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Data
Bit
7
6
5
4
3
2
1
0
The Interrupt Request flip/flop is set By an attempt to write into
a protected location.
In addition to requesting an interrupt Cif jumpered appropriately)
the Interrupt Request flip/flop enables tbe board to respond to
the next Status Read CINP PEJ.
as a normal status read, which indicates what board is affected and
which IK blocks on that board are protected.
flip/flop is reset by the appropriate output command.
Because of the possible conflict during a status read if the Interrupt
Request flip/flop is set between a board select and the following
Status Read, it is suggested that all status reads be performed by
a subroutine which disables interrupts, selects a board, reads its
status, enables interrupts and returns.
To obtain the Interrupt Request feature, a jumper must be installed
to connect the RAM 4A to the desired Priority Interrupt line on the
back plane.
Figure- 2 illustrates the placement of this jumper.
TABLE- - 3
STATUS READ
I Same as
[ Address Bits
J (Board AddressI
Block 3 3
Block 2
l=Unprotected
Block 1
=Protected
0
J
Block 0
(The data in memory will not be affected,)
The bit definitions are the same
RAM 4A
User Guide
r i s
14
13
l 1 2
The Interrupt Request
See Table 3.
19
6
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