Troubleshooting

[phaxda]

This one I just cannot figure out. My guess was the cart slot, but I have cleaned it thoroughly. What else could produce this garbled kind of output?

 

 

Sucks because it is a nice system otherwise.

[zylon]

Try replacing/swapping out the chip closest to the cart port. Then the center chip if that doesn't clear it up.

[A.J. Franzman]

Try replacing/swapping out the chip closest to the cart port. Then the center chip if that doesn't clear it up.

My guess would be somewhat the opposite -- start with the chip farthest from the cart port (TIA, #CO10444), then if swapping that doesn't fix the glitch, try the one closest to the cart port (RIOT, 6532, #CO10750), and leave the middle one until last (CPU, 6507, #CO10745). All of this is assuming that it's a 2600 console, not a 7800. I don't know what a 7800 looks like inside, but it uses the same chips for its 2600 compatibility mode (some of them may have different numbers).

Edited March 29, 2010 by A.J. Franzman

[tetrode kink]

Is the Juno First title marquee rendering correctly?

 

If yes, I'd suspect the cart; part of the ROM is corrupted. The marquee uses the same sprites the rest of the screen uses, so if it were the TIA, why would it render some sprites fine and others not?

 

If no, probably one of the above answers.

 

I'm asking because your photo captured only half of the title, it flickers alternate lines (Andrew Davie's ColourClock™ routine?) to render a mask wider than 48 bits.

 

Turn off the room lights, then either turn down the brightness on the TV or close down the shutter setting on the camera so it takes a longer time exposure of the screen.

 

-tet

Edited March 29, 2010 by tetrode kink