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(Continued)
Display size 4 can only be accessed by a display control instruction such as graph, label, or vector mode. Big
expand (256) must be added to the word selected (i.e., label is 1025 + 256).
A display program word can be a value from P, to 4095. The value is stored as a 12-bit binary word. The bits define
the type of word. Graphic representations used are defined as follows:
Most Stgnrflcanl Btt
11
0
2048
value
Changing the display size and beam intensity are controlled by setting various bits along with the control instruc-
tions and data words. These functions are called auxiliary functions to the instruction.
auxiliary functions
display size
(bex)
big expand
expand and shift (exs) , + 64
clear x position (clx) :
big expand (hex) :
expand and shift (exs) :
dim (dim):
bright (brt) :
Abbreviations within the parentheses are useful as a shorthand notation for writing display programs. They are not programming
codes.
8 4 P r o g r a m m i n g
10
9
8
7
0
x
x
x
1
1024
512
256
64
where x IS either a 1 (true) or a 0 (false)
11
10
9
0 ~l~0~x~x~x~s~x~x~e~x~x
, + 256
l
Resets the axis display position to the far left (0, y).
Amplifies the x and y CRT beam deflection by a 1.49 factor.
Amplifies the x and y CRT beam deflection by a 1.13 factor (expand) and shifts
the (0,O) reference point to the lower left of the CRT screen.
Sets the CRT beam intensity below the normal level.
Sets the CRT beam intensity to the maximum level.
5
4
3
2
x
x
x
x
32
16
4
8
7
6
5
4
3
2
(clx), + 16
clear x position
Least Slgnlflcant Bit
Decimal
1
0
total
1
0
2
1
1
0
beam intensity
(dim), + 8
dim
(brt), + 128
bright
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