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Jaguar Developer Weekly           July 28, 1995                  Vol.1, No.6
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New BBS Number
--------------
The new phone line for the Atari Software Development BBS will be active as
of Monday, July 31.  The new number will be (408) 541-9164.  The old phone
number for the BBS will no longer be active, so please make a note of the new
number.  The new line won't 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.



Undefined Symbols In Madmac Expressions
---------------------------------------
There are certain limitations on using undefined symbol names in expressions
that do not generate warnings or error messages at assembly time, and which
aren't clearly defined in older versions of the Madmac documentation.  The
following text is a recent addition to the Expressions section:

Externally defined symbol names cannot be used in mathematical expressions.
If you do this, you will get unpredictable results.  This is true even if the
symbol is declared as being external using the .GLOBL or .EXTERN directives.
For example, if external_symbol is not defined within the same file, then
example 1 below will work, but examples 2 and 3 will not:

1) move.l	#external_symbol,a0
2) move.l	#external_symbol-2000,a0
3) move.l	#external_symbol-local_symbol,a0

The reason this does not work is that these types of expressions would
require a variety of different operations to be performed at link time in
order for them to be properly resolved, and the relocation method used by
MADMAC and the ALN linker does not currently support this.



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.



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.



Jaguar CD Track Format
-----------------------
A quick reminder to developers working on CD titles: it's very important to
follow the correct format for a Jaguar CD-ROM track and include the proper
track header and tailer information.  Failure to do so will prevent you from
creating a bootable CD.

The proper format for a Jaguar CD-ROM track is described in the Jaguar
Developer documentation in the section entitled The Jaguar CD-ROM:
Programming, Procedures, and Guidelines in the Jaguar CD-ROM chapter.  Here
are some of the highlights:

Note: The text below contains some clarifications to last week's article:

The start of each data track (i.e.  session #1 and above) must contain a
specific Atari data header, and the end of each track must contain a
corresponding data tailer.  No data may precede a track header or follow a
track tailer.

The header must consist of 16 repetitions of the string "ATRI" (64 bytes
total) followed by the 32-byte string:

"ATARI APPROVED DATA HEADER ATRIx"

where the "x" at the end is ASCII 32 + the number of the track (starting from
0, relative to the boot track at the beginning of session 1).  For example,
the boot track would have an ASCII 32, the following track would have an
ASCII 33, etc.

The tailer must be long aligned (i.e.  your data must be a multiple of 4
bytes in length) and consist of the 32-byte string:

"ATARI APPROVED DATA TAILER ATRIx"

The "x" should be the same value as in the track header.  This is followed by
16 repetitions of the string "ATRI" (64 bytes total).

The boot track of a Jaguar CD-ROM has two Motorola-format long words
immediately following the track header.  The first specifies the target
address of your boot code, which must be between $4000 and $FAFFF.  The
second specifies the length of your boot code, which should be no longer than
64K.  The boot track may be longer than this, but only 64K will be loaded
automatically at boot time by the system.



CD Error Handling
-----------------
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.



Memory Track NV-RAM Cartridge
-----------------------------
Memory Track is an Non Volatile RAM (NV-RAM) cartridge used by Jaguar CD
titles to save game high scores, user options, and save-game information.  It
is accessed via a set of BIOS routines which are organized and used much like
a disk file system on a computer.

The NV-RAM Simulator uses the Alpine board to simulate the Jaguar NV-RAM
cartridge during the development process.  This is available in the
JAGLIB.ZIP archive online.

The NV-RAM BIOS allocates cartridge memory in 512 byte blocks.  To get the
best performance, your program should read or write NV-RAM in multiples of
512 bytes at once.  Doing reads or writes with smaller amounts of data will
work, but is many times slower than reading or writing the same amount of
data in one step.  The difference is easily noticable to people using your
program.



Important Note about Adobe Premiere 4.0
---------------------------------------
Several in-house and third party developers have had difficulty in creating
Cinepak movies for Jaguar titles using Adobe Premiere 4.0.  These errors are
consistent with internal rounding errors that cause video frames to
occasionally be added or skipped.  In addition, these errors have induced
'clicking' in audio samples that are resampled by Premiere.

Adobe Tech Support has acknowledged these problems and is planning to correct
them in some future update.  Until then, Adobe AfterEffects (formerly CoSa)
is not known to suffer from these problems.  To correct Audio resampling
problems, we have used Macromind SoundEdit 16 with success as it has the
ability to edit the audio stream of a Quicktime movie atomically, without
necessitating the recompression of video on resaving the file.



Jaguar Tool Updates
-------------------
The Jaguar Developers Kit tools and related files listed below have been
updated in the 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.

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.

Jaguar NVRAM Simulator — July 21, 1995.  The NVRAM simulator uses the Alpine
board to emulate the Jaguar Memory Track cartridge, an add-on for the Jaguar
CD that allows CD game titles to save their user options, high score lists,
saved-games, and other information.  The archive has been updated with
additional documentation.  Download JAGLIB.ZIP for the complete package.

Jaguar Cinepak Utility — July 7, 1995.  A couple of small cosmetic glitches
have been fixed.  Also the program now gives an error if the QuickTime movie
you are trying to convert does not use Cinepak for video compression.
Download JAGMAC.SEA using MacBinary on the Macintosh, or download to your PC
and use a MacBinary-intelligent utility to transfer the file to your
Macintosh.  Once you get the file to the Mac, JAGMAC.SEA is a self-extracting
archive.



Developer Kit Archive 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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---------------------------------
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