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are also selected on location B9 with jumpers.
instance, address bit
responds, then pins 4 and 13 would be jumpered together.
If address bit A2 was desired to be a 1, then either pins
3 or 13 may be jumperd together, since 13 and 14 are tied
to the common address selection input.
It is suggested, however, that when jumpers are being used,
pins 3 and 13 be connected together to provide an easy
visual indication of whether the address bit is a
since that will correspond to whether the jumpers are
0
slanted or straight across the jumper socket.
and 14 were tied together so that an
can be inserted in this location and used to select the
address.
Address bits 3, 4, 5,
manner.
5,
and 7 are jumpered on position C
6
on the previous page for pin numbers for each address bit.
If it is desired to use the board in a memory-mapped I/O
capacity, then in position B9 the jumpers between pins
and 9 and 5 and 12 must be removed and two jumpers in
8
serted between pins 7 and 10
remaining jumpers for bits 2 through 7 function exactly
the same and affect the lower eight bits of the memory
address.
be all ones, that is hex FF._or octal 377.
When used as a memory-mapped I/O board, all instructions
that normally affect the memory will operate on the I/O
ports.
For example, an increment memory instruction would
read the data from the addressed input port, increment
that data by one and output it on the same address output
port.
8
24
2
6
Address bit 3 is also on location 39; address 4,
The upper eight bits of the address will always
is desired to be a
8
and 7 are jumpered in a similar
.
8
and between
PIO 4, Rev. 2
User Guide
If, for
when the board
0
or a
1
Pins 13
position DIP switch
See the diagram
and 11.
The
6
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