Scramble, released in 1981, was the worlds first multi level shoot-em-up. Frogger, also released in ’81, is probably one of the most well-known arcade games today, with numerous conversions to other platforms.
Here is a VHDL model of the original hardware so the games can be re-created in modern FPGAs.
The games uses two Z80 processors. I designed a quad Z80 core designed for Xevious which time division multiplexes the majority of the core and is only a little larger than a single Z80. However for simplicity here two Z80s are instantiated, and it still fits easily into the Spartan3 500E on the eval board, the whole design taking about 68%.
The design also includes two AY-3-8910 sounds chips and two 8255 PIA chips. I have attempted to digitally model the filters on the audio board as well.
If anybody has a real board running can they let me know if the stars and audio are correct – we aim for 100% accuracy here….
Currently supported games include:
* Scramble (Stern)
* Armoured Car
* Super Cobra
Experimental INI’s are also provided for:
* The End (Konami)
* The End (Stern)
Attach joystick to port 1. A second joystick is currently not supported.
### Virtual keyboard
The joystick in port 1 is emulated in parallel using the virtual keyboard:
* Cursor up, down, left, right
* enter -> Fire
* space -> Fire 2 (bomb)
* key 5 -> Coin
* key 1 -> Start 1 Player
* key 2 -> Start 2 Player
## Video output
R1 and V4 both output 640×480 progressive at ~60 Hz on DVI (-A and -D) and HDMI, respectively.
* Original FPGA conversion by Mike Johnson
* T80 core by Daniel Wallner, Mike Johnson
Please read the “Readme.md” file for documentation.
This core supports multiple games, INI files for each game and ROM set names are included.
IMPORTANT NOTE :
NO ORIGINAL ROM CONTENTS ARE IN THIS DISTRIBUTION. YOU WILL NEED THE ORIGINAL/ALTERNATIVE ROM FILES TO RUN THE SCRAMBLE GAME