MV1B MVS - ILLEGAL INSTRUCTION 200000C0 (Unibios 3.2)

Spicules

n00b
Joined
Jul 20, 2012
Posts
21
So I installed a biosmasta and replaced my battery, and faulty backup ram chips on my m1vb.

Things were working great for a bout a week or so.

Now, I get this error!

UGH!

Anybody know what this could be?
 

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Razoola

Divine Hand of the UniBIOS,
Staff member
20 Year Member
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Nov 12, 2002
Posts
4,662
When does this error happen? What unibios do you have?
 

Spicules

n00b
Joined
Jul 20, 2012
Posts
21
Unibios 3.2

It was playing metal slug X on a 161-1 - it was just playing in demo mode. Then crashed to that error. TUrned it off, back on again - same error.

I inspected the board, and the lead from my biosmasta looked a little off - like maybe it broke off. I resoldered, and put back in. Then, no pic, no audio. Looks sorta like watchdog - there's a little flicker of a couple pixels when it does it. (No clicking - I have the audio hooked up to a stereo amp only)

Plugged in a diagonstic bios rom, and got the following error:

WRAM ADDRESS A0 - A7

ADDRESS: 100028

ACTUAL: 14D4

EXPECTED: 1414
 

Razoola

Divine Hand of the UniBIOS,
Staff member
20 Year Member
Joined
Nov 12, 2002
Posts
4,662
Do you have any original games you can try?
 

Spicules

n00b
Joined
Jul 20, 2012
Posts
21
Yes - it does this with my Metal Slug X MVS cart, and the 161.

I have an a MV1C board, and both games work fine on there.

I ordered more rams for the work rams; going to replace those and see if there's any change.
 

Razoola

Divine Hand of the UniBIOS,
Staff member
20 Year Member
Joined
Nov 12, 2002
Posts
4,662
have you tried removing the biosmasta, cleaning up the 68k cpu and reseating it?
 

GadgetUK

Ace Ghost Pilot
Joined
Sep 27, 2013
Posts
1,323
Yes - it does this with my Metal Slug X MVS cart, and the 161.

I have an a MV1C board, and both games work fine on there.

I ordered more rams for the work rams; going to replace those and see if there's any change.

Make sure you've enabled HW test in the unbios, because if it is WRAM the unbios should detect that on boot.
 
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