The HP 4145A has four programmable stimulus/measurement units capable of high resolution plus wide range sourcing and sensing (1 pA to 100 mA; 1 mV to 100 V). Other features: built-in graphics analysis functions including marker and cursor which provides direct numeric readouts and a line function for automatic calculation of line gradient and X-Y axis intercept values. The HP 4145A also includes a built-in flexible disc drive for permanent storage of user programs and measurement results.