Tektronix introduced a family of modular test and measurement products called the TM-500 series.  The main frames were available in one to six slots and there were probably over 100 plug-ins available over the years.  The main frames had a flexible power supply configuration to support the plug-ins.

The museum has a pair of four wide TM-500 main frames on display.  The top main frame has the SC501 oscilloscope, the FG502 function generator, the DM501 digital multi-meter, and the PS503A dual tracking power supply. The bottom main frame has the AM503 current probe amplifier, the PG501 pulse generator, and the SC502 oscilloscope.  These types of general purpose setups were used widely in engineering, manufacturing, and service operations.

The TM-5000 series replaced the TM-500 series which added GPIB capability to control intelligent plug-ins.