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Character Codes (Hexadecimal) (see notes)
Bits
Bits 0-3
4-7
0
1
2
3
4
5
6
7
B
9
A
B
c
D
E
F
0
NUL
SP
&
-
0
l
I
A*
J*
A
J
1
2
B*
K*
s·
B
K
s
2
3
C'
l
*
T*
c
L
T
3
I-·
4
D*
M*
u•
D
M
u
4
5
NL*
E*
N'
V'
E
N
v
5
6
F*
0*
W*
F
0
w
6
7
G*
P*
X*
G
p
x
7
8
H*
Q*
Y*
H
Q
y
B
9
I*
R*
Z*
I
R
z
9
A
¢
I
:
B
$
'
H
c
<
*
%
(<i)
D
(
)
'
-
E
I
;
>
-·
F
I
---.
?
"
Legend:
Examples:
*Codes (in addition to undefined codes) not assigned by the
alphameric keyboard
SP - Space
NUI. - Null
NL - New Line
Note:
Charact~r
code assignments other than those shown within the heavily
outlined portions of the chart above are undefined.
If an undefined
character code is programmed, the character that will be displayed is
not specified. The character displayed by the 2250 Model 3 for o
given undefined character code mny be different for other
device~.
IBM
reserves
the right to change at any time the character displayed
by thP 2250
for an undefined character code.
Figure 6. Character Set and Code Assignments
supplying a constant X and Y analog voltage to the
main deflection yoke. At the same time, the char-
acter deflection system forms a character by moving
the beam at high speed between various addressed
points in the character grid area. Figure 8 illus-
trates the strokes used to form the character "A"
and shows the character sizes in inches.
Table 1 lists the characteristics of a character
display. Character spacing (Figure 9) is an auto-
matic function of the 2250. After each character is
formed, the main deflection system automatically
moves the electron beam in the +X direction to the
new character area center point. The beam is
moved a distance of 14 raster units (when displaying
basic-size characters) or 21 raster units (when dis-
playing large-size characters). The program can
initiate additional spaces of 14 or 21 raster units
each by specifying space characters to the 2840.
Character
Byte Code
Bl or Cl
F9
A
9
%
6C
NUL
00
Table 1. Character Display Characteristics
Characteristics
Character Size
Basic
Large
Characters per line (max.)
74
49
Lines per display (max.)
52
35
Number of characters on display (max.)
3,848
1, 715
Character spacing (raster units)
14
21
Line spacing (raster units)
20
30
Hence, one space character results in a distance of
28 or 42 raster units between the center point of the
previously specified character area and the center
point of the next character area. The null character
does not cause a display and does not affect char-
acter-spacing circuitry.
2250 Operations
11
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