IBM mainframes

Following are the mainframe architectures used in IBM mainframes since the original System/360 introduced in 1964.

 Year Architecture  Model numbers

 System/360
 1964 System/360     2xxx (2020 to 2195)

 System/370
 1970 System/370     3xxx (3115 to 3168)
 1977 System/370     303x (3031, 3032, 3033)
 1979 System/370     43xx series
 1980 System/370     308x series (3081, 3083, 3084)
 1981 XA/370         308x series (3081, 3083, 3084)
 1986 XA/370         3090 series (120 to 600)
 1986 XA/370         9370 series
 1988 ESA/370        ES/3090 and ES/4381

 System/390
 1990 ESA/390        ES/9000, 120 to 9X2
 1994 ESA/390        9672 Exx & Pxx, G1
                       Parallel Transaction Server
 1994 ESA/390        9672 Rx1, G1
                       Parallel Enterprise Server
 1995 ESA/390        9672 Rx2,Rx3, G2
 1996 ESA/390        Multiprise 2000 (2003-xxx)
 1996 ESA/390        9672 Rx4, G3
 1997 ESA/390        9672 Rx5, G4
 1998 ESA/390        9672 Rx6-Yx6, G5
 1998 ESA/390        9672 Y56-YX6, G5 Turbo
 1999 ESA/390        9672 X17-XZ7, Z17-ZZ7, G6
 1999 ESA/390        7060-xxx Multiprise 3000, G5

 zSeries
 2000 z/Architecture 2064 100-116, 1C1-1C9, z900

An IBM Mainframe Installation

Contrary to public opinion, mainframes are hardly extinct. Organizations have huge investments in mainframe programming, and there are numerous applications where a centralized solution is the most efficient and secure. (Image courtesy of International Business Machines Corporation. Unauthorized use not permitted.)