S/360 Front Panels

These IBM System/360 front panel illustrations were inspired by those on John Savard's quadibloc website, but are being recreated to have much more accurate detail (work in progress - as of April 2026 there's just the final 9X panel to do). 9020 models have also been added. Although the casual term “front panel” is commonly used today, IBM documentation refers to it as the “system control panel”.

Note that some linked pictures of actual front panels may show incorrectly coloured indicator lamps (round) and/or push buttons (rectangular) or incorrect rotary switch knobs. Originals were sometimes missing and have been replaced with similar but incorrect substitutes by current owners, or inadvertently swapped locations. The illustrations below are correct and agree with the relevant IBM sources.

IBM S/360 Model 20

IBM S/360 Model 22

IBM S/360 Model 50 – 9020 IOCE

IBM S/360 Model 50 – 9020A CE

IBM S/360 Model 65

IBM S/360 Model 65 – 9020D and 9020E CE

IBM S/360 Model 67

IBM S/360 Model 75

IBM S/360 Model 85

IBM S/360 Models 91, 95, 195

IBM S/360 Model 20

The blank panel on the left could be removed to expose the Customer Engineer console. The panel to its right was for the optional Communications Adapter feature (illustrated), the primary means of data interchange with other S/360 systems.

Click here to view a standard Model 20 front panel (bottom) and one with the Communications Adapter feature (top)

IBM S/360 Model 22

Click here to view a Model 22 front panel

IBM S/360 Model 25

Click here to view a Model 25 front panel

IBM S/360 Model 30

The Model 30 was available with either one or two integrated selector channels for input/output. Both versions are illustrated below.

The lower left operator control panel is for a machine with the Interval Timer feature installed. Without this feature the top right Enable/Disable switch on this panel would be a white dummy button.

Model 30 with one selector channel

Click here to view a single selector channel Model 30 front panel

Model 30 with two selector channels

Click here to view a dual selector channel Model 30 front panel

IBM S/360 Model 40

Click here to view a Model 40 front panel

IBM S/360 Model 44

The Model 44 was unique in having one or two internal disk drives. The two rows of four pushbuttons at bottom left controlled these drives. If only one drive was installed the top row of four pushbuttons were white blanks.

Click here to view a Model 44 front panel

IBM S/360 Model 50

The standard Model 50 is illustrated, which had a printed diagram of its internal logic towards top right. In machines fitted with optional additional storage this sub-panel contained margin controls instead, similar to those on the top left sub-panel.

Click here to view a standard front panel, and here for one with additional storage

IBM S/360 Model 50 – 9020 IOCE

The standard Model 50 was modified to create the Input Output Control Element of all 9020 systems (i.e. A, D, and E versions). The IOCEs in 9020E systems incorporated Channel-To-Channel (CTC) adapters to exchange data with the associated 9020D. On 9020A and 9020D IOCEs the CTC sub-panel (illustrated below with two toggle switches and green indicators) was blank.

Click here to view a standard front panel and here for a CTC version

IBM S/360 Model 50 – 9020A CE

The standard Model 50 was modified to create the Compute Element (CE) of the 9020A system (the 9020D and 9020E CEs were modified Model 65s - see below). Note the reduction from four to three indicator rollers. This is because all input/output circuitry was removed (instead the IOCE, illustrated above, was used for I/O) resulting in fewer indicators being required. No other S/360 front panel had three rollers.

Click here to view a 9020A CE front panel

IBM S/360 Model 65

Click here to view a Model 65 front panel

IBM S/360 Model 65 – 9020D and 9020E CE

The standard Model 65 was modified to create the Compute Element (CE) of the 9020D and 9020E systems. The D and E CEs were externally, internally, and logically identical, except the E CE had an internal 1052 (console terminal) adapter installed. The E CE front panel had a 1052 enable/disable toggle switch on a left hand side panel (shown below with a green indicator light). This panel was blank on a D CE.

Click here to view a 9020E front panel

IBM S/360 Model 67

The Model 67 was a Model 65 with an added Dynamic Address Translation (DAT) frame and logic. There were two versions. The 67-1 was a uniprocessor. The 67-2 was designed as a dual processor (duplex) but could be installed as a single processor (half-duplex).

Model 67-1

The front panel of a 67-1 was identical to a Model 65, except for a few minor differences in roller labelling (the DAT frame had its own control panel). The centre left sub-panel was normally blank but could hold from one to four rotary switches, as illustrated. These were present if the optional Floating Addressing feature was installed.

Click here to view a Model 67-1 with rotary switches

Model 67-2

The front panel of a 67-2 was the same as a 67-1 except for minor differences in the voltage sub-panel (top left) and operator sub-panel (bottom right). The centre left sub-panel was always blank as there was no optional Floating Addressing feature for the 67-2.

Click here to view a Model 67-2

IBM S/360 Model 75

Click here to view a Model 75

IBM S/360 Model 85

The Model 85 replaced individual indicators with a CRT display and most key switches with an adjacent vertical 4x4 keypad. An optional feature allowed the display to be switched to Operator Console mode and added a conventional alphanumeric keyboard positioned on the reading board below the display (not shown). The top right cover panel could be raised to reveal CE controls.

Click here to view a Model 85 with the Operator Console feature installed and the CE controls revealed

IBM S/360 Models 91, 95, 195

This is the Model 91 front panel. Almost the same front panel appeared on the Model 95 and the Model 195.

The operator controls (Load and Interrupt pushbuttons, Load Unit Address rotary switches, etc.) found on the other front panels were located on a separate panel, shown below, on the 91, 95, and 195 models.

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