Bubble Bobble

tendril

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Does anyone have the bootleg marked 'CAT NO. K70' ? If so, I'd appreciate some pics of both boards to see how they compare to mine :)

I got this board a while back as not working, and found corroded tracks, warped pcbs, liquid damage to the ROMs/sockets. I thought it was otherwise complete though, but I'm beginning to wonder if a previous owner stripped it for parts, making my job even harder.. There's no capacitors/diodes on any of the inputs. On the bottom board, no pull-up resistors on the graphics ROM data bus. Smoothing caps seem to missing. So I'm not sure if this was a previous owner, or the bootlegger REALLY cut corners in getting this out there. Another interesting difference is a 27c512 has been used in place of two 27c256's - both for the main program, and in the graphics. I've already found bad TTL chips on both boards, but all I've ever got this to display are green lines (palette ram and related are tested good though).

I'm concentrating on fixing the video board to display something other than lines by running with the main program ROM removed - on the assumption this should actually display proper random tiles. Can anyone with a bootleg or original actually confirm this though (pic? :)) The reason for this approach is I don't know if the CPUs are running properly at all, but they certainly clear the graphics memory early in boot, which doesn't help to debug the graphics.

So if you do have a board, just pull the program ROM that you can see missing in my pic and see what happens :)

D61652C9-F96C-435B-ADD6-9FA781A652BB_zpse5zq5rwi.jpg
 
I don't have your board, but I'd try coding it with a BB3 at IC47. I'm guessing the 512 at IC45 concatenated 4+5 together (4 is where that missing socket would go in IC46 on other bobble bootlegs). Have you tried comparing IC45 against romident?

What's the back board look like?

Best of luck!
 
Yes, done that already - after I did that and replaced some other chips on the top board, logic probe shows activity on all 3 CPU's - so the game _might_ be running, just the video board is bad, hence me concentrating on the video side for a bit.

What brings some uncertainty though is the original IC45 was corrupted, so I don't have a good reference in case this board originally ran code not in Mame.

Back board is pretty standard looking (same as other boots).
 
Yes, done that already - after I did that and replaced some other chips on the top board, logic probe shows activity on all 3 CPU's - so the game _might_ be running, just the video board is bad, hence me concentrating on the video side for a bit.

What brings some uncertainty though is the original IC45 was corrupted, so I don't have a good reference in case this board originally ran code not in Mame.

Back board is pretty standard looking (same as other boots).

If I can make a suggestion, in your EPROM reader, select 27C256 as the type and then read the first 16k of the chip, that should be BB4 and romident should be able to verify it. Or get bb4 and bb5, in windows copy /b bb4+bb5 bb4and5.bin, then verify that against the contents of that IC45 - that'd confirm the idea that they merged it.

Ribbon cable on these things has been an issue in the boards I've looked at, making video cut out if loose or bent poorly. Verify that?

My boblbobl repair log found one of the TTLs was trashed, making the addressing of the graphics roms useless; also had a few bum roms on the graphics side. Perhaps check that?

Good luck!
 
Appreciate the help :) But as above my IC45 was corrupt when I got it, I have no doubt about that. I've also found at least 6 bad TTL on the bottom board so far, and at least 2 on the top board. (Like I said - this board was really trashed!).

What I could really use though is a screenshot of what your board does with the IC45 removed :) So I can verify what the video circuit is meant to look like without the CPU doing anything. I'm assuming the usual random 8x8 tile look, but I don't know for sure. When I do know video is at least roughly right it's much easier to go back and debug the CPU side.

I'm hoping it doesn't look like this:

E468B449-1B4D-4B45-8E4F-9335719F4C61_zpsiolmjadd.jpg
 
Here you go, not complete matches with your screen, unfortunately...

I pulled each of BB3, BB4, BB4+BB5, and BB5 and then booted the board.
Missing BB3=scrambled graphics
Missing BB4=black blank screen
Missing BB4+BB5=blue blank screen
Missing BB5=Starts splash screen with bad graphics/colors, goes to show secret round screen

Hope this helps.
 

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Here you go, not complete matches with your screen, unfortunately...

I pulled each of BB3, BB4, BB4+BB5, and BB5 and then booted the board.
Missing BB3=scrambled graphics
Missing BB4=black blank screen
Missing BB4+BB5=blue blank screen
Missing BB5=Starts splash screen with bad graphics/colors, goes to show secret round screen

Hope this helps.

Fantastic thanks! Missing BB3 confirms the expected 8x8 tile patterns. One of the first things BB3 does is clear all the VRAM (which is why removing 4 & 5 show blank screens - BB3 does the clear, then the CPU crashed or stopped on missing ROMs). This is why I'm testing with BB3 removed, as otherwise a lot of the graphics TTL's just pulse low all the time.
 
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