Tektronix DM44
Digital Multimeter Oscilloscope Option, Refurbished 
3.5 Digit LED Readout 
1 % Timing Measurements 
Resistance: 0-20 Megaohms 
DC Volts: 0-1200 Volts 
 
  
Increased measurement capabilities can be achieved with the optional DM44.

The digital multimeter and oscilloscope combine to provide a digital readout
of time difference between any two points on the oscilloscope display.

Both time measurement points are displayed simultaneously on the CRT.
Direct measurement of frequency is provided by 1/time function.