This is a 4 layer PCB with double sided edge connectors at the front and rear. The top is populated with various DIP integrated circuits. There are 2 white jumper wires on the bottom
Date
1973
Manufacturer
Hewlett-Packard Company (HP)
Identifying Numbers
Other number
6-73
Stamped in front corner on top of board
Other number
A6
Stamped on left card extractor
Other number
B-1238-22
Version etched/stamped in front corner on top of board