CV Gus

Hello again, all! It's been too long... Years ago I modified some CV ROMs with...I'm not 100% certain any longer. YYCHR may have been one of them. I do not remember how I altered colors, or if I used a Hex Editor as well. Like below: Can anyone give instructions how to do this?

What's amazing is how, even with using limited colors, how good the backgrounds look. This is amazing.

Bomberman looks very impressive!

Well, I'm back. I was wondering how the new and improved version of Mr. Do! was coming along. Also, is Mario Bros. available for sale? Gradius? Thanks.

Hope things are going better for you by now. Good luck to you.

I take back the "not bad" comment- now that I've seen the video, it's really quite good! If a version for "regular" ColecoVision comes out, well, it's on my list.

Well, I already know about hexdecimal and CV colors, and the Omega Race screenshot shows that I can change screen color using trial and error- but since certain color coding could appear in three or even four ways, there could be a couple of hundred such numbers; surely there's a more efficient way of doing it? I'm currently redesigning the Amoeba in Boulder Dash so it can be multi-colored, but I have not yet figured out how colors are changed from screen to screen yet. Obviously it is not simply by a new set of numbers. In Frogger, I've made the logs and vehicles look better, but still haven't tracked down the alligator's colors; the only ones that look like they might have nothing to do with it- is it even a custom character, I wonder, or a sprite, as unlikely as that might seem? The only way to get the frog to look better is with an extra sprite, as in Mr. Do! Even now, I much prefer "my" version of Boulder Dash to the regular one. Likewise Omega Race. CV Centipede would require shifting the works to Mode 2 and then figuring out how to code in the colors, which would be more extensive. Now, how does one "disassemble" a ROM? Can it be done in a way that Newcoleco's software can change it back into a ROM again? Or would the disassembler do this too? Where would I get the software? And where are instructions for coding CV games in C, like what Newcoleco's programs use?

So far, I've had some luck altering the appearance of certain games, most noticeably Omega Race and Boulder Dash. I'd actually like to get them put on cartridge. This is done using Hex Edit, and some logical guesswork. But I have NO IDEA how to find the parts that determines Screen Color (except by trial and error) or SPRITE COLORS. Can anyone help me here? I'm also trying to alter the look of Frogger, but have had zero luck with the alligator's color. THE most important thing, though, would be a way to take a ROM and instead of a series of hexadecimal numbers "re-translate" it back into something one can actually read. For example, I'd like to make Mr. Do! a two-color character by adding a new sprite, but a jumble of numbers tells me nothing. Thanks in advance!

One game I really liked when I played it on a Commodore 64 was "Boulder Dash," and was pleased when I could get it for the ColecoVision. I never liked the looks of Rockford, though. Luckily, since all characters are apparently custom characters, I was able to change appearances- mainly color, but a few other details as well. Here are some screenshots. It seems as though a formula is used for some of the colors, based on Rockford's initial colors. This is why the Amoeba screens have different colors. I also gave some shading to the boulders.

Thanks for the help! Guess part of my problem is that I'm trying to reverse-engineer someone else's work. I knew that Centipede was Mode 0 by changing the hexadecimal number and seeing that EVERYTHING changed; but how would you find "10000" in an existing program? "0x27" does not exist in the program, does it? Or did I just miss that (I'm new to this). It's obvious that altering Mr. Do!, even just making Mr. Do! a two-color character, is not going to be easy. Adding a (red) sprite, and moving it along with the white image, looks to be a real hassle. At the very least I'd like to know where the color codes for the prizes are, since I want to alter them, too.

Latest Omega Race update: Still trying to find the color codes for sprites. Still, it is coming along nicely, and except for the fact that an 8x8 grid makes trying to make the player's ship like the arcade version impractical, I actually like the way it's turning out. How would a CV deal with numbers above 255? I had assumed that one space would be x256 and the next 0-255, or vice-verca, but trying to find "10000" in Centipede this way has not worked. Also, I need to find out more about the VDP- any links?

Although it's mostly guesswork with things like the color code, here is what I've managed so far: (See images) None of the literature I've downloaded explains things like where numbers are stored, so I do not even know how to change screen modes, let alone how to get better-looking images for Centipede in Mode 2, which would need more numbers for a given character! Since Centipede is in Mode 0, this is the best I can do so far. And forget at this time adding a sprite to make Mr. Do! or your gun in Centipede multi-colored. But keep in mind I only really started just yesterday, and the problems here are very distracting.

I've figured out a few very basic things so far for existing programs. Unfortunately, instructions for actually programming CV games, which would help with alterations, are very hard to come by. The YY-CHR program, when in two-color and vertical modes, has been VERY helpful indeed. This is what I've managed so far: Omega Race alterations were a hassle and a half, until I guessed that the purple areas were not purple objects, but the screen color itself. This narrowed things down enough to guess at the places where the color was stored; there were two places, one for game sessions and one for the game over part. Object alteration is not too difficult, although since everything seems to be 8x8 instead of 16x16 it's unlikely I'll get the player's ship to look like the arcade version. Oh, well. I'm still trying to track down all of the color codes, I have a couple so far, as you can see. I should be able to get a nice vector look for this one. I had wanted to do monochrome, but since both player's ships look alike I'll probably go with color, or maybe monochrome except for the second player's ship. Centipede: if you look up at an earlier post here you can see my design for a better-looking mushroom. Sadly, it's now obvious (although I do not know where the memory locations for setting screen modes are, or what the numbers should be; none of the Z-80 literature even mentions this) that the game is in Mode 0. The only way to make it look better is to put it in Mode 2, and that will also mean more numbers will be needed for each character (eight times as many). How to do that is still beyond me, but it's painfully obvious that anyone skilled enough to program this game was also skilled enough to make it look better- why did they then make Joust, Pac Man, and the other games better but not this one? Question: if I do manage to get this all done- and it's almost certain with Omega Race, what you see here is not finished yet since I only caught on yesterday- might they be put on a cartridge as an "improved collection?"

