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dav000616
9th March 2008, 11:36 PM
Konami Frogger Bootleg

Brought this off ebay 12mths ago and almost got burnt on the deal but thatís another story. Hooked it up and got nothing but a blank screen. The board layout was identical to the sega frogger schematics so I used this for reference. I hooked up my sega board and made note of the control pins on the cpu. For memory there were 3 pins, BUSAK, BUSREQ and WAIT that were different.

WAIT was held high instead of high low pulsing so I started here. Traced Wait back to a 74ls161 at IC82 which has pulsing inputs but no outputs. Piggybacked a 74LS161 and turned it on, still didnít have a picture but the outputs were pulsing now and I saw a small horizontal flicker of video so I cut the 161 out and soldered in another and it now lives.

Arcade King
10th March 2008, 07:04 AM
Well done, thanks for sharing your log.

dav000616
10th March 2008, 11:10 PM
Thanks Trav, there is a minor sound issue when the snake appears the sound level seems to drop low. I haven't taken another look at it but i think it may be a cap in the sound section.