Chris Covell's Creations - Mark II

Here are the things that I worked on while living in Japan (2002 - present.)  You can see my older creations back at my other page.

PC-Engine / TG-16 Software

--> PCE ASM coding tutorial page! <--

Hu-Boy : a Game Boy emulator for the SGX / PC-Engine CD!

Yes, it's kind of a crazy idea trying to emulate another game system on the PCE, especially if its CPU architecture is totally different as in this case. But, read on in the dedicated page for Hu-Boy, and give it a whirl!

Binary Star

You can also call this "the 30-year anniversary MSX SCC music disk for the PC-Engine", whichever rolls off the tongue better.  It's a music disk, no other frills or features, but I hope it adds some enjoyment to your day, with PCE emulation of some classic Konami SCC tunes.

HERE is a detailed technical description of the programming behind Binary Star

 YouTube Link!

Also, you can vote for it on

PCEmon is a Serial Monitor / Debugger for the PC-Engine / Turbografx-16.  It has many features for debugging and downloading/uploading data between your PC and the PCE/TG.  Read more in the link to the left!

HuZERO is a futuristic racing game for the PC-Engine, which I made as a tribute to a great Mode-7 racer on the Super Famicom.

This version is a "Summer Caravan" parody edition which, if you're familiar with Hudson's Caravans, gives you 2 minutes to attain a high score. And not die.

  1. 76037 Morden
  2. 75569 Fragmare
  3. 75420 Necromancer
  4. 73593 rcantor77
  5. 73158 Roflmao (Dan)
  6. 72374 Cabbage
  7. 71636 Corrado Tomaselli
  8. 70268 Debvgger_
  9. 69715 Joe Redifer
  10. 65588 Abraxas86

I'm quite happy that HuZERO was voted 4th in the "Game of the Year 2014" awards on the demoscene site!!

Hey! If you send me a screenshot of your best score, I'll put it on a high score list! :-D

Tongueman's Logic is a PC-Engine/Turbografx-16 game that I released in October 2007.

Please check out the page I made for it HERE!

PCE Visual Music Player

This is a tool that plays PCE game music, and displays each channel's notes, volume, and waveform (instrument) visually.

Each channel's frequency/note/volume is printed in a different colour, from red to purple. The volume of each channel is in a dimmer shade of the same colour.  Everything scrolls upwards, like a ticker tape/seismograph/player piano, as the song is playing.

You can set each of the 6 channels on/off, zoom out to view more of the note range, change the playback speed, and turn on/off the "Autoplay" option, which goes to the next song when its time is up.

PCMgine Waveform Tool - a quick release to support a YouTube video series that I'm working on.

OLD IS BEAUTIFUL is a slideshow (with some cool sampled/tracked music!) that shows more colours onscreen than you would normally think the PCE is capable of.  (For example, it shows 15 shades of red rather than the PCE's internal limit of 7 shades...)

This demo needs to be run on an NTSC Turbografx/PCE through composite video.

ROM link
Source code link

YouTube link!

Courage is a little "Diskmag" or ROM-based magazine with graphics and music that you can read/play around with on a real Turbografx / PC-Engine system.

The archive includes a ROM for emulators/flashcarts as well as an ISO for burning to a CD!

You can read one excerpt *here*!

R-Type PCE/TG-16 to SuperGrafx Hack (Unfinished) *new*

This is an IPS patch that makes R-Type (US ROM) take advantage of the SuperGrafx hardware for reduced sprite flicker.  It is unfinished, but now includes source code; read the README for more details.

PCE SID Player Source Code

PCE SID Player

I've released the source code and a test demo for the SID engine that I used in my Courage diskmag.  Peruse the source if you're an ASM programmer!


Downland Remake

Click on the image to the left to read more about it.

Fractal Engine 2

This is a Mandelbrot fractal generator for the PC-Engine. It's certainly not as fast as PC-based fractal programs, but remember that it's running on an 8-bit CPU. It's fun to experiment and play around with.

Includes a CUE/ISO file for burning to a CD!

Improvements over version 1.0

+ Twice as many colours in low-resolution mode!
+ Detects SuperGrafx hardware for even more colours / resolutions.
+ Julia Set now accessible!
+ Average of 1.7x speed increase.


This is a program for the PC-Engine that lets you view files saved in the backup RAM (BRAM), make backups of the BRAM files, and even edit the data inside BRAM files.

This program is useful for cheating in games, or even just for exploring the save files that your favourite PCE/Turbo games create.

Now includes a CUE/ISO file for burning to a CD!

Split-Resolution Demo

This demo splits up the screen into 3 regions, and shows different resolutions in each region! It looks great on a real PC-Engine system, even though many emulators fail to run it correctly. "Mednafen" runs it quite well.

Click on the images to the left to see what the Split-Res demo looks like on a real PC-Engine.

Click HERE to download the demo.

Now includes a CUE/ISO file for burning to a CD!

SuperGrafx Demo

This is my first (the first?) graphics demo for the NEC SuperGrafx system. I wanted to see what this baby could do, and the result is rather nice. I hope you'll agree with me.

This demo should be run only in a good emulator that supports the SGX hardware.

Now includes a CUE/ISO file for burning to a CD!

Screen Dimension Test (Newer Version)

Don't be scared by all the numbers, but this is a small tool for a real PC-Engine to adjust various screen settings to see what the maximum screen area that can be displayed on your PCE and TV is.

Now includes a CUE/ISO file for burning to a CD!

PC-Engine Pad Test

A simple ROM to test joypads.

