360 CPU panel

Mus.Cat. NEWUC:2010.52 Mnfctr: IBM Date: 1967 Ser. No: - Model: -
Comp: Control panel Height: 935 mm Width: 710 mm Depth: 130 mm Weight: 36 g

360 CPU panel

We still have the CPU panel.
There are 6 rows of 2 x 18 lights.
On the right hand side of the panel are 6 knobs,
that can be rotated to 6 positions,
which means 1.27 Kbits of data can be displayed.
It could be data in registers,
error status flags, current instruction, whatever ...
they were only used when the computer was stopped.

Below the lights are two rows of 32 switches,
that could be set as data to be input, because below them was -
24 switches that could set an address for the data to be stored.

At the bottom right are three knobs
that can be set to 8-16-16 positions.
This is the IPL (Initial Program Load) device address.
It was assumed that the device had at its beginning,
be it a card reader, disk drive, magnetic tape ...
data of the initial program that was read into memory
and control passed to it.

To start the computer an address was set in the 24 address switches,
(it was 1 switch down on the left and 2 down on the right)
the TIMER was DISABLED, and the ROS TRANSFER button was pressed,
this caused control of the CPU to be passed to an instruction in the firmware
that ran a program to set every bit of core storage to zero.
This was important to do because when a program failed,
and a core dump was taken it needed to be known what was changed.
A switch was then set to LOCAL to reset all registers and status bits.
Finally the LOAD button was pressed.

At the top right is a red knob, it was the emergency off.
It was never used, except once, when the computer was stopped for the last time.