Pole Position graphics issue

edshootemup

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Hello All,

I have a pole position upright where everything plays fine except the cars and signs in the distance are appearing as blocks. When they get near they are no longer blocks however. Any help in the right direction would be greatly appreciated in fixing this.

Thank you,

Ed
 
Sounds like an EPROM issue, someone here can burn you new ones no problem.
 
I had this exact issue. I cleaned and reseated all socketed chips on the video board. Before you do that, make sure your voltages are correct, bulletproof it, and make sure the interconnect board is properly snug on both the CPU and video boards. I did all that, and it cleared my block problem
 
I agree, do the +5v and ground mod and clean the eproms. Once you do those 2 things, if there are any issues, then you actually have problems.... the +5v mod and Eprom cleaning have solved almost all of my pole position problems.... also make sure your AR2s are good.
 
Don't even need to do them all, just run from the +5 pin and Gnd pin to one test point each. And yeah, double check the inter connect cable. Press down on all socketed chips, and see if it clears up.
 
It might be one of the eproms at 12N or 13N Check that first.
if those are okay you will have to debug the circuit, starting with 10B and kind of work your way around the hardware scaling circuit which is integrated with the sprite decoder on pages 13B 14A 14B of the schematic.
 
It might be one of the eproms at 12N or 13N Check that first.
if those are okay you will have to debug the circuit, starting with 10B and kind of work your way around the hardware scaling circuit which is integrated with the sprite decoder on pages 13B 14A 14B of the schematic.

Yep, I agree. The manual tells you that "small cars & signs" are the eproms at 12N and/or 13N on the video board. The fact that nothing else seems to be a problem makes the eproms a good place to start.
 
Thank you ! I will look at 12N and 13N. Other than physical appearance, how can I test ?

You would need an eprom reader to test them properly. It reads the code that's on the chip, saves that to your computer, and then you can compare that file to a known good one to make sure it is all correct. Assuming you do not have one of these, you might ask around and see if anybody in your area can help.

I would start by re-seating those two ics as TheEnglishTear suggested. The video below shows that, although I don't like using sandpaper as this guy suggests, I prefer a pencil eraser.

https://www.youtube.com/watch?v=RkSCh53fO6Y
 
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