Pac-Man on TangNano

This is the main README for original implementation on TangNano9k. For TangNano20k port, check also README_20k.

Pac-Man on TangNano9k

A Pac-Man Arcade implementation for the TangNano9K using HDMI for video and audio output. See it in action in the Youtube Video. The latest version supports the use of a USB Joystick as demonstrated in this video.

Why another Pac-Man in HDL?

There are many Pac-Man implementations in HDL, especially the great version by MikeJ. I wanted to gain some experiences with the GoWin FPGAs and wanted to make use of the HDMI output of the TangNano9K. So I wrote another Pac-Man using HDMI.

Most existing versions recreate the original video and in a way that outputs an upright 60hz signal with NTSC timing expecting the screen to be mounted in portrait mode as it was in the original Arcade machine. Such a signal can be converted to HDMI in landscape format. But that needs a seperate frame buffer.

I wanted to implement the video to directly output a signal compatible with modern screens. So the video logic implemented here does not work like the original arcade machine. Instead it replaces the video logic by something that outputs a double scanned signal with 576 lines (576p@60hz).

By default the video is 1024x576p to nicely fit a 16:9 screen. The game area is displayed centered with a dark blue border left and right. The video can be configured to output a 4:3 video with a resolution of 768x576p instead by commenting ``define WIDE` in line 4 of src/top.sv.

ROMs

Since this project implements the hardware of the Pac-Man Arcade machine it needs the original ROM files to run. These can be obtained from the Pac-Man (Midway) romset.

The ROMs need to be converted into HDL source files compatible with the GoWin toolchain. This can either be done manually using the GoWin IDE or via the Python conversion tool and a shell script.

ROM file	Contents	Verilog file	Module	Depth	Width
pacman.6e	CPU ROM #1	pacman_6e.v	pacman_6e	4096	8
pacman.6f	CPU ROM #2	pacman_6f.v	pacman_6f	4096	8
pacman.6h	CPU ROM #3	pacman_6h.v	pacman_6h	4096	8
pacman.6j	CPU ROM #4	pacman_6j.v	pacman_6j	4096	8
pacman.5e	tile graphics	pacman_5e.v	pacman_5e	4096	8
pacman.5f	sprite graphics	pacman_5f.v	pacman_5f	4096	8
82s123.7f	color palette	82s123_7f.v	prom_82s123_7f	32	8
82s126.4a	colormap	82s126_4a.v	prom_82s126_4a	256	4
82s126.1m	audio wavetable	82s126_1m.v	prom_82s126_1m	256	4
82s126.3m	audio wavetable	82s126_3m.v	prom_82s126_3m	256	4

The easiest way to convert these files is to place the ten ROM files in the src/roms directory and then run the shell script.

Usage

Convert the ROMs as described above.

Open the project file pacman.gprj from the corresponding board folder in the GoWin IDE run the synthesis, place & route and download the resulting bitstream onto the TangNano.

Buttons

Once the game runs it can be controlled with six buttons connected to the TangNano9K as depicted below:

The pins used are:

Function	Pin Name	Pin No
Up	IOB8A	25
Down	IOB8B	26
Left	IOB11A	27
Right	IOB11B	28
Coin	IOB13A	29
Start	IOB13B	30

USB joystick

You can also use a USB joystick.