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ForestOfDreams

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So I picked up an aliexpress strider mostly out of curiosity.
I figured worst case I ended up with spare parts and some decent eproms if things didn't turn out.

I also wanted the challenge of trying to un-bodge it and see if I could get it working like factory as a spare A.

The good: It was cheap, and came with an original b off street fighter and a somewhat beat but functional c and what appeared to be a factory new A besides the fact they let the boards rub together clearly which caused some fairly deep but only appearance level gouges.

The bad: They used some type of clone yamaha 2151 and 3012 and there are capacitors in the places of resistors. Also random resistors have been removed from both a & b.
The audio amp is mono minus heatsink and has been powered interestingly along with the 4 legs clipped from the yamaha clone.
Not everything was put back either.

It did work though surprisingly well and sounded right but I had my suspicions things were modified for it to run in code somehow.

My hunches were correct.
Unfortunately I thought to document this after I had already started, as it could be helpful to others.

So the first picture is after I had undone the biggest bodge and put a ym2151 back in its place and a cpu.

This produced crisper audio, but no big changes, so on to the next, which is pulling off the audio z80 that looked like it had been overheated.

To my surprise after slotting it in, strider now had graphical glitches yet the audio was better.
The audio also was running faster so I have my hunches the toshiba z80 was purposely damaged to run correctly.
I will need a correct crystal for this board as the unlabeled one is likely 4 mhz, incorrect.

How interesting!

So now with china strider admittedly clearly broken by whatever they patched to make their bodge work in code, I tried an original b&c japan champion edition.

No issues. So they modified the code. It isn't the board.
Still fast audio.

This is where I break for now.

As I find out more, I will update this thread.
I have a ym3012 on the way and a correct stereo audio chip, as well as planning a full correct recap.

I will also need some resistors and the correct crystal.

If my hunches pay off, I think the bodge is fully reversible.
Time will tell.
 

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