TPMISS by David Rogosa and Ghassan Ghandour
The DOS utility tpmiss.exe takes as input a longitudinal data set with the rectangular structure shown in Exhibit 1 (p.153) (such as is produced by tpsim) and overwrites a designated proportion of the observations with a missing data code.
The program requests

A similar utility tpmissmr.exe can be used for creating missing observations for longitudinal data structures (such as the data in the Reply) where each individual has different observation times. The requested input are the two data files, the first containing the Y-observations and the second the individual times of observations, such as those that are concatenated in yfzfsm.dat. That program provides for writing output files in both rectangular formats ("TP") and in separate vector formats ("Mathematica").