Difference between revisions of "H9273 backplane"
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It was a [[QBUS#Variable_address_size|Q18]] backplane, but it is relatively easy to [[upgrading QBUS backplanes|upgrade it to Q22]]. | It was a [[QBUS#Variable_address_size|Q18]] backplane, but it is relatively easy to [[upgrading QBUS backplanes|upgrade it to Q22]]. | ||
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Since it was a Q/[[CD interconnect|CD]] backplane, dual-width [[QBUS]] cards could only be placed in the left-hand slots, and quad QBUS-only cards had to not use any pins on the [[DEC edge connector contact identification|right-hand C/D connectors]]. (The only DEC card with a problem with this seems to have been the [[MMV11-A QBUS core memory|MMV11-A]].) | Since it was a Q/[[CD interconnect|CD]] backplane, dual-width [[QBUS]] cards could only be placed in the left-hand slots, and quad QBUS-only cards had to not use any pins on the [[DEC edge connector contact identification|right-hand C/D connectors]]. (The only DEC card with a problem with this seems to have been the [[MMV11-A QBUS core memory|MMV11-A]].) | ||
Revision as of 11:55, 5 July 2022
The H9273 backplane is a 9-slot Q/CD QBUS backplane, the standard backplane in the BA11-N mounting box. It could hold quad-sized cards.
It was a Q18 backplane, but it is relatively easy to upgrade it to Q22.
Since it was a Q/CD backplane, dual-width QBUS cards could only be placed in the left-hand slots, and quad QBUS-only cards had to not use any pins on the right-hand C/D connectors. (The only DEC card with a problem with this seems to have been the MMV11-A.)
External links
- BA11-N mounting box user's guide (EK-BA11N-UG-001) - the H9273 is covered on pp. 10-13
- PDP11/23 Field Maintenance Print Set (MP00740) - The H9273 is covered in the BA11-N Field Maintenance Print Set (MP00487) on pp. 41-51
