Hidden Worlds
  Magic Carpet 2: Netherworlds
  Fade 2 Black
  Command & Conquer
  QCD (cd-player that comes with SB16 system)
  Norton System Information
  Worms (use the -A switch, and no cd-data, or use the audio through-put)
  ScanCD from Corel Corporation

Apart from these games, it hasn't been tested on any other products. As you
can see for yourself, the list is far too short to say anything conclusive
about the quality of 0CD. So far, it has worked fine, but there are probably
some problems with it yet to be found.

8. Disclaimer
=============------------------------------------------------------------------
In this document I have talked a lot about copying games onto harddisks, and
avoiding copy protections and such stuff. As you already know, this is
illegal, and I do not encourage such behaviour. The reason I made this utility
was to make my computer able to smoothly play some of the newest games
available, not to make it possible to rip and distribute pirated games. I hope
that some people will enjoy this utility, and not blaim the "weapons" maker
for the "deaths" it make.

9. Who am I?
============-------------------------------------------------------------------
My name is Lasse Vågsæther Karlsen, and you can reach me on internet on the
following email address:

  [e-mail]

10. Why would you get in touch with me?
=======================================----------------------------------------
If for some reason you have a program 0CD doesn't run with, tell me about the
problem. Give me your best shot at the reason for the failure, and a probable
remedy for it. If I can fix the problem, you will get a 0CD that works with
your software, and 0CD will get better. In the end, 0CD may be usable for a
much larger range of software than it is today.

11. The source code for 0CD
===========================----------------------------------------------------
As you can see, the source code for 0CD follows this package. Always when I
get a new utility, I feel a lot safer when the person who wrote it supplies
the source code as well. Because of this, I supply the source code as part of
this package. It is the complete source code, with the exception of the source
code to CRUNCH.COM. This program is part of another package I have created,
and is available upon request (Package+Source code that is). So tinker around
and look at the source code, or even modify it.

12. Tips
========-----------------------------------------------------------------------
If you encounter a stubborn game, try combinations of the options. Sometimes,
a game will not work when you feed it with original data from the cd-rom,
but may instead work with a subset of the data and functions.

13. Revision history for 0CD
============================---------------------------------------------------
; Revision 1.36  1995/12/04 00:56:07  Lasse
; Version 6.6; Now works with worms too, and simulates the following new
; device requests:
;   Play
;   Stop
; also, the AudioStatus function has been augmented to react on the Play
; and Stop functions, and the HeadLocation function will return different
; values, as though the cd was playing or moving around.
; Also, the -a option will make 0cd simulate FakeCD.
;
; Revision 1.35  1995/12/03 02:35:45  Lasse
; Version 6.5; Fixed the root-directory subst problem which came back :(
;
; Revision 1.34  1995/11/26 09:46:54  Lasse
; Version 6.4; Fixed several bugs with the DiskFree function
;
; Revision 1.33  1995/11/16 06:36:22  Lasse
; Fixed a bug in the makecd program, and an inconsistency in 0cd
;
; Revision 1.32  1995/11/16 06:14:39  Lasse
; Put Decrunch into 0cd.asm for maximum distributability
;
; Revision 1.31  1995/11/16 06:04:28  Lasse
; Version 6.2
;
; Revision 1.30  1995/11/16 05:24:59  Lasse
; Commented all code; Done some minor cosmetic changes, tidied up the
; code a bit
;
; Revision 1.29  1995/11/14 22:04:22  Lasse
; If last character in directory was \ then redirection failed; fixed!
;
; Revision 1.28  1995/11/14 21:57:59  Lasse
; Removed the "Unmangling" of filename
;
; Revision 1.27  1995/11/14 21:46:19  Lasse
; Version 6.2; Fixed so that magic carpet works; Fixed so that DiskFree(d:)
; where d: is a cd-rom now returns correct data
;
; Revision 1.26  1995/11/14 19:50:33  Lasse
; Bug in previous revision concerning the drive letter in speed messages;
; fixed
;
; Revision 1.25  1995/11/14 19:48:43  Lasse
; Fixed so that speed message included correct drive letter
;
; Revision 1.24  1995/11/14 19:29:30  Lasse
; Version 6.1; Super speed emulation enabled
;
; Revision 1.23  1995/11/14 19:02:11  Lasse
; Updated the usage message, and renamed VTC to data
;
; Revision 1.22  1995/11/14 18:51:36  Lasse
; Version 6.0; Now simulates speed of cd-rom; Also read sector 16 (system
; data)
;
; Revision 1.21  1995/11/12 21:52:52  Lasse
; Version 5.0; fixed a couple of bugs with the audio track information
;
; Revision 1.20  1995/11/12 08:14:22  Lasse
; Version 4.1
;
; Revision 1.19  1995/11/12 08:09:58  Lasse
; Removed some old dummy-stuff
;
; Revision 1.18  1995/11/12 06:44:56  Lasse
; Audio Status now responds music paused; fix necessary for MechWarrior 2
;
; Revision 1.17  1995/11/12 03:39:43  Lasse
; Fixed the return to directory bug
;
; Revision 1.16  1995/11/12 03:24:55  Lasse
; Bug-fix; couldn't supply more than name.ext, no dir to run
;
; Revision 1.15  1995/11/12 03:21:29  Lasse
; Version 4; supply name of program to run
;
; Revision 1.14  1995/11/12 02:34:58  Lasse
; Fixed so that it reads audio data also
;
; Revision 1.13  1995/11/11 22:51:03  Lasse
; Fixed so cd-roms could be redirected to the root of a drive
;
; Revision 1.12  1995/11/11 22:48:52  Lasse
; Fixed a bug which caused strange symbols in 'dir' listings
;
; Revision 1.11  1995/11/11 22:39:32  Lasse
; Fixed so it didn't automatically write protect cd-roms unless the user
; asked for it
;
; Revision 1.10  1995/11/11 20:50:50  Lasse
; DiskFree function now clears carry flag
;
; Revision 1.9  1995/11/11 20:44:24  Lasse
; Version 3.1; added option to supply name of .vtc file
;
; Revision 1.8  1995/11/11 20:15:29  Lasse
; Returns dummy filenames, and uses CD0.VTC - CD7.VTC instead of DIR.VTC
; so that the same directory may be used for different cd's.
;
; Revision 1.7  1995/11/11 05:55:23  Lasse
; Fixed so it reads the VTOC into memory and returns it upon request.
;
; Revision 1.6  1995/11/10 23:14:47  Lasse
; Fixed the volume label bug that appeared in the last revision.
;
; Revision 1.5  1995/11/10 23:05:40  Lasse
; Fixed a bug when checking more than 8 drives past the first emulated
; cd-rom drive.
;
; Revision 1.4  1995/11/07 22:15:01  Lasse
; Version 2.0
;
; Revision 1.3  1995/11/07 22:13:19  Lasse
; Now saves current drive and directory and restores them when the sub-
; process exits. Also has self-installed check code now.
;
; Revision 1.2  1995/11/07 21:50:29  Lasse
; Moved all string procedures into 0cd.asm itself. Tidied up some of the
; code. Replace the uppercase functions. Fixed so that the GetDirEntry call
; to MSCDEX will go through (possibly returning garbage, but...) and some
; other stuff.
;
; Revision 1.1  1995/11/07 20:15:56  Lasse
; Initial revision