I already had one board with 'Sakowa Project Korea' roms and this one looked the same. I could use the working one to troubleshoot this board, that was the idea.
Previously.. :
Having read the Bubble Bobble Redux thread, i set about to make my (working) Winter Bobble pcb display the Toaplan logo, and proper copyrights. These bootlegs are 99% perfect copies, but they replace the original gfx decoding chip with some custom ic's, and use decrypted/another format gfx. (The original Toaplan roms/gfx dumps won't run on this hardware.)
I tried to get the original rom working in Mame with the bootleg driver, and it seemed well, but gfx were corrupt. Manual patching and accidently breaking rom #1/2 and 3 i managed to get it semi-working, but with corrupt levels. So i gave up.
If i couldn't get this to work, it would be a treasure trove of eproms at least, with a free 68K, Z80B and some logic thrown in as well. All eproms were socketed anyway
A (sloppy) visual inspection didn't give me much hope, the board looked perfect at first, nothing broken off, no missing parts, and no damaged traces.
It was already late and no daylight stopped my visual inspection. I find proper lighting to be very helpfull to find defects like this. A magnifying glass and desk light just doesn't cut it for me..
Next morning i didn't inspect the pcb further, but fired it up in my testrig. To my surprise, the board booted fine, and showed a proper 'Snow Bros' main screen, and Toaplan logo with all the right copyrights. But, the stages were completely broken..
I figured someone had, at some stage, replaced eprom #1 and #3 with different versions. But in my tests with Mame, this never worked properly. So i had some wierd revision of the board, with wierd roms. Maybe the wrong ones? Just like my own hack attempt to restore copyrights, the stages were broken.
Further evidence was that #1/#3 were aftermarket burns with no stickers on them.. So, it seemed like case closed, wrong eprom 1 & 3..
I swapped in #1/#3 from my 'winter bobble' bootleg and booted the board again. Still, it showed the same corrupt graphics..
Then i remembered also hacking around in rom #2. So i look closer at that rom.. And this is where i botched up the visual inspection the day before.. At some point in this game's life, Rom #2 had been whacked on the rightmost side, and pin #14 made bad contact, was bent into pin 13. A check showed the rom didn't make any proper contact at all. i gently removed it, but pin #14 was snapped of and stuck into the socket
. I confirmed the same error with the stages, when rom #2 was left out of the board to be sure.I soldered a bit onto pin #14 and bent the rest of the pins carefully back into place. A quick & dirty fix so far. Pin #14 made contact with the socket, verified contact with multimeter
Game now works 100%, with proper copyrights and all!
Todo:
- Solder a socket or proper leg replacement onto rom #14 - DONE
- Clean up the layer of crud on the board. - DONE
- Dump roms 1/2/3/4 so we can have proper copyrights on other bootleg boards as well
-DONE (Download here.)The version from the above download does not run on original boards, only on 'winter bobble' boards with sakowa copyrights. wb1 and wb3 are the files to use. They work in MAME as well
So, in short, this purchase saved me a hackjob, and i now have two working as original Snow Bros boards.