24 May
2016
24 May
'16
6:46 a.m.
On Sun, May 22, 2016 at 3:51 PM, John Robertson <jrr at 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