DPE is used to display measurement series.The program, which is fully integrated into GEM, allows various display modes, logarithmic scale, automatic scaling, range selection by mouse, regression (Lin, Pot, Exp, Log), display of error bars, as well as the additional display of a function f(x). The editor is used for manual input of the measured values, respectively for changing the imported data, which is especially comfortable due to the block functions (Cut, Copy, Paste). DPE supports the import of measured values via measuring instruments connected to the serial interface (RS 232) and is therefore well equipped for use in laboratories of all kinds. Of course, data can also be entered manually or read from an ASCII file...A calculator with the functions "LN, SIN, COS, TAN, COT, SQR, EXP, INT, ABS, FAK, SGN, DEG, RAD, RND,..." and the constants "PI, NA, k, Vm, e, me, u, h, G" is also helpful. GDOS is necessary for this.