Switches - Control Data 3100 Reference Manual

SWITCHES
Switches associated with a 3100 Computer are classified as console switches and keyboard
switches. Console switches include the following:
• The EMERGENCY OFF switch.
• A group of operator/maintenance switches on the console main-frame.
• The Breakpoint switch assembly (Figure 5-8).
Keyboard Switches
The console keyboard switches are used for entering data manually into the computer
and for controlling its operation. A front view of the keyboard appears in Figure 5-7 and
Table 5-1 describes the function of the keyboard switches.
Console Switches
EMERGENCY
OFF
SWITCH -This red rectangular momentary switch is used to remove
power from the whole computer system in case of a fire or other emergency. It should not
be used for a normal power shutdown. Refer to the SOURCE POWER OFF switch de-
scription in the Power Control Panel description of this section.
OPERATOR/MAINTENANCE SWITCHES -Table 5-2 describes the operator/maintenance
switches located on the console main-frame.
BREAKPOI NT SWITCH ASSEM BLY - The Breakpoint switch is a six-section, eight-posi-
tion, thumb-wheel switch. The left-hand wheel selects the operating mode, and the other
five wheels specify a register number or storage address. There are four mode positions
on the mode selector switch with an OFF position between each mode; these modes are
BPI, BPO, REG, and STO.
BPI and BPO Modes: The address on the S Bus is continually compared with the instruc-
tion or operand address specified by the Breakpoint digit switches. When the selector
switch is set to BPI, the computer stops if these values become equal during an RNI (Read
Next Instruction) sequence. When the mode selector switch is set to BPO, the computer
stops if these values become equal during an ROP (Read Operand) or STO (Store) sequence.
REG and STO Modes: In these two modes, the operator may either monitor the contents
of a register location or storage address specified by the thumb-wheel digit switches, or
he may store a word in these locations. To monitor a storage location:
1.
Set the mode selector to REG (register file location) or STO (storage).
2.
Set the Breakpoint switch to the desired register number or storage address.
3.
Press the READ STO switch on the keyboard.
4.
Adjust the Auto Step control to vary (he display rate.
The register or storage contents are repeatedly displayed in the Communication register
at the selected repetition rate until another keyboard button is pressed to release READ
STO. To write a word in storage:
1.
Set. the mode selector to REG or STO.
2.
Set the Breakpoint switch to the desired register number or storage location.
3.
Press the WRITE STO switch on the keyboard.
4.
Enter data into the Communication register by depressing the numeric switches
and finally the TRANSFER switch.
The data is entered into the desired storage location or Register File location at the end
of the instruction that is currently being executed by the computer. Pressing any other
register or mode selector switch releases WRITE STO operation.
5-7