2 layers100 × 86 mm

InterfaceBoard
farlepet/keithley-615-printer-boards
Drop-in replacements for the buffer/printer boards for the Keithley 615 Electrometer
184 partsMIT
Boards in 2 GitHub repositories, designed in KiCad, that use the BC856W by Jiangsu Changjing Electronics Technology (CJ) (-55℃~+150℃ 1 PNP 100MHz 100mA 125 150mW 15nA 5V 650mV 65V PNP SOT-323 Bipolar (BJT) ROHS). See how each wires it, with its parts, size, README and files; the BC856W’s symbol, footprint and pinout are on its own page.

farlepet/keithley-615-printer-boards
Drop-in replacements for the buffer/printer boards for the Keithley 615 Electrometer

drewsum/VFD_Clock
A VFD clock centered around a PIC32MZ EF microcontroller