colecovison I disassembled Mr. Do!

[Captain Cozmos]

I am cleaning it up now and identifying some memory locations before I post it.

 

The usual disclaimers and pleasantries such as do not sell my work....
I can not stress how much I love THANK YOUS, TROPHIES, PROMOTIONS......

This was done for learning as well as sharing with the community.

Speaking of, I have put forth an olive branch to the MSX community with my work.

If you go over to the MSX resource website they talk about using wrappers, for some reason, to get games like Smurf to run on the MSX.
Why..., just disassemble, adjust for your system then reassemble it.
Easy to do on the MSX which has enough ram.  MSX to Coleco, well you know the deal.  I may change that in the future.

If an MSX rom does not use more than 1k then I may be able to port it.  Even if it does use more than 1k that also does not mean it can not be ported over.

Considering that they did all of this in the 80's, I am flabbergasted as to why more games were not on the Colecovision without the extra hardware....Either way, that's for a rainy day.

 

As far as Mr. Do!
All links accounted for.
All Sounds have been identified and cataloged.
Some memory locations as well

 

Several unused routines, mostly concerning sound, have been removed for a grand total of 21,331 in size with the original at 24,576.  A total savings of 3,245 bytes.

 

That is over 3k and your telling me that they did not have the space for two extra screens like when you get a diamond or a picture on the EXTRA Bonus screen?  They already had the space because they could not use anything less than 3x8k proms without losing something in the game.

Maybe I will add these before I release the code.  Or have the release and my patch.

 

So basically there are 5 major tables that encompass the 10 Phases (levels)

the first load Extra and Blue Munchers behavior int ram

then the Apple Placement

Then the Cherries

Then the Playfield Patterns

Then the Playfield Colors

Then the Spites

They are listed in that order in the source but "not necessarily" called in that order

 

The game is mostly made up of Sprites with maybe 64 patterns to the entire game.

 

I've identified the placement data for the levels and now I am trying to figure out the structure.
I have 100% no doubt that you can make a level editor for this but there is only so many ways to draw in 32x24 where 3 of those rows are used for the hud.

Once you get the source I am sure you can create levels and change the sound to suit your needs as opposed to Smurf which would take a bit of work.

 

So, I will release something, sometime soon.  I'm just incredibly busy and I also promised the wif that I would make spaghetti tonight.

If anything you should take away from all of this is what you call "A BREAK"  Don't ignore your family.  It's just a computer.

CPT Cozmos

 

 

 

edit:

My earlier assessment about the new rom size was 21,331
I scoured the source to find and addition 55 bytes.

Now the rom size is 21,276 with a new savings of 3,300 bytes.  More than enough to add content and stick within a 24k rom.

 

Edited November 9 by Captain Cozmos

[GraffitiTavern]

Thank You!

[Tempest]

I was always disappointed with Mr. Do on the Colecovision.  It's better than the 2600 port but that's not saying much.  I feel like they could have done so much better.  I guess I was spoiled by the great computer ports.  I grew up with the Apple II version and it's much better than the CV port which usually isn't the case.

 

Other than the unused sound routines, was there anything else interesting hidden in the code?

[ColecoFan1981]

Good work so far, Coz! As Tempest just said, may I please ask what discoveries you had found in the code?

 

~Ben

Edited November 10 by ColecoFan1981

[Captain Cozmos]

34 minutes ago, Tempest said:

I was always disappointed with Mr. Do on the Colecovision.  It's better than the 2600 port but that's not saying much.  I feel like they could have done so much better.  I guess I was spoiled by the great computer ports.  I grew up with the Apple II version and it's much better than the CV port which usually isn't the case.

 

Other than the unused sound routines, was there anything else interesting hidden in the code?

Nothing worth talking about.
The sounds were repeats of what was put in other places.  I guess they just wanted to get it out the door.

There is enough room left over to add the rest of the treats.  Technically, to run on stock you would have another 11k or so to reach 32.

 

I honestly think that the ball could gave been bigger but that might be smaller for mathematical purposes and collisions but I did not study that too much.

 

Right now I am trying to identify and label the scoring.

There are no BCD style statements so I have to delve a little deeper.
Once the memory locations and scoring are identified then I'll release the source.

I recreated as close as possible the first level of the Arcade stretched screen, in Tony Cruise Tile Editor, just to see if the right side could house everything.  It can but it would be different in that the EXTRA would go up and down and everything else would fit somewhat.  The real question would be is it worth the trouble.

