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Jaguar Developer Weekly        August 11, 1995              Vol.1, No.8
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Jaguar ProController
--------------------
Scheduled to begin production in September, the Jaguar ProController is
an enhanced version of the standard Jaguar joypad that is designed
especially for games that demand more control than a standard
three-button controller.

The ProController features three new primary fire buttons labeled "X",
"Y", and "Z" to complement the "A", "B", and "C" buttons from a standard
joypad.  Another new addition is a pair of "Left" and "Right" direction
buttons at the top of the controller.

From your Jaguar programs, reading the new buttons is very simple,
because they map directly to keys on the numeric keypad, as follows:

X = "9"
Y = "8"
Z = "7"
Left = "4"
Right = "6"

To see if the "X" button is pressed, for example, you simply check the
same bit as you would for the "9" key on the keypad.

We'll have more information about the Jaguar ProController, including
developer availability, in an upcoming issue.



New Jaguar System Include Files
-------------------------------
There is a new update to the standard Jaguar System Include files
(JAGUAR.INC for MADMAC and JAGUAR.H for GCC).  This update corrects a
few typos from earlier versions and adds new definitions:

• The definition of the LFU_XOR blitter logic mask has been corrected.
Previous verions had two bits reversed.

• There are new definitions for masks to aid in reading the new Jaguar
ProController.

To update your development system, download the archive SOURCE.ZIP and
extract the new files.



New BBS Number
--------------
The new Atari Software Development BBS is now up and running as a two
line system.  The new number to call for both lines is (408) 541-9164.
The old phone number is no longer active.  The new line does not go
through the rest of Atari's phone system, so it should be more reliable
for those callers who have had noise-related connection problems in the
past.


Don't Use More Than 1 File Per Track With Jaguar CD Emulator
------------------------------------------------------------
It is highly recommended that you specify only one file per CD track
when using the Jaguar CD Emulator program on the Falcon030 computer.
This file should be exactly the same as what would be used when you
actually master a CD, complete with track header and tailer, and 64-byte
sync markers (a unique 4 byte pattern repeated 16 times) in front of
each distinct piece of data (such as contents of the individual files
used to create the track file).

The emulator allows multiple files per track, but this causes certain
differences in behaviour compared with an actual CD.  These differences
are unavoidable, and can cause major problems when you later try to
master a real CD.  Using just one file per track means that the
behaviour of the emulator will be as close as possible to a real CD.

Here's a basic explanation of why using multiple files per track in the
emulator is a bad idea.  The emulator reads data from the hard disk at
the same time it sends data to the Jaguar.  The timing for this is very
tight, and when it gets to the end of one file, it doesn't have enough
time to start reading from the next one.  It must send the data on time
or it will cause an error in the I2S connection to the Jaguar.  To avoid
this, it sends zeroes until it can start reading the next file.  The
result is that file sizes get rounded up, which doesn't happen when you
combine files together into a raw track file to master a CD, and this is
where things go wrong.

If you have a track with 10 files that are 2000 bytes each, then
normally when you create a track file for CD mastering, you'll end up
with about 20000 bytes of data (we still have to add the sync markers,
track header, and track tailer).  With the emulator, because each file's
length is going to be rounded up, it will be necessary to read about
200000 bytes to get all the data in one step (10 data files, plus the
files for the track header and tailer).

Obviously if your track lengths are so dramatically different, the
position of the data from each file is going to be quite different as
well.  This will almost certainly break something in your program.

In order to support multiple files in a track using the emulator, you
basically have to read each file's data individually, using the file
position specified in the header file created by the emulator.  (The
padding is taken into account when the emulator creates the header.)
This allows you to ignore the extra padding, but it is quite inefficient
when reading many small chunks of data.  Also, when you later create a
real CD, the time codes given in header file will no longer be correct.
The end result is, you'll end up with your data in dramatically
diffferent places on the CD, and your program won't work.

The solution to all of these problems is to use only one file per track
in the first place.  The one file used for each track should be ready
for CD mastering.  This way, the difference between reading the data
from the emulator or from a real CD will be negligable.  Furthermore,
when you are ready to master a CD, you won't have to do anything
additional to prepare the files.



Multiple Sessions on Jaguar CD
------------------------------
The ideal Jaguar CD has a total of two sessions.  Session #0 contains
only standard Red Book audio tracks.  Session #1 contains your boot
track as well as all your other code and data files.

Using additional sessions may be useful at times during the development
process, but serves no real purpose on a production disc.  Using more
sessions also increases the time needed to master the disc, as well as
the time it takes to start up and go through the encryption verification
process on an end-user's system.



Minimum Jaguar CD Track Size
----------------------------
When creating a Jaguar CD master, be aware that there is a minimum track
size of one megabyte imposed by the final encryption and re-mastering
process done by Atari.  In most cases, this will not be a problem, but
if you are very close to filling the disc completely, this may have an
impact.  Remember to always use a minimum of one megabyte per track when
calculating disc usage.  Also remember that Atari will need space for a
track containing encryption information and at least one short audio
track.



CD BIOS Notes
-------------
The CD BIOS documentation says the CD_read function returns an error
code in the err_flag variable.  This is not correct.  You do not get an
error code until you've called the CD_ptr function.  Also, the register
usage shown is not correct.  The CD_read function uses registers A0, A2,
and D1.

When an error value appears in register A1 after a CD_ptr call, you
should check that the address in A0 is equal to or greater than the
buffer start address given in the last CD_read.  If not, a CD_ack should
be issued prior to any other CD BIOS call.  Also note also that the
CD_ptr function sets the high bit of register A0 when a seek error
occurs.  This is not mentioned in the documentation.

The CD_mode function will return an error condition in err_flag.  CD
BIOS versions 4.04 and below, however, always mistakenly report an error
condition.  This has been corrected for future releases of the BIOS.



Christmas is coming...
----------------------
Developers and publishers should keep in mind that all cartridge-based
products must be fully-tested and released into production by October 5,
and CD-based products by October 31, in order to insure that your
product is shipping in time for the Thanksgiving sales weekend, the
beginning of the Christmas selling season.  Remember to allow at least 4
weeks for final testing.



Jaguar Tool Updates
-------------------
The Jaguar Developers Kit tools and related files listed below have been
updated in the last month.  You can download the latest versions from
the Atari Software Development BBS or from the Jaguar Developer library
in the Atari Gaming forum on Compuserve.

Jaguar CDROM Files — August 11, 1995.  This features some changes to the
included CD-ROM sample reader program, and changes to the CD Boot
Emulator.  Download CDROM.ZIP

Jaguar System Include Files — August 8, 1995.  See the article in this
issue for information.  Download SOURCE.ZIP

Jaguar Artwork Viewer — August 4, 1995.  This new version adds the
ability to control your horizontal resolution, and has improved
communications reliability.  Download ARTWORK.ZIP

Flash ROM Utility — July 27, 1995.  You can now hit Control-C to abort a
download and return to the DOS prompt.  Download UTILPC.ZIP.

Jaguar Graphics Tool — July 24, 1995.  Several minor bugs reported by
Jaguar Developers have been fixed.  Download ARTWORK.ZIP.




Dev Kit Roadmap
---------------
The tools, sample source code, libraries, and other components of the
Jaguar Developers Kit are updated frequently.  To keep track of what's
new, see the file ROADMAP.TXT that is posted online on the Atari
Software Development BBS and in the Jaguar Developer library in the
Atari Gaming forum on Compuserve.  This file is updated and reposted
whenever any of the standard distribution archives from the Jaguar
Developer's kit is updated.



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