On Sun, May 22, 2016 at 3:51 PM, John Robertson <j...@flippers.com> wrote: > On 05/21/2016 10:53 PM, David Collins wrote: >> >> Martin, I might be able to help you as I think we have a 7596A... >> >> I haven't looked at the plotter itself, but the service manual we have >> shows the following part numbers for the processor PCA >> >> 07595-18039 >> 07595-18040 >> 07595-18041 >> 07595-18042
After wrestling it out of a tight corner and pulling the side panel off and all the machine screws and nuts off the electronics housing, my 7596A had 2 EPROMs, marked (w/Intel logo): 1818-3825 S70137 According to http://www.cpu-world.com/forum/viewtopic.php?t=25006, they should be 27C512s. They are 28-pin parts with the same coloration and lettering as real Intel 27C512s. >> the EPROMs are labeled 07595-18045 and 07595-18046. The paper labels on mine have the part numbers: 07595-18095 07595-18096 Could you have read '4' instead of '9' perhaps, or perhaps mine are a different revision? My plotter has two DB25F connectors and one IEEE-488 connector. I'm not sure what other features (besides date of manufacture) might lead to different ROM revisions. > If your version has four EPROMs and the later (otherwise identical) machine > only used two then chances are the four earlier EPROMs were simply combined > into two later ones. For example, if the original EPROMs were 2708s then two > of those would fit into a single 2716. The 2716 was easier to program as > well being only a single voltage device. This device is far newer than those parts, but the principle is the same, of course. I should be able to read these out this week and share the contents. -ethan
