historia de los sistemas de base de datos By edward ceballos Period: Apr 7, 1928 to Apr 8, 1949 tarjetas perforadoras (Herman Hollerith) Period: Apr 7, 1929 to Apr 8, 1980 Tarjetas perforadoras Period: Apr 7, 1950 to Apr 8, 1980 cintas magneticos Period: Apr 7, 1970 to Apr 8, 1980 discos fijos