The IONCAP (Ionospheric Communications Analysis and Prediction) program is now available for the IBM Personal Computer AT™. The computer resources required to run this program are 512 Kbytes of memory with a hard disk or high-density floppy disk. A math coprocessor, while not necessary, makes the execution time more reasonable. The program resides on disk as a single run module and does not require overlays. It is possible to run the IONCAP program on an IBM PC XT™. However, the XT must have a hard disk and the program must be linked on the XT, because the floppy disk on this model does not have sufficient storage capacity to hold the run module.