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Build your own PDP 8I, Part 2..

"The M16 is the IC designation from the Externally Sorted List, and the A10 Refers to the Internally Sorted List.."

In your travels through the documentation. did you see any explanation for why the wiring list was presented twice, once "Externally Sorted" and once "Externally Sorted"? Externally and Internally with respect to what?
 
Hi All;

""
In your travels through the documentation. did you see any explanation for why the wiring list was presented twice, once "Externally Sorted" and once "Externally Sorted"? Externally and Internally with respect to what? ""
"" once "Externally Sorted" and once "Externally Sorted"? "" I think You, meant once Externally Sorted and once Internally Sorted..
Anyway, I have no Idea, That and so many other Questions, we just don't know the Answer to.. And can only guess at..
My only guess is that one was earlier than the other, or they originally laid out the unit differently then the later unit.. Also, the Book mentions (I think) five other versions, before the book, so this would have been version number four, and (I think) they were encouraged to try different things and try different circuits out, looking for other/better ways of doing things..
Possibly reading the Lab manual, the Memory Paper and the I/O paper might help, and reading through both books.. But, I doubt it..
Also, remember that they got their Lab unit and most likely worked thru all of the Experiments on that Board, Wiring and un-wiring after each session.. Then, at the end of the School Year they took it home.. A fully (hopefully) functional PDP 8i clone..
I don't know this for sure, that they took it home, But, how else would Mark Arnold have been able to keep His Machine..
Here is a photo of today's progress..

001.jpg

THANK YOU Marty
 
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"I think You, meant once Externally Sorted and once Internally Sorted"

Yep.... I was being called to dinner & typing faster than my brain could keep up with. ;-)

I'm going to throw a wild guess out there. Perhaps they started using some sort of CAD software that wanted to rename the IC's after they had already been working on the row & column system. That would give you one name used internally to the CAD program and another name used externally. It's really far out there but I can think of no other context with respect to the rest of what I've seen in the posted material that would answer "Internal and External with respect to what?".
 
Hi All;

I have started to wire up LD-8, I cannot wire up LD-9, until I get the 18 pin sockets, for the 16 pin Ic's, and a Cap..
But, its a start..
The sockets should be here about Monday..

THANK YOU Marty
 
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