Graphics issue any ideas?

[heatw]

 

the graphics all work, how ever there is two of everything displayed any ideas, this is the old black and white taito space invaders cocktail table.

 

it's like it's drawn once i nthe right place then again 2 rows down

[DanBoris]

Could be a stuck address line going to the video memory. That would cause certain blocks of memory to be repeated because the state of the address line wouldn't change when it's supposed to.

 

Dan

 

the graphics all work, how ever there is two of everything displayed any ideas, this is the old black and white taito space invaders cocktail table.

 

it's like it's drawn once i nthe right place then again 2 rows down

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Edited December 26, 2005 by DanBoris

[heatw]

hmm alright, i've never really dealt with these older games, mostly used to neo geo.. and newr games...so o you know exactly where i would look to check this problem and what i would be doing to resolve it?

 

Could be a stuck address line going to the video memory. That would cause certain blocks of memory to be repeated because the state of the address line wouldn't change when it's supposed to.

 

Dan

[bjk7382]

I would first clean the edge connector and the pins on the 2 other connectors, and see if that fixes it. (you want to start with clean connections all around before you start digging into the PCB)

 

I would also suggest gettting the Braze Multikit, it has a Diagnostics test that lets you know of ram errors and other things.

[heatw]

hmm thatnks, i never considered the connector because it looks liek it hasn't been removed in 20 years haha but that would be a whole lot easier to fix!

 

hmm i'd seen that before but becasue it says for MIDWAY space invaders, i assumed it didn't work with mine, since i didn't see midway printed anywhere on it i assumed it was pre midway.. it only has taito lables

 

I would first clean the edge connector and the pins on the 2 other connectors, and see if that fixes it. (you want to start with clean connections all around before you start digging into the PCB)

 

I would also suggest gettting the Braze Multikit, it has a Diagnostics test that lets you know of ram errors and other things.

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