In my pursuit of IBM Displaywriter hardware I spied these boards on eBay:
http://www.ebay.com.au/itm/111224097497
Compared with these boards there are some similarities regarding the edge
connector and overall shape/size:
http://bitsavers.trailing-edge.com/pdf/ibm/6580_Displaywriter/photos/
but of course these boards were used in many other IBM peripherals and
small systems from that era.
Does anyone recognise what they might be from?
There are three boards for the IBM Displaywriter I am seeking to find:
Memory Extender Card (fits into Slot F)
Printer Sharing or 3277 DE Card (for Slot C) - not sure if same or
different boards
Communications Card (slot A)
There may also be another board that fits into the external floppy drive
unit to support the additional communication ports that were available on
the back of that unit.