This protoboard follows the basic Mark-8 layout of wired bus and 0.156" connectors around the edges, and a field of 0.1" x 0.3" holes interleaved with power buses.
Since the bus is traditionally hardwired between the boards, it is very difficult to work on the protoboard after it is installed. The best solution is to install connectors on all the boards (as the layout of the boards suggests might have been intended). For the purposes of the protoboard, I came up with a simple solution that's not too ugly. If one cuts along the line of holes around the bus area, this part can be be soldered in to the Mark-8 bus and the bulk of the protoboard removed. Short 16-pin DIP-to-DIP cables with a 90 degree flip are used to connect the bus part with the main part.
Eagle CAD file