I designed a extender card for the Vectrex cartridge slot with pins to break out the signals. I have attached two files. The first, Extender.zip, is the schematic and board layout created in DipTrace, a free (as in beer) PCB CAD program. The second, ExtenderGerbers.zip, is the Gerber files generated by DipTrace that you can send to a PCB manufacturer to have the boards made.
- Bob