>Thanks Megan!
Any time... glad to help...
>It turned out that when I removed the Viking tape card to inspect it I
>re-inserted it backward (no ears on that one). That meant the RQ11
>wouldn't fit in slot 6 and that meant an empty slot.
Whoops... I've done that once before (*once*)
>Q1) So how badly does it toast things in the Q-bus to be backwards in
>slots A-B ?
>Q2) Do all empty slots need to have bus grant boards?
Let me answer like this...
In a BA123:
o The Qbus passes direct from slot1/ab to slot4/ab
o For slots 5-12, it does the serpentine (4/cd, 5/cd,
5/ab, 6/ab, 6/cd, etc)
o All dual boards must be placed at some point in the
serpentine. For slots 1-4, this means AB. For
slots 5-12, this can be either AB or CD.
o Quad boards which are not for CD, must go in slots
5-12
o For quad boards which can be either CD or Q/CD, the
jumpers on-board must be set for the slot you are
placing it in (there should be a couple of jumpers
which are removed if the board is placed in a Q/CD
slot, and installed if it is placed in a Q/Q slot)
o For quad boards which can only go in Q/Q, they may
only be placed in slots 5-12.
o If you follow the serpentine, there should be no
empty Qbus slots between the processor and the last
board in the bus (there are exceptions, but for now
regard it as a hard and fast rule).
o For any gaps in the serpentine, you should install
a M9047
That's it in a nutshell. For a BA23, the critical numbers are
slots 1-3 == Q/CD, 4-8 == Q/Q
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
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Received on Mon Mar 08 1999 - 22:25:04 GMT