Contents | < Browse | Browse >

%% EGS FAQ                                               By Brian Wright %%
%%                                              ( %%

Welcome to the EGS (Enhanced Graphics System) frequently asked questions
document.  This document will be maintained as frequently as is necessary
when new questions arise.  Within this document you will find questions
which are generally and frequently asked by people new to the EGS software
system.  Hopefully some of these questions and answers will help you.  If
you find that your questions are not answered by this document, feel free
to email to the maintainer of this document (the name is located at the
bottom of this document).

This document will be primarily used for EGS related questions, but
graphic board specific questions as related to EGS may also apply and
therefore be included. 


Question:  What exactly is EGS?


EGS is the Enhanced Graphics System developed by Viona Development.  It is
a retargetable graphics system (via a set of libraries) for use primarily
with specific Amiga graphic boards.  EGS can also be run on the native
Amiga graphics system (ECS, AA (aka AGA), and possibly OCS with enough
memory).  EGS is mainly licensed by specific graphics board manufacturers
for inclusion with their graphics boards (for example, Spectrum and
Piccolo both use EGS).  EGS also includes software tools to adjust
resolution, screen colors, pointers and screenmodes. 

EGS, when run in the native Amiga modes (OCS, ECS or AA), is limited to
the resolutions and depths of that system.  EGS does not extend or in any
way alter your graphics capabilities.  It makes use of whatever graphics
system and capabilities you currently have. 


Question: Why do I need EGS?


EGS is an alternative to Intuition in that it supports depths up to 24 bit
(16.7 million colors).  Intuition is only capable of up to 8 bit depths
(256 colors...even in 3.x versions).  EGS provides you with a way to deal
with depths above 8 bit in as fluid a way as Intuition.  In some ways, EGS
is superior to Intuition.

EGS also gives non-AA equipped Amigas a way to deal with higher screen
depths and higher resolutions (provided you have a a display device
capable of displaying them).  In fact, since EGS gives you a way to deal
with greater depths and resolutions, certain display board's capabilities
will surpass that of AA. 


Question:  How much hard disk space does EGS require?


EGS requires between 4 and 5 megs (at minimum) HD space.  More than 
that if you intend on storing 24 bit images.


Question:  How much RAM is required to run EGS?


EGS requires at least 2 megs of system RAM (per the Spectrum manual). 
However, the more you have, the better EGS will operate.  If you have 5
megs of RAM, you will be able to run most of the tasks comfortably at 8
bit.  You might find, however, that at 24 bit you run out of RAM quickly.

If you never run any EGS programs and operate strictly off the emulation, 
you'll almost never run out of RAM.  In fact, with a display board, you
free up CHIP ram because you are using the external board for the screen


Question:  Why do I need so much RAM?


EGS swaps whatever is not currently in the display buffer on the board
into your system RAM.  For example, if you have a 768x482 24 bit screen
open and you push that screen to the back, the data on the board will
be swapped out into your system RAM.  If another EGS screen is popped to
the front, that RAM is swapped back onto the board.  Therefore, you will
need enough system RAM to swap all non-displayed EGS screens into.


Question:  Will virtual memory systems work with EGS?


Yes, for the most part.  Almost every EGS tool that came with the Spectrum
works very well with Gigamem.  The first program that you run will
allocate the memory for the EGS Screen that opens the screen first.  That
first program run will also be the one that swaps in and out when you move
the screen from front to back.  Until you close all windows on the screen,
the EGS screen will remain active and the VM will remain reserved (see
question #5). 

Any VM system you install will greatly increase the usability of EGS by
giving your system much needed RAM.  Remember though, VM is slower and
requires HD space with which to swap into.  The VM system will also
require an MMU equipped Amiga which includes the A3000, A4000/040 and
any full 020/030 accelerated Amigas with an MMU.


Question:  How does the EGS screen system work?


The EGS screen system opens what's called the EGS Default Screen.  This
screen is much like a 2.x/3.x default screen where you can shanghai
programs.  The only difference is that this EGS screen is strictly for EGS
programs.  All of the EGS tools included appear on this screen.  This
doesn't mean that all EGS programs require this default screen for use. 
In fact, any EGS program can either choose to use the EGS Default Screen
or open their own custom EGS screen for any specific legal size or depth. 

EGS screens are currently not draggable.  This includes the Workbench 
emulation.  In other words, any screen which is either native EGS or has 
been promoted up to an EGS resolution will not be draggable.  This could 
change in the future.


Question:  How do the front to back gadgets function?


The front/back gadgets work a little differently with EGS installed.  EGS 
screens are kept as a seperate list of screens from the list of Intuition 
screens.  Therefore, because Intuition knows nothing of EGS, it is unable 
to flip to any other screens than Intuition screens.  Because EGS is 
aware of Intuition, EGS screens can flip to the next available whether 
Intuition or not.

