Tuesday, 6 November 2012

1943 (bootleg) - Repair Log

1943 (bootleg) - Repair Log

Just got back from the pub with a fellow member of J+ ..who has kindly set me up with this fixer-upper 1943 bootleg pcb (Nice to meet you dude! & Thanks again mate!)..

Initial reports were of no-display & partial audio response, a quick look over the board revealed some cracked solder joints on the primary capacitors (the big fekers in the far left) - and a suspect patch wire near the Jamma connector..

Cleaned her up, eyeballed the soldering & removed the patch wire which seemed to wire the second coin button to a severed track (that would have carried the 1st coin switches signal).. 

Installed a new patch that connected the coin-signal to the service switch (which is how I coin up all my other boards) & powered her up... but.

Nada.. Ziltch! :'(  ..Got nothing initially. 

But remembering how my bootleg copy of Twin-Cobra behaved, I took a risk and turning the 5v voltage up (slowly!) on my adjustable supply ... :S (always tense time doing that!) ...

And wouldn't you know it.. Bling!!! At 5.9v she woke up out of her slumber. ¦)

Forgot how basic this game looks after hanging around Twin-Cobra & the R-Type's!!

Its got a very distinctive Red, Green & Blue palette... But come on, what other game has a Tsunami as a power up?!! Oooh Yeeah... :o)

And the twin sound chip setup in this game is mental! :D Esp. when the continue music plays over the top of the background tune! It gets crazily busy!!

The stories not over though...

Playing further into the game I noticed that the back-ground tiles above the sea (& below the clouds) had some corruption as they passed by certain regions of the screen.

However, the corruption clears up when the tiles reach the bottom of the screen!

This feels like a RAM issue.. and not all of it, perhaps just the chips responsible for the middle section of the frame-buffer!?! :/ Hmmm..?

Edit: aha.. It's not all of the BG-Tiles that are broken.. There is one island that scrolls by intact!! Rom then? (or both?)

But it's bed-time now... I'm going to have to tackle Level 2 another time.