[sdiy] Space Invaders running on 3E board!

[Paul Schreiber]

I just figured out the "da Vinci Code" in getting this to work on the 3E demo 
board.

a) go to your xilinx\spartan3e directory on your drive. Make a new sub-directory 
called invaders.
b) go to www.synthtech.com/fpga and download the 2 files into that 
sub-directory.

One file is the BIT file that tells the Xilinx FPGA how to interconnect all the 
logic gates. The other file is a batch file that will call the iMPACT serial 
downloader, look for the board, and program the FPGA.

c) connect the 3E demo board by attaching the USB cable. Also, attach your VGA 
monitor to the VGA connector, and the keyboard to the PS/2 connector. Turn power 
on. The board will run whatever is in FLASH (most likely the program that 
shipped with it).

d) Run the invaders.bat file. This will shell out to MS-DOS, the BIT file should 
download to the board. The whole process is 10 seconds or so.

e) The LCD will 'freeze' where it was (Invaders does not use the display). 
BUT....you should see on the VGA screen *sideways* the game running! Note: 
chances are, you will have to manually adjust the horizontal size controls on 
your monitor (on my LCD, I had to 'squish' the image about 20%). The <> arrows 
move, the spacebar fires. To start, hit the C key (for coin) and press 1 or 2 
for # of players.

f) yes, there is a way to get audio out but that's a later chore.

This is running a full Intel 8080 CPU *and* uses the original 2K EPROM files 
from the machine. The game uses about 33% of the available gates in the 3E 
device. Enjoy!

Let me know if it works for you or not. Also impressive (to us old farts): the 
VHDL synthesis, place & routing took about 4min on my Dell PC.

Paul S.