
47
0000
0001
0002
0003
0201
0101
0004
Block
a
Block
b
Address
Instruction
Operands
000
LD
0000
001
AND NOT
0001
002
LD
0002
003
AND
0003
004
OR
0201
005
OR
0004
006
AND LD
—
007
OUT
0101
Although the following diagram is similar to the one above, block b in the dia-
gram below cannot be coded without separating it into two blocks combined
with OR LOAD. Here the three logic blocks are coded first followed by the
two logic block instructions required to combine them. When coding the logic
block instructions together at the end of the logic blocks they are combining,
they must, as shown below, be coded in reverse order, i.e., the logic block
instruction for the last two blocks is coded first, followed by the one to com-
bine the execution condition resulting from the first logic block instruction and
the execution condition of the logic block third from the end, and on back to
the first logic block that is being combined.
0000
0001
0002
0003
0102
0004
0104
Block
a
Block
b
Block
b2
Block
b1
Address
Instruction
Operands
000
LD NOT
0000
001
AND
0001
002
LD
0002
003
AND NOT
0003
004
LD NOT
0004
005
AND
0104
006
OR LD
—
007
AND LD
—
008
OUT
0102
When determining what logic block instructions will be required to code a dia-
gram, it is sometimes necessary to break the diagram into large blocks and
then continue breaking the large blocks down until logic blocks that can be
coded without logic block instructions have been formed. These blocks are
then coded, combining the small blocks first, and then combining the larger
blocks. Either AND LOAD or OR LOAD is used to combine the blocks, i.e.,
AND LOAD or OR LOAD always combines the last two execution conditions
that existed, regardless of whether the execution conditions resulted from a
single condition, from logic blocks, or from previous logic block instructions.
When working with complicated diagrams, blocks will ultimately be coded
starting at the top left and moving down before moving across. This will gen-
erally mean that, when there might be a choice, OR LOAD will be coded be-
fore AND LOAD.
The following diagram must be broken down into two blocks and each of
these then broken into two blocks before it can be coded. As shown below,
blocks a and b require an AND LOAD. Before AND LOAD can be used, how-
Complicated Diagrams
Basic Programming
Section 3-4