More 11/44 basic newbie help request

From: Kevin Handy <kth_at_srv.net>
Date: Tue Feb 11 10:02:00 2003

Jay West wrote:

>Eric wrote...
>
>
>>Get the manuals from Al's site.
>>
>>
>
>You know... I think I've just been told "RTFM" *grin*
>S'ok, was well deserved :)
>
>After perusing the manuals for the 11/44 and the RL02's, and the RL11
>(looking for docs on the 8 port mux now).... Most of my questions are
>answered there (big suprise). Not trying to start any holy wars or anything,
>but to my "newbie with unibus" mind, the design of having to change
>backplane wiring for certain cards seems to be rather... ummmm silly
>(euphamism{tm}), at least as compared to other systems of the period.
>Probably there is something I'm missing as to why this is a good thing.
>There are a few areas that I'm not quite sure I get what the manual is
>saying though, perhaps others can clarify WRT card positioning &
>requirements.
>
>Regarding the unibus terminator card...M9302 - everyone says "the last slot
>of the unibus". Does this mean physically the last slot in the backplane, or
>"logically the last slot of the unibus" meaning after the last card? I'm
>guessing the former, because it sounds like the last slot of the backplane
>has different wiring, and hence the need for lots-o-grant-cards.
>
>The manual states that for each open SPC slot, you have to use a grant card.
>But it's a little unclear as to "SPC" slot. In the "main" backplane, there
>is a hex SPC slot and a quad? SPC slot after the memory, the AB spots on the
>2nd SPC slot being for the 9202 jumper card. This gives rise to a few
>questions: If the last 2 slots in the "main" backplane are for SPC, are the
>remaining slots (in the 2nd backplane, AFTER the 9202 jumper) SPC slots? I
>assume you need a grant card in the hex SPC slot if nothing is there. But
>what about the quad SPC slot that also has the 9202 in it - does that slot
>need a grant card too? And about the 1st slot in the 2nd backplane that has
>the other side of the 9202 in it - that needs a grant card as well? I'm
>assuming it does...
>
>So in the example where you have no cards at all in the 2nd backplane except
>the initial 9202 and the final 9302 at the other end.. you must have a grant
>in every one of those open slots? If so, ummm I need a bunch of grant cards!
>Anyone have some to trade?
>
I believe that the backplane has the grant jumpered, and you have to remove
this wire if you want to put a card that uses that signal. That means
you don't
have to fill your backplane with grant cards if you have the jumpers
still on.

>
>I think that's the main questions - the rest makes pretty good sense and is
>fairly clear in the manual. Thanks a bunch!
Received on Tue Feb 11 2003 - 10:02:00 GMT