Qix Emulator v0.1 by Ed. Mueller (Ed.Mueller@itg.ti.com)

This is the first version of an emulator to run the old Taito arcade
game Qix.  The emulator is not fully functional and has several problems
which are described below.

You will need to procure the original game ROMs from another source;
I cannot help you with that.  Put all the ROM files in the same
directory as the program.

Qix is a very finiky game with regard to the frequency of interrupts.
You can change how often interrupts occur by using the command line
parameter "-f".  The default value is 3000.  On a fast machine (Pentium
class), use larger values (e.g., 8000).  The larger the number the less
frequent interrupts occur.  You can tell if interrupts are running at
the proper rate if the game demo runs successfully to completion.

You can set the game's parameters by changing values on the setup screens.
For now, I regret that you must do some funky keystrokes to get through
these screens as follows:

Press F1 to go to the next screen.  After pressing F1, press F5 2-3 times
until the screen clears.  Then, press Shift-F1.

Press F2 to go to the next line.  Then, press the F5 and Shift-F1 keys as
described for F1.

Press F3 and F4 to change values.

Once you get to the "Game Over" screen the game will pause.  Press the
F6 key to continue.  After that, everything should be OK.

Press the 3 and 4 keys to insert coins.
Press the 1 or 2 keys for one or two players.
Use the arrow keys to move around.
Press and hold the Ctrl key for fast draw and the Alt key for slow draw.


Problems
--------

Other than the problems with the frequency of interrupts as described
above, the emulator has these additional problems:

1.  No sound.
2.  No joystick support.
3.  Speed is pretty slow on anything less than a Pentium 133 class machine.
4.  The screen is updated and player controls read based of the PC clock,
    that is, 18.2 times/sec. so the frame rate never changes.
5.  Need to implement a VESA scan mode so the screen aspect ratio looks
    correct.

I will hopefully be able to correct these problems in future releases.


Acknowledgements
----------------

I'd like to thank those persons who have contributed to making this
project possible.  I'd like to extend special thanks to Keith Gerdes
(kgerdes@worldnet.att.net) whose genius helped me get through several
tough spots and helped set the colors properly.

I'd also like to thank Keith Wilkins (kwilkins@nectech.co.uk) for making
his Vectrex emulator (DVE) source available.  I used his 6809 emulation
code as the basis for this project (Qix uses two 6809s - one for data/
sound and one for video).

And of course, special thanks to Nicola Salmoria (MC6489@mclink.it) for
his wonderful MAME.