Re: Battlezone problem (Self test)

>> Has anyone ever disassembled BZ to figure out just what self test is
doing?
>> I have two boards (as I have said before) that when put into self test
>> appear to be starting self test then watchdog out and reset (at about the
>> time they should tone once and display data). But both boards run when
not
>> in test (though no display data).
>
>That is a strange one, it is usually the opposite. I have dissassembled
>the ST in
>battlezone once about a year ago. The reason I did it was because I was
>having some

> Sets up the Stack pointer
> Clears all the RAM
> Tests the RAM a chip at a time, a half byte at a time (since the
>2114's are one 4 bits wide)
> tests the ROM
> tests the pokeys
Pokeys on a BZ?

> tests the EAROM.

When you say EAROM what do you mean?

>LS245's. Well, it worked. That was the
>problem. Flaky 245's... Ugggh.

I wish it was just bad ram. :(

>Hope that rant helped some though?

Its a start. Where does the displayed test screen come from though? Is it
a small loop of code that runs the vector section or is there a "Ship" in
the vector rom that is the display that it just keeps running through? I
once had a board that only half the grid was displaying when I got the board
fixed I was told it was a bad cap but they didn't say which one. So I am
wondering if some of the test screen is literaly hard wired or is it all
just normal display functions.

David
Received on Thu Jan 15 23:49:14 1998