For example, you have two screens open: an EGS screen and the Workbench 
screen.  If you hit the front/back gadget on the Workbench, nothing 
happens.  This is due to Workbench and Intuition not knowing about EGS.  
If, however, you were on the EGS screen and hit the front/back gadget, it 
would flip to the next screen whether EGS or not.  It can do this because 
it is aware of both the EGS list of screens and Intuition's list.


Question:  How do you set the resolutions for EGS?


EGS adds screen resolutions to the system ScreenMode database.  Any 
program that supports this database can access these new resolutions and 
take advantage of EGS.  Both Intuition and EGS use this ScreenMode 
database with which to select an appropriate screen.  Promotion tools 
also use this database so that you may promote one screentype to another 

To create entries for the ScreenMode database, refer to the DisplayAdjust 
program for more details.


Question:  What is screen promotion?


Screen promotion is a method by which you can specify any specific
application which opens a certain set resolution to open in any other
resolution.  Some various tools which support this are Promotor,
ScreenModeChanger and Pprefs. 

NOTE:  Keep in mind that some applications do not like being promoted or,
because of the way they handle their graphics, can't be promoted. 


Question:  Does EGS have a Workbench emulator?


Yes.  Since EGS patches the ScreenMode database, you can use the system
Screenmode pref to put your Workbench into any resolution in the database. 


Question:  What's the difference between EGS and the Workbench Emulation?


EGS is an independant software display system capable of its own custom
screens with windows on those screens.  The Workbench emulation uses
Intuition and the ScreenMode database to put Workbench as well as other
Intuition screens onto your display board.  Each system is seperate from
one another.  EGS applications can't be displayed on Intuition.  Intuition
applications can't be displayed on EGS (not yet anyway :).


Question:  Is EGS easy to install?


Yes, it is.  Just make sure you have enough space to install it.  Your 
EGS distribution should have come with a Commodore installer script to 
make the installation process simple.


Question:  Will my A3000/A4000 equipped with an older revision buster
           work with any of the Zorro III boards (Spectrum or Piccolo)?


Yes.  You can run your graphics card in Zorro III mode without many, if any
problems.  It is not *required* that you buy a new buster for your machine.
See question 10.2.


Question:  What is the revision number of the buster I will need if I 
           decide to change it?


The revision buster you will need is revision K or revision 11 (same thing).


Question:  Will I see any speed improvements by installing the new
           buster chip?


At this time, it is unknown if you will experience any speed improvements
by changing this chip.  You will, however, clear up any potential DMA
problems by replacing it.

NOTE:  If you decide to replace this chip, it is recommened that you order
the chip puller from your dealer at the time you order the chip.  You 
may also let your local dealer change it if you do not feel comfortable
enough doing it yourself.


Question:  What is the current version of the EGS system?


The current version of EGS is version 6.0 of the libraries.  Some systems
may still be shipped with version 5.0 of the libraries.  If you find you
have version 5.0, contact your dealer for an update.


Question:  How will EGS library and software updates be handled?
           Who will I get it from?


At this moment in time, updates to the libraries and software will be
handled through your board's manufacturer and not through Viona.  Contact
technical support from your board manufacturer/distributor to find out how
they intend on distributing library and software updates. 


Question:  With my Workbench running an EGS resolution, some programs have
           stopped functioning?  What's happening?


Poor programming. ;) No seriously.. Some programs try and adopt
Workbench's screen size and depth.  If you are running 800x600x256, the
errant program may not know how to create such a screen and fail.  This
happens most likely because the program knows nothing of the Screenmode
database and therefore can't request the appropriate Screenmode with which
to open the screen.  More than likely it is a 1.3ish program doing this.
2.0 and especially 3.x aware programs seem to have fewer problems in this

The solution is to temporarily move your Workbench screen back to a
non-EGS screenmode using standard ECS/OCS.  The program should run fine
with this setup.  After you run the program, you should be able to put the
Workbench back into the EGS resolution and leave the other program
running.  It is a hassle, but it should work.  Otherwise, call or write
the company and ask them to fix the program. 

If this solution does not work, the program may be failing due to other
reasons.  At this point, you should consult either someone from 
Viona, someone from where you bought your graphics board, or email the 
EGS list on Internet.


This FAQ will be updated as questions are asked.  I have added what I
think are some of the most common questions.  There are, I am sure, many
more questions which still need to be asked and included.  By all means,
if you have a question, ask it.  I'll try to get a response to it as
quickly as possible.  Whenever I see a FAQ type question and a good
response, I will add it to the FAQ.  If any of the current questions need 
revision or expansion, please let me know.

I am hoping in the future to put this document into other formats such as 
TeXInfo for porting over to such readers as ASCII and AmigaGuide to name 
a few.  At first, however, I plan to work on it in ASCII just to get it 

Please submit any questions to Brian Wright <>.  
Thanks much.