The operating condition of the board is unknown - I picked them up at the 2002 Dayton Hamvention from a box of random printed circuit boards.
Left-hand component side of long board.
Right-hand component side of long board. Note the single trace on the bus connector.
Second board containing a Z-80 CPU. Note that there is no bus connector, just a horizontal ribbon connector.
Update: I received the following e-mail:
I was the production manager/electronics technician for sequential systems in the late 80's early 90's. The boards you have are the brains of a system called the Q system. It is a device that allowed you to hook up 4 apple 2e computers to one printer. It would take the print jobs from any of the 4 computers put the job in memory and take over the printing duties to free up the users computer. This was design specifically for the education market. The large board with the z-80 processor plugged in is for parallel printers, the large board with the smaller board that docks on it is for the apple imagewriter printers or a similar serial printer. The system also required a sequential systems or compatable printer card to reside in each of the four computers. These then hooked up to the Q-card via ribbon cables. The q-system would reside in one of the 4 computers. It was very cool running across this, I haven't thought of the q-system for years. It was my first electronics job out of college.