MV4 question

I finally found 3 seconds together to start looking at my not-working 4 slot that I recently purchased, and had a few questions... I think I figured most of them out, but would prefer some confirmation.

http://img.photobucket.com/albums/v708/jlucero72/4b849141.jpg


At the top of the picture is a socketed chip that is coming out. Would just like to know what it is...

Under that are 2 empty sockets... supposed to be empty?

In the middle is the BIOS, yes?

To the right is the SMT chips that are used as work RAM? I really don't think the big square ones would be right since they are stamped SNK...

Which 2 are the Video RAM that give the 8000 error?

Anyway, thanks in advance for your help!

hmmmm.... picture was bigger than that... not sure what happened! Will try again later....


There we go... no idea why it did that before!!

Any help?

I put the UniBIOS in today and re-seated the other chip... I'll slap the board back together either tonight or tomorrow.

Almost have my MacGuyvered test rig done. Just need to make something to act as switches, and lengthen the video wires to reach from my bench to my Sky Shark monitor...

Sky Shark! Ah, the Romstar days

Anyhoo,. the fast sprit RAM are NOT flatpacked rams, but two 24 pin rams right under the M in "RAM?". The rom up above is the L0 rom, which is the sprite scaler.

The empty sockets were set to the sprite graphics table. Originally, they would contain mask roms with the Neo Geo logo. It was found to put the logo as a part of the cartirdge graphics, so the sockets were never used.

The ???? mask rom is the Fix rom, which translates as the text rom. When you look at text in the self test, it comes from there, along with the gfrid screen. When a cartr4idge is invoked, then it uses the fix rom inside the cartridge.

The 6 circled flatpack 256 RAMS are actually 3 banks of RAM wired seperately. They are the cpu work ram, the battery backed up ram, and the text/pallete 0 ram.

hope that helps in understanding it all. For more in understanding how the neo geo system worked without any background graphics whatsoever, check out its grand daddy game, a neat little game I got to name called Time Soldiers. (ok, so its a dumb name, but it worked

UncaJJ said:

Any help?

I put the UniBIOS in today and re-seated the other chip... I'll slap the board back together either tonight or tomorrow.

Almost have my MacGuyvered test rig done. Just need to make something to act as switches, and lengthen the video wires to reach from my bench to my Sky Shark monitor...

Click to expand...

Hi, I just wonder where you got that unibios chip from and what you paid for it?

Regards, Raz

Nightmare Tony said:

The empty sockets were set to the sprite graphics table. Originally, they would contain mask roms with the Neo Geo logo. It was found to put the logo as a part of the cartirdge graphics, so the sockets were never used.

Click to expand...

Wow, I never knew this. Am I right in thinking that only the 4 and 6 SLOTs have these enpty sockets or do other MVS's have them also?

Raz

Razoola said:

Hi, I just wonder where you got that unibios chip from and what you paid for it?

Regards, Raz

Click to expand...

Hi Raz,

I paid $5 shipped to a friend from another forum to burn it for me as I don't have a burner. I'm still MacGuyvering my test harness so I can connect it to my cab though.

-J

So, I also talked to NT in PM with the following:

Thanks Tony

What about the:

Video Ram Error
Address . . .Write . . Read
0000061B . 5555 . . 1555

-J



...it looks like a bad bit in the upper work ram. Its one of the flatpack rams. You will need to be able to change flatpacks and have a schematic to that part to trace to which of the 6 ram chips it is.

Toiny