AuthorTopic: Colecovision/Others Pixel Art Guide  (Read 3728 times)

Offline BladeJunker

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Colecovision/Others Pixel Art Guide

on: April 16, 2012, 11:02:10 pm
I figured I should cover the big 3 from that era in video gaming history, Atari 2600, Intellivision, and the Colecovision. :)

Let's start this by discussing the history and status of the Colecovision in North America at least as others will have to comment on what kind of hold the Coleco had in their regions, so speak up and contribute if you own any of these systems now or when they were new. ;D

The Colecovision came late, to be specific it just got started when the Video Game Crash occurred which resulted in a premature loss of the usual time game developers have with a console where software improves gradually up to the end of its life cycle and the games get the benefits of much trial & error when people experiment and discover the unique strengths of any hardware. So the surface was barely scratched on what the Coleco could do when pushed to its limits. I played Colecovision back in the day but did not own one however I still think it got the short end of the stick having so much squandered potential.

However the video hardware and CPU range used in the Colecovision did not go unused elsewhere as the MSX1, SG-1000, Coleco's ADAM computer, and the TI-99/4A made by Texas Instruments which manufactured the major chipsets that went into these systems. The TI-99/4A computer generally had a longer status having came earlier than the Colecovision as well as the MSX1 computer which sold very well in Japan. From what I've read the SG-1000 was primarily sold in Japan and parts of Asia so it didn't make much of a splash globally.
Subsequently the MSX1 is the best pixel art reference in general followed by the SG-1000 because of the wealth of games made for it as well as that the Japanese spent more time with it as an art form while American developers tended to mostly pursued a more basic approach to graphics back in the day except for arcade ports. It's mostly homogenized in graphics quality within the homebrew scene today but the MSX1 is still the front runner as far as reference goes with porting of past MSX1 to TI-99/4A since it has a fairly large backlog of quality games only released in Japan.


*Fun Facts:Coleco (a contraction of COnneticut LEather COmpany), makers of the Cabbage Patch doll.

Video Chips to Consoles:
SG-1000=Texas Instruments TMS9928A

TI-99/4A=TI TMS9918A VDP (TMS9918 in the earlier 99/4, TMS9929/9929A in PAL versions. Distinct in being the only chip on the TI motherboard which had a heat sink on all models. Early models also had a heat sink on the clock generator, the TMS9904.)

Colecovision=Texas Instruments TMS9928A

MSX1= Texas Instruments TMS9918


CPU, sound hardware, and performance differ between these 5 systems to a degree that I can't comment on as of yet but the basic graphics limitations match primarily the screen resolution and color palette.

The screen resolution is 256X192. Decent amount of pixel resolution and no analog stretch required since it is 4:3 by default.


Here is the color palette which is fairly close in my opinion as I own a Colecovision and a TI-99/4A. 15 colors available with the 16th reserved for an alpha channel.

Also here's a person who interpolated an RGB palette from his ADAM computer which looks the same as the one listed here so I think its legit.
http://users.stargate.net/~drushel/pub/coleco/twwmca/wk961118.html
It has that same de-saturated look of the C64 palette but its not nearly as balanced, however I think it has a charm to it. ;) I haven't tried it much so here's a cool pixel art I found to demonstrate its color potentials. ;D




Sprites:
-32 sprites at once out of a library of 64.

-4 sprites per scanline by default.

-Sprite can be 8X8 or 16X16(All must be the same size.).

-1bit color so opaque and alpha, layering to increase colors per sprite which in turn uses sprites. Here's a good article about layering Coleco sprites effectively.
http://www.siggraph.org/publications/newsletter/v32n2/contributions/molyneaux.html
*It aggravates me when those that feature pixel art uses JPG format, it bugs me even more when the block compression is set this high. All web browsers support GIFs right and at least most support PNGs. Oh and don't get me started on pixel art resampled to incompatible resolution scales. :yell:

-Only 2 colors per 8 pixel wide line.


Scrolling:
Yes it can scroll but to do so smoothly requires special coding in the engine otherwise it will simply jump 8 pixels at a time by default which is jerky.


Haven't had much time to delve into Coleco matters with the 2600 and Intellivision research still in progress but here's some links to related content that will inspire you for now.
http://msxdev.msxblue.com/?page_id=275(Nudity warning, one game has a naked dude.)
http://www.msx.org/forum/msx-talk/software-and-gaming/possible-gng-remake-msx?page=2
http://www.generation-msx.nl/msxdb/softwareinfo/3156
http://www.youtube.com/watch?v=PMbqf-SpYS4
http://www.mobygames.com/game/msx/playhouse-strip-poker/screenshots(NSFW, nudity warning)
http://www.mobygames.com/game/msx/strike-force-harrier/screenshots
http://usuarios.multimania.es/tulacki/msx/
http://www.digitpress.com/library/interviews/interview_steve_zedeck.html
http://www.msx.org/forum/msx-talk/software-and-gaming/popeye-msx?page=0
http://boards.openpandora.org/index.php?/topic/102-recommended-best-games-on-msx/
http://www.icongames.com.br/msxfiles/blog-en/2008/07/17/sg-1000-re-convertion/
http://chipmusic.org/forums/topic/4103/pixel-art-tools-and-related/page/5/
http://www.msx.org/forum/development/msx-development/wondering-how-smb3-would-look-msx1?page=4
http://www.msxblue.com/?p=3513&lang=en

In many ways I don't think there is as much to explain with Colecovision graphics standards since its pretty easy to understand so I think most further posts will just involve experimentation with the palette. This is why I added this long list of links to wet your appetites. :D

Here's a homebrew I quite like called Ghostblaster made by a fellow Canadian Daniel Bienvenu AKA Newcoleco, great stuff with full scrolling and level editor plus a trim level export format.


Download Ghostblaster:
http://ccjvq.com/newcoleco/

Newcoleco's Youtube channel:
http://www.youtube.com/user/newcoleco/videos?sort=dd&view=0&page=8
Talented guy, lot's of good videos to watch including game development for Coleco games.

And the Coleco Homebrew Scene:
http://www.colecovision.dk/homebrews.htm
« Last Edit: May 27, 2012, 07:22:14 pm by BladeJunker »