I suspect that just changing the levels with the existing code, maybe adding more treats to the center and other missing content like the bonus screens would be about the extent of it.  It can be done for whomever wants to take up the challenge.  Maybe even add the apples to the Blue Munching things when the walking letter is hit.

 

O3 Cozmos

Edited November 10 by Captain Cozmos

[Captain Cozmos]

Actually, I did find this one sprite I can't identify as something that has ever been on the screen.

Maybe you guys?

 

 

Every other pattern, sprite and sound has been identified.

Edited November 10 by Captain Cozmos

[Pixelboy]

Looks like an enemy character pushing an apple. Don't some enemies do that when you get far enough into the game?

 

[Captain Cozmos]

I'll take a look.
So far I've been trying lower levels in order to track down certain values.
 

 

 

edit:

Tried even at level 4, they just push that apple out of the way.  Same pattern.

There is no link to it, that's just the thing.  I am at the point where the source has been 100% linked to all data.  There is nothing else other than maybe some type of screwy math to connect to this sprite.  With everything else being standard game code, I can't believe that is the case.

 

This actually could have been? in the process of being implemented and forgot about or not enough time so it could be rushed out for Christmas or some scenario like that.

 

If anyone else has seen this graphic then let me know and I will look at other binaries, maybe we have a prototype?
Anything is possible in this world in which we live.

Edited November 10 by Captain Cozmos

[Captain Cozmos]

Here is a side note that will justify why TOSEC is so screwed up.

I just checked two versions.  The one I have and the [b] version.
They are a 100% exact match except for 1 byte at the very end of the binary that is nothing more than the padding in order to round it off to 24k.

I never relied on TOSEC unless it was a last resort because they will add save game to the collection as if it was an entirely different version.

 

So, if anyone out there has a different version of Mr. Do! for the Colecovision then I will put this down in history as a prototype image that was never used until otherwise.
 

[Tempest]

11 hours ago, Captain Cozmos said:

Actually, I did find this one sprite I can't identify as something that has ever been on the screen.

Maybe you guys?

 

 

Every other pattern, sprite and sound has been identified.

Thats the enemy pushing an apple out of the way.  If they struggle too long with it or get blocked by another apple or Mr. Do then they'll turn into a digger enemy.

[Captain Cozmos]

21 minutes ago, Tempest said:

Thats the enemy pushing an apple out of the way.  If they struggle too long with it or get blocked by another apple or Mr. Do then they'll turn into a digger enemy.

I am on board with you 100%

My issue is that I can not make that work no matter what level or how long I play.
I even watched videos on YT and the same result is that these things just push the Apple out of the way with no change in sprite.
As a programmers point of view, if my guy is going to change then push the Apple out of the way.  I spent a ton of time on that scenario and am not going to have it work only sometimes or on higher levels.
 

The great thing about GearColeco is that you can see all the sprites in real time while playing the game.  Even there I have never seen that pattern show up.  It's not even in the table as being loaded into memory.  So maybe I discovered lost archeology as far as this game and Colecovision.

 

Also, this is being tested on an unaltered source as a reference but going back to my earlier comment, I think it was supposed to do what you are describing but never finished.

 

Is the only sprite in the table that has no link and is just a 32byte pattern on the tail of another but I'll keep on searching while doing other things.

 

 

Edited November 10 by Captain Cozmos

[Captain Cozmos]

Here is another discovery and I challenge you guys to show that you have a working version of this character.

This is how the code looks.

 

 

 

It's obvious that the sprite is for the creature to push the Apple.
A) the creature changes shape and

b) you can see in the code that there is no link to the animation cell.

 

Armed with that understanding, have you ever seen in the history of this version of Mr. Do that animation show up.
If it works on your version then post your binary so I can take a look.

In the mean time, I'll try to find a way to link this in but aside from that I think it was an early concept that did not make it in the game.


If I am right about all of this, I want the history books to reflect this as my discovery.

 

[Captain Cozmos]

I switched the patterns with Mr. do when he is pushing and this is what you get.

 

 

 

I don't know about you but I have never seen this guy before.
He looks like a little alien sitting on a toilet.

[Tempest]

Either this is a dropped idea that didn't get implemented OR it's a leftover sprite from an early prototype that was based on the Japanese version.   In the Japanese version (some say it's a prototype), the main character is a weird white snowman with a rake.  I'd guess that sprite is supposed to be the monster though.

 

https://tcrf.net/Mr._Do!_(Arcade)

[Captain Cozmos]

I might be going out on a limb here but this could also be an early animation of Mr. Do pushing and it was left in.

