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Error status information is reset.
System Reset key is found on logic
page PA 101.
Description
Pressing the system reset key causes a
system reset function to occur.
The
system reset function causes all
hardware registers to be set to zero
with proper parity.
All hardware latch-
es are reset with the exception of the
machine reset latch, which is set on.
The machine reset latch disables all
traps until it is reset.
PreSSing the
start key starts the machine at a micro-
program that clears all UCW'S (Unit
Control Words).
After the UCW's are
cleared, the machine reset latch is
reset and traps may occur.
When the
machine reset latch is reset, the system
reset function is over.
Note:
The ROAR
Reset key may be pressed prior to press-
ing the start key to prevent clearing
the UCW'S (see ROAR Reset key) •
D
OU
Ie
B
D
~
TEST
B B
I
DISPLAY
I
Figure
6-5.
Control Keys
ROAR RESET KEY
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Allows manual change of ROAR address
by gating contents of switches F, G,
H, and
J
into ROAR.
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The ROAR reset key is effective when
the clock is running.
6-12
•
•
Can also be used to block the clear-
UCW routine after a system reset.
ROAR Reset switch is located on
logic page PA 111.
Description
To manually change the address in WX,
the CPU clock must
be
stopped.
Pressing
the ROAR reset key turns on the gate
switches to WX stacking latch.
When the
clock is re-started and traps are
allowed to take place according to their
aSSigned priority, the gate switches to
WX stacking latch, forces an address
into WX, which locates the trap to gate
the switches to WX.
The ROA.R reset key also alters the
events that take place after a system
reset function.
A system reset function
resets all registers and latches except
the machine reset latch, which is turned
on.
The machine reset latch forces an
address of 0000 to ROAR.
If ROAR reset
is pressed after a system reset
function, but before the CPU clock is
started, the machine reset latch is
turned off.
Then, when the clock is
started, the clear UCW's trap is not
taken.
Other traps of higher priority
may take place before the gate switches
to WX trap takes place.
SET IC KEY
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Allows manual setting of instruction
counter from console.
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Forces ROS branch to 0001, which is
the address of the Set IC Trap.
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Set IC key is inoperative if CPU
clock is running.
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Set IC key is located on logic page
PA 101.
Description
The Set IC key is used to change the
core storage address in the instruction
counter (registers I and J).
PreSSing
this key forces the address 0001 into
WK, and starts the CPU clock.
Located
at ROS-address 0001 is the routine that
sets I and J from switches F, G, H, and
J.
After entering IJ, the address is
also gated into the A- and B-registers
so it will be displayed on completion of
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