

                        ******* MasterGear *******
             The Portable Game Gear & Master System Emulator
                             version 1.1

                         by Marat Fayzullin
                      
	             Acorn Port by David McEwen 
	             Port Version : 1.1 (31/8/98)
	             

Introduction
------------

This is a port of Marat's MasterGear emulator. This has improved emulation over the
old version and compatibility seems much higher.

Yeah I know we have Miracle, but atm it ain't perfect and it doesn't support Game
Gear games... also Marat is a brilliant coder and the more people that get to see 
the fruits of his labour the better. 


Note for users of old machines
------------------------------

The best way of using it is to increase the Uperiod and decrease the Vperiod & Hperiod 
in the options window. Please note that for older machines A5000... the screen mode 
will always be 320 by 256. 
The reasons for this are speed and guaranteeing the user has the right mode.
I am not saying this will be fast on old machines that would need a radical recoding
of the internal CPU emulation which I am not ready to do - I don't have that much 
time!!!


How do I use it ?
-----------------

Easy - just download a game from the internet there are various good sites around 
and few companies actually care what happens with these roms since they are in 
many cases over 10 years old and noone is really going to buy them in this day 
and age. One of the best sites is Daves Arcade Classics, great for MAME roms as well.

Once you have some ROMS you can run them by setting the filetype to SegaMS or SegaGG and 
double clicking or dragging the game to the MGear icon. This loads the ROM. 
To start the actual emulation click Select on the icon and away you go. 

It is fairly intuitive to use... 

The keys during emulation are :


  Cursor keys control movement

  [CTRL]  - FIRE-A button
  [ALT]   - FIRE-B button
  [RETURN]- START button (only in GameGear mode)
  [SPACE] - PAUSE button (only in MasterSystem mode)   
  [TAB]   - RESET button (only in MasterSystem mode) 
  [ESC]   - Pause emulation (also: [F11]) (Click on icon to restart)
  [F5]    - Reset Emulation (can also be accessed via menu)

  
  In the near future they will be conigurable in the front end.  
  
The frontend allows you to alter various variables that will affect the
speed of the game - the Uperiod and Vperiod values. Uperiod is sort of equivalent 
to a frame skip, and Vperiod is the clock cycles per screen refresh. The lower the
value the more probs that may occur... some games require higher values to work well.
Hperiod is the number of clock cycles per scanline.

There are several resolution choices available. The first 4 are simple resolutions
no scaling is implemented. There is a full screen mode. The MDF file included provides 
definitions for the modes on an AKF60 monitor. These are the same modes as used by Gareth
Moore in his port.

The Delay option determines whether VRAM reads are delayed or not. This may make games
work better or worse...

The pause function mean that when you press Escape or F12 the emulation isn't killed
instead it is paused so that it can be continued from that point by clicking on the
icon. If you wish to reset the emulation either press F5 while in the emulator or
click on Reset in the menu.

Also sound can be toggled on and off - the sound is not perfect, there is a definite
problem with tones, noises are fine in the main.

For those with StrongARMs there is a frame locking option, which forces update to 
the set number of FPS regardless of the refresh rate of the mode it is running in!!
 
A future release should hopefully be running in a window... I will try and optimise as
much of the code as I can!! This may also mean that it becomes more playable on older
machines, but please do not expect miracles. 

No SRAM support in this release, next version will. I have a few things on the go atm, so
give me a chance ;-)

Sound is preliminary... and thus there is no Noise sound. It isn't perfect, due to some 
wrapping of the pitch values that is occuring.
 
 
*FAQ*
----- 

Why are my Roms images not working ?
-------------------

Try downloading them again. If there is still no joy. Send the image to 
Marat and see if he can find a reason. 

Where's the sound ?
-------------------

It's here!! Not brilliant, but at least it can be turned off.


Do I need a special screen mode ?
---------------------------------

Nope the emulator runs happily in a 320 by 256 mode as the screen fits nicely. 
The full screen modes require  specially defined modes... a Mode Definition File 
is included. 

Will you get it to run in the desktop ?
---------------------------------------

This will be coming shortly...


Will you be porting any other emulators ?
-----------------------------------------

Current emulator tally :

!ColEm
!fMsx
!ARCNes
!Stella
!Atari800
!MGear

Aren't 6 enough ?????

Alright if you insist... keep an eye on the Acorn Emulation Pages...	
	http://www.cybervillage.co.uk/acorn/emulation


Copyright and Disclaimer
------------------------

This emulator is copyright Marat Fayzullin 1994-6, and the Acorn-specific
components are copyright David McEwen 1998. You may not attempt to pass off
any part of this work as your own, although you may distribute it freely as
long as you supply the complete archive (that is, all the files supplied to
you).

This software is supplied "as is". I make no claims about the reliability or
suitability for any purpose of this emulator, and any use of it is undertaken
at your own risk. No responsibility is taken for any failure of the software,
or for any loss or damage caused directly or indirectly by the software.

Whilst I will endeavour to help you if you have problems with this emulator,
no such support is guaranteed.

In the above "This emulator" refers to everything supplied within this
archive, which is specifically the !MGear application and all the files
contained within it, and also the documentation files (including the one you
are reading now).



COMMENTS
--------

Any comments about the emulator as such should go to Marat Fayzullin : 
email : fms@komkon.org
Website : http://www.komkon.org/fms

Any comments about the Acorn specific parts and please no inane emails giving 
me ways of making money etc... just useful constructive stuff please
email : david@lizjay.demon.co.uk (Home)
	davidm@argonaut.com (Work)
Website : http://www.lizjay.demon.co.uk/david

Thanks
------

Gareth Moore for providing help on returning to the desktop mode, and allowing
me to work on all future versions of the Acorn port of MasterGear. 
Peter Teichman for help with DataVox...
Marat Fayzullin for writing this emulator and providing help!!