Functions Noted Above The Keys; Screen; Physical Lines And Logical Lines; Virtual Screen - Casio FX-890P Owner's Manual

1.4.2 Functions Noted Above the Keys

The BASIC one-key commands, and the symbols and commands noted above the
keys are entered when the corresponding keys are pressed following the Shift key.
Note, however, that pressing the numeric keys ( 0 - 9 ) after Shift in the CAL
mode executes the BASIC program in the corresponding program area.
EXAMPLE:
Operation
Shift Z 
Shift * 

1.5 Screen

The screen is a 32-column x 2-line liquid crystal display. Characters are formed by a
5 x 7 dot matrix.

1.5.1 Physical Lines and Logical Lines

The maximum display capacity of one line is 32 columns, but internally the unit is
capable of handling lines up to 255 characters long. The display capacity line (32
characters) is referred to as the physical line, while the internal capacity line is called
a logical line. A logical line is a continuous line of characters in which any column on
the extreme right of the screen is not a null.
One physical line →
One physical line →
Pressing Shift  moves the cursor to the beginning of the logical line, while Shift
. moves the cursor to the end of the logical line. These operations are useful in
determining the extent of logical lines.

1.5.2 Virtual Screen

The screen can display four lines at one time, and as the 5
scrolls off the top of the screen. Lines that scroll off of the screen can, however, be
brought back into view using the cursor (  /  ) keys, because the unit is able to
store up to eight lines internally. These eight lines make up the virtual screen, while
the four lines actually displayed are called the actual screen.
Virtual screen (8 lines)
Display
PRINT
NPR(
1+2+3+4+5+6+7+8+9+10+11+12+12+14
+15+16+17_
One logical line, from the first character to the last
1 AAAA
2 BBBB
3 CCCC
4 DDDD
5 EEEE
6 FFFF
7 GGGG
8 HHHH
th
11
line is input, the first line
Actual screen
(4 lines)