A copy of the data within the SFILE and subdirectory SUBDIR is created in a disk archive file MYFILE. This file can be copied to a tape with the UNIX tar command. The file has the same format as the telescope, one can add this disk archive file to the program as a second argument when starting up SPA. From then on, the disk archive when in the T file subdirectory. It is a READONLY subdirectory. When running the dar program, one is prompted within the script for the three arguments if not present on the command line. If the disk file does not already exist, then an error message is printed and the program prompts the user for the size of the disk archive file in units of 5120 byte blocks. For single pixel data, each scan is one block (1024 bytes of header + 4096 bytes of data). For multipixel, the number of blocks/scan depends on the number of pixels/scan (16 or 32) and the number and type of backends within the scan. All multi pixel scans have a 4096 byte header. The estimation for the number is more complicated since the data for an individual pixel can not cross a 4096 byte boundary. For an observed configuration of Q23 and Q15 with 32 pixel scans, the number of data blocks is 2 so the total number of blocks/scan is 3. For an observed configuration of Q23, Q15, and QEF with 32 pixel scans, the number of data blocks is 4 so the total number of blocks/scan is 5.