WRITEL is a program for writing labeled tapes on the DECSYSTEM-20, written by Charles Hedrick of Rutgers University in "Rutgers Pascal". It is used rather than the TOPS-20 Exec COPY command for making KERMIT ANSI labeled tapes because the Exec does not know how to store multiple records in one block and therefore wastes so much tape that only a small fraction of the KERMIT distribution would fit on a 2400 foot reel. WRITEL is one of a suite of useful tape reading/writing programs. Much of the intelligence is in the Rutgers Pascal runtime library (PASUNS.REL), which has extensive labeled tape support. Rutgers Pascal may be ordered from the following address: Marge Thompson CCIS Rutgers University Hill Center P.O. Box 879, Piscataway, NJ 08854 (USA) Here is the documentation for WRITEL: WRITEL Writes labeled tapes. Asks the following: Tape Name: The name of the tape, with colon after it. The tape has already been mounted and recognized as a labeled tape. Format One of: D, F, S, or U: F - fixed size records. All lines are filled with blanks to make them the same size. This format is the most likely to be supported by other computers, but wastes space if lines are of different lengths. If all lines are the same length, this is the best. D - variable size records. Lines are not filled. Special control information is used to show how long each line is. This is more efficient if lines of different lengths. However IBM systems can't read this format. S - spanned records. A slight variant of format D, for files with extremely long lines. Allows lines to be split across physical record boundaries. This is more efficient for very long lines, but takes a bit more processing overhead, and is supported by few other computer systems. U - undefined. Puts each line in a separate physical record. This is unlikely to be supported by other computer systems, and also wastes space, unless the lines are very big. Generally we recommend format F if lines are nearly the same length or if you need to be able to move the tape to the most possible different computers. Format D would be used for files with lines of very different lengths, if you are mostly concerned with DEC computers. Record size: This is the size of the longest line in the file. For format F, all lines will be filled to this length with blanks. For other formats, it should be a number that is known to be larger than the largest line in the file. (The exact value doesn't matter much.) Block Size: This may or may not be asked, depending upon the format. The block size is the size of the physical records on tape. More than one line (logical record) may be packed into one physical record. The advantage of packing into large records is the there is a .5 inches of space wasted on the tape for each record. So if you put many lines in one record, you waste less space for a given file. The maximum block size is 32768. For 1600 bpi tapes, a block size around 6000 is helpful. For 6250 bpi tapes, something near the maximum is probably a good idea. - For format F, the actual question is "how many records per block". The block size in this case is the record size times the number of records per block. - For format D and S, you are asked to specify the block size directly. - For format U, this question is not applicable. Copy From: This is the name of the disk file to copy to the tape. You may use wildcards. The program will keep asking this question. ^C when you have written all the data you want to write. See ANSITAPE.DOC for information about the format of ANSI labeled tapes.