Complex sentence: Its earliest products were the SQ306R, a 5MB 3.9 (100mm) cartridge disk drive and associated Q-Pak cartridge for IBM XT compatibles and military applications; subsequently a non-removable medium version was announced, the SQ306F.
Split into simpler sentences: Its earliest products were the SQ306R, a 5MB 3.9 (100mm) cartridge disk drive and associated Q-Pak cartridge for IBM XT compatibles and military applications. Subsequently a non-removable medium version was announced, the SQ306F.