Where would I download YY-CHR? and instructions for programming Z-80? Medical emergencies here give me no time for searching.

Thanks for the reply! I stumbled across that later that night... Right now I have two medical emergencies in the family to deal with, so I cannot be out very often or for any length of time. Therefore if something isn't obvious I have to ask about it when I can and hope an answer (if I haven't figured it out) will be there the next time. My posts may well be "out of sync" for those reasons. The instructions claim you can alter the code directly but although the indentation appears the hexadecimal number always reverts back to the original. How do you deal with that? And is there anywhere one can find any instructions on coding? It is a bit- just a bit- like Javascript, but not nearly enough.

How do you use the debugger in BlueMSX? I have to put it in CV mode to get the ROMs to work, and when I try to use the debugger, I'm told that "Disassembly Unavailable."

"Syntax Error" usually means what amounts to a typo- as far as the computer is concerned. I've matched what you have against what I have and cannot see what the problem is. I don't know which version you are using- I'm using the 2013 compiler since this is a Windows 8 64-Bit ASUS- but I'll try to attach the files Daniel Bienvenu included with both compilers right here for you, although you probably have one of them already: The first is for the 2013 version, the second for what I guess is the earlier version; maybe the two together can help out? readme.txt COLECO.TXT

As of right now, I have gotten the Virtual ColecoVision emulator to run, as well as Daniel Bienvenu's tools and a compiler. I've already programmed-semi-hacked a minor CV ROM. Not too impressive, but it's more than I could have done last week. One thing I want to do is to improve Mr. Do!. I would redraw the Bad Guys and maybe the Alphamonsters (the latter looking like those from another hack here); they'd all still be single-colored, just better drawn. Possibly change the apples' colors in certain screens so they stand out more. Yellow, blue as well as red. In the green screens, for example, they'd be yellow. If possible, add drawings to the EXTRA MR.DO! screen- small and static, just pleasant. Nothing spectacular. The real tricky part: Make Mr. Do! a two-color character. This would mean adding a sprite to the game (hard or easy?) and altering the existing character by removing the parts where the red sprite would be superimposed. But if that Mr. Do! game above is going to be a reality, and it does not require the Super Game Module, then count me in for it. It looks GREAT.

My first ROM using the afore-mentioned tools, and a simple-simple bit of sound... Hey, you have to start somewhere. ToddMusic.rom

My very first, and obviously simplistic, true ROM: ToddMusic.rom

HELP! So far, within the past 1 1/2 weeks, I've finally managed to get the Virtual ColecoVision to work- it plays most games. I downloaded some CV tools, and today managed to finally get the compiler CC13.EXE in the CVDEVKIT_BUILD_20130720 working well enough to compile some of the test programs, but not the "Rebound" program in the CV PROGRAMMING PDF file- maybe copying and pasting it won't work, but at least nothing crashed, all I got was a black screen. But if someone wants to alter a ROM game file, how would one go about it? What do you use to read it? A Hex Editor seems a bit klutzy, how do you find locations for determining what sprites look like, adding a sprite, that sort of thing? Daniel Bienvenu's video helped a little, but I need a place to start. Thanks.

How does one read the program? I'm not sure a hex editor will do here for that- is there something that can translate a ROM file into something more understandable?

Interesting hack- if I ever get the hang of this, I'll probably use your Alphamonster design. How did you get to "see" the program, and how did you find the locations for altering the images? What were they? If possible, I want to make the Bad Guys look better, albeit still single-colored (Ladybug, Mario Bros., Cosmic Avenger, etc.); I may change the apple colors for certain screens, for better visibility; maybe add images for the EXTRA MR. DO! screen; and- the tricky part- adding an extra sprite to make Mr. Do! into a two-color character. So far, with a crummy CE 6 netbook's Hex Editor, I sort of made some text changes in Omega Race. It worked about 50% of the time, at least.

I downloaded a few programming tools done by Newcoleco, but those will not run on a 64-Bit ASUS. Of course, trying to alter anything with Notepad++ always results in a disaster, so- can anyone direct me to tools that will work? The documentation is excellent, so if Newcoleco has anything I don't know about that will run on this thing, better yet! There was one thing that did run- it takes an image and "translates" it into what a CV would do. The folder downloaded is called "Z-80," by the way.

Superb- I managed to get the "Virtual ColecoVision" running on this thing, and did download- and even run!- some homebrew ROMs, which is further than I have ever gotten so far, especially after some mid-2000s efforts. Now I need to know where I can download some "regular" CV game ROMS from a SAFE source; the only ones I found always end up with a malware site warning, so I will not use them. Aside from simply changing the appearance of Omega Race, I also want to change some appearances in Mr. Do!. Altering the Alphamonsters and Bad Guys will be easy enough once I figure out where the actual numbers are (just like in Moon Patrol), but the real challenge for me will be Mr. Do! himself- I want to superimpose a red sprite on him so he becomes a two-color character. Also, when you earn a bonus life, maybe include a couple of images to echo the arcade version- nothing awesome, just enough to be pleasant. Now I need a safe source of ROM files, and the means to read them. I have found some information on memory locations, so with Virtual ColecoVision running, at last there is at least a start. Thanks!