Complex sentence: The Annex was capable of serving one parallel printer and up to 16 serial printers, terminals, modems, or serial consoles to various equipment and later models supported more serial lines; making it the first OOB management server.
Split into simpler sentences: The Annex was capable of serving one parallel printer and up to 16 serial printers, terminals, modems, or serial consoles to various equipment. Later models supported more serial lines, making it the first OOB management server.