Chapter 4. Operator Interface; Display - IBM 3742 Reference Manual

DISPLAY
Station status information, data, and program information
are displayed for operator use on a display screen. On the
3741, the station uses six 40-character lines of display. Line
1 indicates station status. Lines 2, 3, 4, and the first eight
positions of line 5 display either data or program informa-
tion, depending upon the display mode selected. The last
30 positions of line 5 and line 6 are used for the operator
guidance feature_ Figure 14 shows information on the dis-
play screen. On the 3742, each operator station uses three
40-character lines of display: line 1 for station status and
lines 2 and 3 for data or program information. Figure 15
lists status line positions for both the 3741 and the 3742.
The 3742 uses one line for displaying status, leaving only
two 40-character lines for data. In order to view 128 char-
acters of data in two lines, scrolling capability was incor-
porated into the 128 feature. Scrolling changes the portion
of the 128-character record that is displayed. Three display
modes are used_
Status
Line
3
A A
Chapter 4. Operator Interface
Display mode A shows characters 1 through 40 on the first
data display line and characters 41 through 80 on the
second line. Display mode B shows characters 41 through
80 on the first line and characters 81 through 120 on the
second line. Display mode C shows characters 81 through
120 on the first line and characters 121 through 128 on the
second line.
The choice of display mode is controlled by the position of
the cursor. When the cursor moves forward from character
position 80 to 81, the display changes from mode A to mode
B.
Moving the cursor from position 120 to 121 changes
the display from mode B to mode C. Moving the cursor
beyond position 128 (to 000) does not change the display.
When a record advance occurs, the display returns to mode
A unless the cursor is moved, by means of leading automat-
ic fields, past position 80.
When the cursor moves backward from position 121 to 120,
the display changes from mode C to mode B. Moving the
cursor from position 81 to 80 changes the display from
mode B to mode A.
Cursor
01001
E R
ACME CORPORATION
112 MAIN ST _~---I
ADDRESS
112
MAIN ST/////////////////////
Guidance Message
Figure 14. Display Unit with Operator Guidance
Operator Interface 19