Irem UNDERCOVER COPS Graphic issue [ HELP ]

Hmm…this one is a bit of a head-scratcher.

Since the palette is still messed up when transferring the original ROMs to a known-good B board, it definitely sounds like a bad Sprite ROM. Perhaps the replacement EPROMs you tried are too slow? Make sure you’re using 27C080 EPROMs for the Sprites that are 120ns or faster.

Do dumps of the original Sprite ROMs match the MAME checksums?

Also make sure that your power supply is delivering 5.0V to the board set. These are power hungry boards and it’s possible that your Undercover Cops ROMs need more juice.
 
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Wasn't there something wrong with the chip order? I remember i did a upgrade to the Alpha renewal, and the chips were in reverse, or something. I.e. mame source was wrong if i recall. Its been 10+ years, i don't remember exactly.

Ding ding ding, we have a winner!

The roms were in reverse order. Funny that it results in sprites that almost look correct.

Correct rom order is

LH538K16 goes to C39 (000)
LH538K17 goes to C40 (010)
LH538K18 goes to C41 (020)
LH538K19 goes to C42 (030)
 

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Ding ding ding, we have a winner!

The roms were in reverse order. Funny that it results in sprites that almost look correct.

Correct rom order is

LH538K16 goes to C39 (000)
LH538K17 goes to C40 (010)
LH538K18 goes to C41 (020)
LH538K19 goes to C42 (030)
Nice, good thing i have my mind to trust on :)

Did you get the board with reversed chips in place? That's the one thing i don't understand at this point.
 
Quite right.

That was on me :whistling:

Due to work I have a lot of downtime that I can spend on the computer, and I have a habit of dumping all the arcade gear that I get. Everything that's socketed gets done, regardless of how common it is.

When I got the board I couldn't test it right away since it didn't come with the motherboard. So I first dumped the board, then only afterwards tested it. Some time had passed in between and I kind of spaced out on it.

Plus, Mame documentation does indeed show different rom locations to what's on the board, so I did the order by memory, and my memory is shit.
 
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