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So, I posted here about a year ago about a 128k Macintosh that I got off of craigslist. Since then I figured out that the ram was bad and replaced it. I've got to a point where the computer functions but the video has a major issue. I have been unable to find the issue so far, so here I am again! For further reference, I do have logic probes and an oscilloscope at hand if that helps fix the issue.

(Before Ram Replace)

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(After Ram Fix)

IMG_1184.thumb.JPG.ef1e1514a49b27c10216d86e77f6c359.JPG

IMG_1185.thumb.JPG.5d13757712600e545fedafedbd8d4e1b.JPG

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Where is your arrow pointer? When you move it around the screen, does it also show up more than once? Do you have two arrow pointers moving simultaneously?

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Could this be caused by a bad mux or demux (assuming the 128K has anything like that) causing the same data to be stored multiple times to the framebuffer?

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Probably not, I already replaced the MUX chips with brand new Motorola chips but this next chance I get I'll test them with my logic probe to see if I scorched the chips while soldering.

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