Zaxxon "Object Ram"... where is it located on PCB?

alejandromad

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Zaxxon "Object Ram"... where is it located on PCB?

My Zaxxon is missing many objects (like the ship) or places the wrong objects randomly around the screen (like missiles or explosions). It also fails the self test as shown below.

I have looked through the schematics, the KLOV message boards and used Google but I cannot figured out where the "ORAM" is located on the PCB set.

The manual states: "The Work RAM Test is made for two Work RAMs (2K bytes each)."
Question... anyone know where this RAM is located?

Thanks!
 

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The manual states: "The Work RAM Test is made for two Work RAMs (2K bytes each)."
Question... anyone know where this RAM is located?

If I were to hazard a guess, I'd say it would be on the game's logic board somwhere.


But, guessing more closely, according to the manual, the only two 2 kilobyte RAMs I see are the ones at U37 and U38 on the A board. But, then again, that's only a guess.

And... further guessing, if it's a 24 pin chip, it's pobably a 6116 equivalent.

-Ian
 
Hmm. I'm reading the manual more closely. It would appear that you've pulled a line of text from another test and applied it to your ORAM problem. That bit about the 2K RAMs is talking about Work RAM, which is an earlier test.

ORAM test is listed with the VRAM test. Not sure what those are, but it's likely *not* the 2K rams mentioned earlier. There are some 2114's on the board (U70, 71, A board), as well as some 93422's (U42, U62, B board). 93422's are equivalent to 2101A's. Are any of these chips socketed?

Honestly, I don't know the Zaxxon board at all, all I have to go on is the manual.

-Ian
 
You know... you are absolutely correct. I guess I ended up back at the previous quote because of the final line (at step 5 "Video RAM and Object (Target) RAM Test") that says: "The check method is the same as described in step 2."

Sadly there is no indication of the size, type or location of this RAM.

I was looking at the Schematic portion trying to locate a reference to "Object" or "Target" RAM but haven't really seen anything.
 
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Hi!

Although the 93422's are the same size wise, they're much faster ( generally around 35ns ) and often used for line / object-ram. If they're socketed, try replacing those...

-Yvo
 
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