Has Moonsweeper ever been fixed in emulation?

[Keatah]

Has Moonsweeper ever been fixed in emulation? Or maybe this is a problem with the rom dump itself? There's graphics corruption in the lower-left corner of the screen like so.

[Ikrananka]

The graphic glitches in the bottom left of the screen are also there with an original cart on a real ColecoVision.

[Keatah]

One would think that such a glaring mistake would’ve been fixed. I mean it’s not like a sneaky thing that shows up under certain conditions.

[pearsoe]

Cleaned up the graphical glitches in the ROM. The weird red square in the upper left, the wrong characters in the lower left. The fuel gauge update glitch was already fixed in the ROM I had.

 

 

Moonsweeper (1983) clean.rom

[Keatah]

Looks good. Thanks for that!

[zyzzle]

That's great! Thanks very much for fixing a 35-year-old problem. I love when people do that.

[Tempest]

Huh, how did that go unnoticed for so long?  What was the problem?  Is this another case of the rom being corrupted or just bad programming?

[Ikrananka]

16 hours ago, pearsoe said:

Cleaned up the graphical glitches in the ROM. The weird red square in the upper left, the wrong characters in the lower left. The fuel gauge update glitch was already fixed in the ROM I had.

This is awesome and I'd like to include this in my CV ROM Update Project.  Could you shed some light on how you fixed the game for my project documentation.

 

One other thing, could you post the original ROM file that you used as your basis.  That would help a lot.  Thanks ?

Edited October 7, 2021 by Ikrananka

[pearsoe]

Attached is the ROM I started with.  It doesn't have the fuel gauge update graphic issue shown in the screenshot by Keatah.

 

The Moonsweeper ROM has two 768 byte name tables stored; one at $ACFF for the galaxy selection screen and one at $B43F for the game play screen.  Both of these name tables had to be edited.  Basically the problem with the graphics was the wrong pattern generator was being used. I edited those name table entries to use (what I thought) should be the correct patterns.

 

If you open the attached ROM and the updated ROM (attached above) in a hex editor and perform a compare you can see all the differences.

 

To answer Tempest's question I believe Ikrananka mentioned the problem exists in the released cartridge so I don't think it is from a bad ROM dump. Probably just bad QA before release or a rushed release.

Moonsweeper (1983) (Imagic).rom

[Tempest]

2 minutes ago, pearsoe said:

To answer Tempest's question I believe Ikrananka mentioned the problem exists in the released cartridge so I don't think it is from a bad ROM dump. Probably just bad QA before release or a rushed release.

The title screen has a Coleco copyright as well as an Imagic one.  I wonder if Imagic had the chips made or sold the program to Coleco and they had the chips made.  The reason I wonder about this is because Coleco already had one buggy rom issue from whatever rom manufacturer they were using, I wonder if that could have happened again?  But from  what you're saying it sounds more like a bug in the program than a corrupted rom.

[Ikrananka]

14 minutes ago, pearsoe said:

Attached is the ROM I started with.

Perfect, thank you so much.  The original ROM you started with matches the one in my CV ROM Update project which is a verified dump from original carts both with colour and black & white labels as well as matching the ROM dump from the European release.

 

22 minutes ago, pearsoe said:

It doesn't have the fuel gauge update graphic issue shown in the screenshot by Keatah.

 This is really interesting.  I have ROMs from quite a lot of different online collections as well as various peoples personal collections and NONE of the Moonsweeper ROMs that I have have the fuel gauge graphic issue either.  So, I have to wonder where Keatah's ROM came from.....

 

25 minutes ago, pearsoe said:

The Moonsweeper ROM has two 768 byte name tables stored; one at $ACFF for the galaxy selection screen and one at $B43F for the game play screen.  Both of these name tables had to be edited.  Basically the problem with the graphics was the wrong pattern generator was being used. I edited those name table entries to use (what I thought) should be the correct patterns.

 

If you open the attached ROM and the updated ROM (attached above) in a hex editor and perform a compare you can see all the differences.

Fantastic info - thanks for that.  If it's okay with you I'll quote and credit you in my project when I update it adding the new "clean" ROM.  I can see doing a compare that there are only 9 bytes difference.

[Ikrananka]

25 minutes ago, Tempest said:

The title screen has a Coleco copyright as well as an Imagic one.  I wonder if Imagic had the chips made or sold the program to Coleco and they had the chips made.  The reason I wonder about this is because Coleco already had one buggy rom issue from whatever rom manufacturer they were using, I wonder if that could have happened again?  But from  what you're saying it sounds more like a bug in the program than a corrupted rom.

The title screen on all of Imagic's ColecoVision releases shows a Coleco copyright notice.  Not sure why this would be but this isn't reflected on the game boxes or in the game manuals, although oddly on the back of the North American silver boxes it does state "Approved by Coleco Industries".  Regardless, on each cart label for every release it states "Program Contents, Audio Visual Display, Cartridge Design and Label Copyright IMAGIC...".

[Ikrananka]

Thanks to Keatah for highlighting this problem, and to pearsoe for fixing it, I have now updated my CV ROM project to include the fixed Moonsweeper ROM.  Thanks guys ?

 

Check out the project via the link in my signature.