Converting Q*bert main board to Mad Planets?

GaryMcT

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I've read here that a Q*bert main board can be converted to Mad Planets board. Can someone describe the process? Is it a simple ROM swap? I've searched here and Google and haven't found the info.

Thanks!
Gary
 
Update on this. I did a rom swap a while bak and got Mad Planets booted one time. Still have a problem now since I keep getting rom errors, but I would guess that it *should* work since it did work once. Hoping to make some more progress on his soon.
 
I know I converted a friends Mad Planets board to QBert. It was ROMs and Ram. It was a long time ago, so I can't remember the details. I compared his Mad Planets board to a working QBert board......Installed new ROMs and installed/removed RAM (and possibly other chips) to match the QBert.

Edward
 
I know I converted a friends Mad Planets board to QBert. It was ROMs and Ram. It was a long time ago, so I can't remember the details. I compared his Mad Planets board to a working QBert board......Installed new ROMs and installed/removed RAM (and possibly other chips) to match the QBert.

Edward

Thanks! I did end up removing ram to convert to mad planets. Qbert needs more ram.

I'll likely reborn the chips I'm using to convert to mad planets as qbert and see of that works to verify that the chips are working okay in the board.
 
Update: I was over at Gary's this weekend and can report that the problem he was having was bad EPROM's. After burning a good set, he's now got a working Mad Planets board!
 
Yes! It's alive!

The process is to simply swap out CPU, foreground, and background roms. Mad Planets uses 5 CPU roms (Q*bert uses 3). Q*bert also requires more RAM chips than Mad Planets, but it's fine to leave the extra one in there.

I suspect my first attempt failed due to using ROM that is too slow. Ended up using 250 and/or 300 ns 2764's and all is good. Found good roms by:

1) putting a known good Q*bert rom set on the board.
2) erasing and burning a bunch of 2764's as CPU rom 0 for Q*bert.
3) replaced CPU rom 0 repeatedly and ran the test mode memory checksum.
4) kept ROMs that passed the checksum. Not all do, even ROMs that the rom burner thinks are fine. I suspect it's an issue with ROM speed.
5) erased and reburned all CPU roms on the newly found blanks as the 5-chip Mad Planets set.
6) Success!
 
Here's the Mad Planets which was converted from a Q*bert board running in a Q*bert cab. In the second video, I'm testing out a Mad Planets audio board that I bought from QuarterArcade.com a while back. Getting closer to getting my Mad Planets cab deconverted! Still need to convert a Q*bert harness that I bought to Mad Planets.



 
You nailed it - easy conversion.

Bill
 
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