A three cell animation and what looks to be the ball on his backside like he's holding it with one hand while pushing with the other like in the Arcade.

 

This is what you call detective work.

 

Hidden secrets after 40 years.

I'm going to leave it in the source and label it as Mr. Do unused push animation or something along those lines.

 

 

 

EDIT:

After looking through source with a microscope, I honestly believe this is the final conclusion.

When you look at the final result

with the ball on his tail that it is not one of the bad guys.

and thanks to Tempest from his post below this one, it could have been based off the original Japanese model.
Was it intentional Easter egg paying homage to the original or just a rush job to get it out the door.  I don't know but I would rather write it down in the history books as a found 40 year old Easter Egg than corporate greed to meet a deadline.  Which sounds better to you?  Does anyone know the author of the Coleco Game?  An email?  Alive?  Any way we can confirm or deny?
 

 

 

Edited November 10 by Captain Cozmos

[Tempest]

6 minutes ago, Captain Cozmos said:

I might be going out on a limb here but this could also be an early animation of Mr. Do pushing and it was just left in.

A three cell animation and what looks to be the ball on his backside like he's holding it with one hand while pushing with the other like in the Arcade.

 

 

 

 

 

 

 

This is what you call detective work.

 

 

I literally just posted that a second before you did. Great minds think alike

[Captain Cozmos]

 

17 minutes ago, Tempest said:

I literally just posted that a second before you did.

Cool... Thanks Tempest for bringing this to the table.
from https://tcrf.net/Mr._Do!_(Arcade)

 

Edited November 10 by Captain Cozmos

[Northcoastgamer]

Another strange aspect of CV Mr. Do is the score rolls over around 655,000 not 999,990 like many other CV games. I always found this weird.

Edited November 10 by Northcoastgamer

[ColecoFan1981]

I knew that that mystery sprite had to be the "Yukidaruma" snowman character from the original Japanese proto! Most of the BGM for the CV port was taken from that version rather than the final version.

 

~Ben

[ColecoFan1981]

2 hours ago, Northcoastgamer said:

Another strange aspect of CV Mr. Do is the score rolls over around 655,000 not 999,990 like many other CV games. I always found this weird.

Yes, I've read that the number for the score tile (without the trailing last zero) is stored as a 16-bit ($FFFF) byte.

 

Weirder still, in the CV port the code for the scoring of the bonus food you get in the Badguy Spot keeps on going, too, instead of stopping at 8,000 points from scene 22 on in the arcade release. As this video starts off with scene 59, then the bonus for the food is 30,000 points (also worth three standalone Alphamonster appearances).

 

~Ben

Edited November 10 by ColecoFan1981

[Captain Cozmos]

2 hours ago, Northcoastgamer said:

Another strange aspect of CV Mr. Do is the score rolls over around 655,000 not 999,990 like many other CV games. I always found this weird.

 

It's not a glitch as in a broken system, it was meant to be this way.  Through the source this could be increased but I leave that up to you guys.

 

SCORE_P1_RAM:        EQU $727D ;  $727D/7E  2 BYTES SCORING FOR PLAYER#1. THE LAST DIGIT IS A RED HERRING. I.E. 150 LOOKS LIKE 1500.  SCORE WRAPS AROUND AFTER $FFFF (65535)
SCORE_P2_RAM:        EQU $727F ;  $727F/80  2 BYTES SCORING FOR PLAYER#2

 

Edited November 10 by Captain Cozmos

[Captain Cozmos]

Here is the source

There were 62 more ram references so I did not do them all.  Maybe later unless you get to it first.  Most of the important ones are there.
I added a simple on/off feature so when you compile you do not have to remember was it 55AA or AA55 to turn off the titles.

For the history books, just remember who did this.
It's not an ego thing but it is an I did it and in this retro universe a lot of people like to acquire others credit for their work.
 

You should be able to scramble or alter the code within reason as long as you follow proper assembly language coding practices.
Assemble with drag and drop on TNIASM or through the Dos Prompt.

When I reverse engineer things I label a lot which ultimately leads me to a conclusion like crumbs to whomever stole the cookies.
So, a lot of the labels I am pretty sure are correct and some may be a hunch.
Either way, feel free to dive into and correct something but I ask that you share your findings so we can get a complete picture.

 

Each source I release gets better and this one has been the best one yet so read and learn from it.

CPT Cozmos

Mr. Do! Source.asm