the com files are raw binary executables and are a leftover from the old cp/m machines with 64k ram. a com program can only have a size of less than one segment (64k), including code and static data since no fixups for segment relocation or anything else is included. one method to check for a com file is to check if the first byte in the file could be a valid jump or call opcode, but this is a very weak test since a com file is not required to start with a jump or a call. in principle, a com file is just loaded at offset 100h in the segment and then executed.
offset count type description 0000h 1 byte id=0e9h id=0ebh those are not safe ways to determine wether a file is a com file or not, but most com files start with a jump. further information not available. extension:com occurences:pc see also:exe,mz exe,ne exe