CPU Timing Test *new!*

This is a tool for PC-Engine emulator or simulator authors to verify the timing of CPU instructions against real hardware.  Click on the link to the left for a pretty detailed description and test results.

"Hidden PCE Pics" Demo

This is just a small slideshow that displays some pictures that were hidden away in some PCE CD games.

Greyscale Mode Demo

This is a demo which displays over 100 shades of grey on the PCE, which usually can only show 8.

It only works on a real PCE system, and with some video problems at that. The greyscale mode on the PC-Engine can be called a hack, at best.

Still, smoothly-shaded greyscale pics DO look really nice on my TV. (^_^)v

512-Colour Test Demo

This is just a simple demo that displays all of the 512 available colours of the PC-Engine on a single screen!

"Bomberman" Raster Demos

This is a collection of 6 demos that display a still picture and warp it line-by-line, in the same way as Bomberman on the PC-Engine does at its title screen.

Check them out!

Wavy Graphics Demos

This is a collection of 6 demos that display a still picture and warp and skew the pic in a variety of ways. Some of them are psychedelic; some are relaxing.

Check them out!

High-Resolution Slideshow

This is a little demo for the PC-Engine/Turbografx-16 that uses the PCE's built-in (but little-used) 512x240 pixel resolution to show some neat pictures.

It'll change pics (4 of them) automatically, so just sit back and relax!
The demo was tested on a real PCE system, but if you can't use that, then you'll need to use an emulator that supports the hi-res mode (Magic Engine currently isn't one of them!). I would suggest YAME, or Hu-Go!

"256-Colour" Slideshow

This is a small demo that displays pictures that contain more than the usual 16 colours; in fact, the OutRun pic seen on the left contains 72!


Sega Master System/Game Gear Software


Game Gear Hicolor Demo

This is my first demo for the Game Gear. It's a small slideshow, and it displays up to 288 colours on-screen at once, something that I don't think has been done before on the GG. It'll look best (?) on a real Game Gear, of course. Download it and enjoy!


SMS 3-D Demo

This is my first demo for the Master System. It uses the 3-D glasses to display images in a slideshow, with a 3-dimensional effect!

SMS YM2413 FM Tool

This is a small tool that lets you experiment with the FM sounds out of the YM2413 sound source in the Japanese Mark III and Master System.  You can get some crazy sounds out of this sound chip.

As a demonstration, I made a YouTube video, recorded from a real SMS' audio.

This tool won 3rd place in the SMS Power Coding Competition 2015!

I recommend using Japanese paddle controllers, since you can adjust various level settings (like pitch) smoothly and naturally. However, a regular SMS joypad will work.

Source code is also included in the archive.

Game Translations / Hacks

Keith Courage (Turbografx-16) / Mashin Eiyuu Den Wataru (PC-Engine) NOVA Suit Hacks

These are .IPS patches for the beloved pair of TG/PCE games. The patch lets you choose how you want to play the overworld or underworld levels, either as the boy Keith, or permanently decked out in the NOVA Suit!

Ginga Denshou (FDS) English Translation

I've translated this okay-ish Shoot-em-up-Action-RPG-Shooter into English.  Read about it on its own page!

Head Buster English Translation

Head Buster is a turn-based strategy game for the Game Gear. And it's actually quite fun! Check out my translation effort by clicking on the pics to the left.

Famicom / NES Software

TapeDump: A poor-man's dumper for the NES/Famicom

This program can dump (copy) to your computer a large number of NES/Fami cartridges and FDS disks without the need for any extra interfacing hardware! Read more here.

FDS Disk Listing Program Version 2

This is an updated version of a simple program that I wrote almost 2 decades ago.  I've expanded it and given it plenty of new features.  Read more here.

Wide Boy Replacement ROM: Wide Boy 2

This is a replacement ROM for anybody who has the Wide Boy peripheral for the Famicom. Without the peripheral, you can't really get much fun out of the ROM, but there's an example NES file in here for you to play with if you want to.

* Runs entirely in NES' RAM ($000-$7FF) for hot-swapping
* Allows full adjustment of the palettes for the GB screen
* Has a screen-recolouring function a la Super Game Boy on SNES

Rocky icon by Chris CPro Action Rocky Dec/Encoder


This is a program that decodes and encodes cheat codes for the Japanese "Famicom Pro Action Rocky" device.

Instructions and source code are included.

Check out my Rocky Page HERE!

FDS Disk Listing Program

This is just a small program that will list the disk contents of any valid FDS disk, giving some information that is stored on the disk. It works best on a real FDS+Famicom system.

Otherwise, you'll need an NES emulator that supports the FDS system!

First FDS Test programs

These are just a couple of small demos that work on the Famicom Disk System.

The first is a player for the music to "Ai Senshi Nicol" on the FDS, but it also provides a visual display of the FDS' WAVE RAM residing at $4040-$407F. If you try this out in an emulator, and you don't see anything moving, then your emulator doesn't support reading from the WAVE RAM, as it is supposed to.

I also converted my "Stars SE" demo to work on the FDS. (Whoopee!)

Super Famicom Prototype History *new*

These are some line/pixel drawings that I made to illustrate how the SFC's design changed from its first announcement to final release.

A clickable panorama is to the left. Larger pics are here: Pic1 Pic2 Pic3 Pic4

Windows Software
FDSList - A program that lists and extracts files in Famicom Disk System disk images. Now supports the FWNES .FDS file format, as well as conversion between the 'iNES' and 'FWNES' FDS formats! Read the documentation for full details.  C source code included.  (Also see my other old "software" page.)
FDSList 1.4 for Windows is also now available, adding RAW (headered) file extraction

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