I've made five different backplanes, two are buffered and replicas of the original Acorn 8-Slot and 12-Slot Backplanes which I have, the 10-Slot unbuffered backplane is intended for a System 5 whilst the 14-Slot Backplane can be used for an even bigger System 5 or my combined FileStore/Econet Clock and Bridge.
These Backplanes are designed for mounting on a Card Frame with 'Connector Mounting' tie bars, here the connectors are soldered to the Backplane and then the connectors are attached to the tie bars. Card Frames can also be fitted with 'Backplane Mounting' tie bars and for these the Backplane PCB is wider and is fastened directly to the tie bars, I have a 14-Slot Wide Backplane for just this situation.
I haven't found an original Acorn schematic for the Backplane, there is a little information in the System 2 Technical Manual.
My 8-Slot Backplane is a good copy of the original Acorn 8-Slot Backplane, this was a single sided PCB and only tracked the Side A connections. I have also tracked side-B on the top side of the PCB. The 12-Slot Backplane is simply a stretched version of the 8-Slot.
The 10-Slot and 14-Slot Unbuffered Backplanes simply tracks both A and B sides across all 10-Slots, it is intended for systems which have a buffered Address Bus.
Schematics
Bill Of Materials
Blank Backplane 8-Slot Buffered
Blank Backplane 12-Slot Buffered
Blank Backplane 10-Slot Unbuffered
Blank Backplane 14-Slot Unbuffered
Photo to follow
Blank Backplane 14-Slot Unbuffered Wide
