IBM 4300

The IBM 4300 series[1][2][3][4][5] are mid-range systems compatible with System/370[2] that were sold from 1979 through 1992.

They had a disruptive effect on the market, allowing customers to provide internal IBM computing services at a cost point lower than commercial time-sharing services.

[2] It came with an integrated adapter that permitted attaching up to 16 of two newly introduced direct-access storage devices (DASD): The 4331 was withdrawn on 18 November 1981.

[3] Like the 4331, it came with an integrated adapter that permitted attaching up to 16 of the newly introduced IBM 3370 DASD.

Model Group 12 included the Dual Address Space (DAS) facility.

Model Groups 1 and 2 were announced Sep 15, 1983 and withdrawn on 11 February 1986.