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Multi Boyz Litigator
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Well, good to know for the future :)

Programmed the GAL and Espgaluda's been up and running for about half an hour now. Took a run through the first two stages, and it's been on attract ever since without issue.

Bunch of stuff to do today and get caught up with for other folks, so I'm not sure if I'll get to Ketsui today too, but hopefully!!
 

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Espgaluda runs perfectly with the new gal.

Ketsui now doesn't crash with the new gal (but I can't select Trap mode, right?). But the audio is super distorted. Put back the old gal and I've realized that audio is distorted only in normal Ketsui, but perfect in Trap mode. So one step forward, and one step back?
 

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Yes, the new GAL removes the input for the jumper. What I guess is happening is that the input is not correctly pulled up, and the game randomly switches between the top and bottom half of the EPROM. For Espgaluda it crashes as soon as it happens, as the second half is just $FFFF, for Ketsui it crashes as soon as there is a difference between Normal and Trap. If you have a scope you could trace the highest address line for noise.

I double checked the data sheet, and it doesn't look like the pull up is a programmable option that could be different depending on which programmer you use. You could verify the voltage across the GAL, in case it drops too much as system load increases. Though I expect you've got a better power supply than me, and voltage drops would probably cause bigger problems. I don't think it is a GAL quality or "fake chip" problem either if you bought from Digikey.

If you want the jumper to work you could try the pull-up resistor mentioned above. Otherwise, does anyone who has done this for longer have any idea? If the external pull up resistors work I can integrate them into the layout, so people can populate them if necessary.

The Trap version of Ketsui uses exactly the same sound EPROMs, and the bus configuration doesn't change. I assume you tried cleaning contacts, wiggle the cartridge?
 

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The Trap version of Ketsui uses exactly the same sound EPROMs, and the bus configuration doesn't change. I assume you tried cleaning contacts, wiggle the cartridge?
I think it was an insertion issue. Like I just happened to reinsert it wrong only when on normal Ketsui a few times in a row last night but perfectly for each Trap attempt. Today I booted it up in trap, then swapped the jumper over without removing the PCB and everything works fine sound-wise. Still crashes of course. Ha.


To understand fully regarding the resistor: if I put the pull-up resistor on while using the new GAL it should force it into trap instead of standard? And at that point I'd have to use the resistor to swap back and forth?
 

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No, the new GAL is hardcoded to use the lower half of the EPROM:
Code:
PA20_I = PA20;
PA21_I = 'b'0; <===
If you changed that to
Code:
PA21_I = 'b'1; <===
and made a new GAL it would force the upper half.

To make the jumper work you need the original GAL. If the resistor fixes the problem you can use the jumper (or a small switch) to switch between versions.
To test, you need to open the jumper, and connect pin 1 of the jumper (the one that is NOT connected to ground) or pin 8 of the GAL with a pull-up resistor to +5V.
 

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To make the jumper work you need the original GAL. If the resistor fixes the problem you can use the jumper (or a small switch) to switch between versions.
Got it. Original gal, add resistor, hopefully everything works as expected originally.

I will give it a shot in a little bit here.

Thank you for all your help getting these up and running. Not sure why I'm having issues where others aren't, but I'm glad there seems to be a light at the end of the tunnel!!
 

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Basically what you want to achieve is this:

(https://learn.sparkfun.com/tutorials/pull-up-resistors/all if the link fails.)
 

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Would a modified plexi work? Has somebody tried it and also has laser cut files for modified plexi? thx
 
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