Table of Contents
Advertisement
Mask
MK or 46 with
QS-Q9
of 00 and
Qll
of 1
Description. This instruction, provided with the
Basic Interrupt special feature, is used to "mask" all
interrupts. Masked interrupts are not lost; they are
merely detained until the execution of an Unmask in-
struction. If the 1710 is in an interrupt subroutine
when the "unmask" occurs, the interrupts are further
detained until a Branch Out or Branch Out and Load
instruction is executed.
The Mask indicator (26) is turned on and off by the
Mask and Unmask instructions, respectively.
The P address,
Q.
and
QI0
positions of the instruc-
tion, are not used.
Execution Time.
T
=
160.
Unmask
UMK or 46 with
QS-Q9
of 00 and
Qll
of 0
Description. This instruction, provided with the
Basic Interrupt special feature, is used to "unmask" all
interrupts. It also places the 1710 in the interruptible
mode if the noninterruptible mode exists as a result of
a Mask instruction. The Unmask instruction operates
the same as a No Operation instruction when executed
without a preceding Mask instruction.
The Mask indicator (26), turned on by the execu-
tion of a Mask instruction, is turned off by the Unmask
instruction.
The P address,
Q.
and
QI0
positions of the instruc-
tion, are not used.
Execution Time.
T
=
160.
Branch Out
BO or 47
Description. This instruction, provided with the
Basic Interrupt special feature, is normally used in the
interrupt subroutine to return the 1710 to the main
program. The effect of this instruction is
to
branch the
program out of the noninterruptible mode. Execution
of this instruction within an interrupt subroutine
causes the following:
1,
The P address of the instruction is stored in IR-3.
This operation is necessary to restore IR-3 for use
when the next interrupt occurs. Therefore the P
address of this instruction is normally the address
of the interrupt identification routine.
2. The arithmetic indicators are restored to their
saved status, i.e, their on/off condition before the
interrupting condition was recognized.
3. The interruptible mode of operation is restored
if a Mask instruction is not in effect.
4. IR-l is placed back in normal use (that is, it is
used to obtain the address of the next instruction
to be executed) , and the computer returns to the
main program at the address that was saved in
IR-I.
141
71
P Address
I I
0
I
0
I I
0
I
L--.---J
To IR-3
In addition to the Op code and the P address, zeros
must be placed in
Qs' Q9'
and
Qll; Q7
and
QI0
are not
used.
Execution Time. T
=
200.
Branch Out and Load
BOLD-47
Description. This instruction, provided with the
Basic Interrupt special feature, operates in the same
manner as the Branch Out instruction, except that the
P
address is placed in IR-J and the address in IR-3 is
not disturbed. Thus, the instruction is used to return
the computer to the mainline program, but it does not
restore IR-3 to the address of the interrupt identifica-
tion routine. The computer does not branch to the ad-
dress saved when the interrupt occurred, but, instead,
the computer returns to the mainline program at some
other address. The address originally saved in IR-l
when the interrupt occurred is lost. The address in IR-3
is not affected, and if it is the address of the interrupt
identification routine it can be used by the next inter-
rupt.
I
4
I
71
P Address
1
I
0
1
0
1
I d
L--.---J
To IR-l
In addition to the Op code and P address, zeros must
be placed in
Qs
and
Q9
and a one must be placed in
Qll;
Q7
and
QI0
are not used.
Execution Time.
T
=
200.
Reading the Contents of TAS
and RTC into Core Storage
Select
TAS
Select Real-Time Clock
49
Advertisement
Table of Contents
