|
|
This Technical Note discusses the MacinTalk software product.
[Feb 01 1990]
|
Introduction
For the introduction of the Macintosh computer, it was decided (by the powers
formerly in charge) that such a computer would need something very special to
make it a unique event. To aid in this concept, a third-party company was
contracted to write a speech synthesizer which would allow the Macintosh
computer to introduce itself. The contract was signed, and the work begun.
The outcome of this work was MacinTalk. MacinTalk is a file that can be placed
into the System Folder of an ordinary Macintosh computer and allow text to be
transformed into speech for the introduction in 1984. It was felt to be an
interesting piece of software, so Apple made it available to developers.
Interfaces to MacinTalk were published and Apple Software Licensing allowed it
to be included with developers' products.
The original project was to get a speech driver for the Macintosh, but it did
not include obtaining the source code to this driver. Apple only has exactly
what it gives to developers: a file to be copied into the System Folder, and
this file cannot be changed since Apple does not have the source code.
MacinTalk works by using a VBL task to write data directly to the sound
hardware of the Macintosh Plus and SE logic boards--a method which Apple does
not support. It has only been through the efforts of the Sound Manager that
software that writes directly to this sound hardware continues to work.
MacinTalk continues to write to the hardware addresses of the Macintosh 128K
logic board, but the Sound Manager and the Apple Sound Chip work together to
allow programs like MacinTalk to continue working on newer machines. The Sound
Manager and the Apple Sound Chip were introduced with the Macintosh II.
The Sound Manager watches the hardware addresses that used to be present on the
Macintosh. When the Sound Manager detects activity at one of these addresses,
it goes into a "compatibility" mode. In this mode, it routes the data to the
real sound hardware, but while this is happening, proper Sound Manager code
cannot run--even the Sound Manager's _SysBeep does not work when
MacinTalk is in use. Furthermore, the compatibility mode cannot be turned off
until the application requiring it calls _ExitToShell. Even an
application that uses sound properly, with correct code, does not work if
another application opens the MacinTalk driver. There are no solutions
to this incompatibility. MultiFinder and System 7.0 allow more than one
application to run concurrently, so it is possible for an older application
which uses MacinTalk to limit the features and abilities of a new and improved
application.Around the time of the Macintosh II introduction, Apple made a
single hack to MacinTalk to remove self-modifying code which caused a problem
for 68020-based machines. This modified version, known as 1.31, was available
from APDA with the warning that "Apple does not provide any support for
MacinTalk. Not even to Apple Certified Developers." While this warning is
still true and APDA continues to sell MacinTalk 1.31 as a "Class 3" product,
the official Apple position about it is: "Apple Computer, Inc. does not
recommend that you use Class 3 products for developing commercial
software--they are intended for your personal enjoyment only."
In other words, if you find MacinTalk interesting and entertaining--go ahead
and purchase it. Write some code and enjoy. However, be warned that MacinTalk
should not be included as part of any commercial product. Apple
Computer, Inc. provides no support for MacinTalk other than what is purchased
with the package itself, and there will be no support in the future. Apple is
committed to providing the developer community with an array of speech
technologies integrated with the Sound Manager. In preparation for certain
system software changes, such as System 7.0, Apple does not recommend the
continued use of the existing MacinTalk package.
Back to top
The Surgeon General Warning
The development of MacinTalk ended with the introduction of the Macintosh in
1984. Nothing more will be done to this product. It is a compatibility risk
to use MacinTalk. It causes the Sound Manager to fail. It will not
work with the new Sound Manager planned for System 7.0. This system revision
will also introduce the new feature of virtual memory; it is not expected that
MacinTalk will work while the user has Virtual Memory running. It may not work
at all with future versions of the Macintosh hardware. Continued use of
MacinTalk is a major compatibility risk. Do not operate heavy machinery while
under the influence of this product.
Back to top References
Inside Macintosh, Volume V, Compatibility Guidelines
The Sound Manager, Interim Chapter (DTS)
M.TB.ClicklessSound
Back to top Downloadables
|
|
Acrobat version of this Note (K).
|
Download
|
| 
