Radio Shack TRS-80 Model II Reference Manual page 194

Model II TRSDOS
KBLINE
Keyboard Line (function code 5)
~\
This routine inputs a line from the Keyboard into a buffer, and echoes the line
to the Display, starting at the current cursor position. As each character is
received and displayed, the cursor advances to the next position (Scroll Mode
~see
"Video Display" section on the following pages).
On entry to this routine, the input buffer is filled with periods, and these
periods appear on the Display, indicating the length of the input field for the
operator's convenience.
The line ends when a carriage return is typed or when the input buffer is filled.
A carriage return and erase-to-end-of-screen are always sent to the Display
upon termination of line input: a carriage-return is stored only if the Operator
actually pressed
miEil
Entry Conditions
(HL)
=
Start of input buffer.
B
=
Maximum number of characters to receive, () < B
A= 5
Actual number of characters input, including carriage return
() if input buffer was filled without carriage return. If line ended
with a carriage return, then C
=
X'()/Y
Exit Conditions
B=
c=
Control codes not listed below are placed in the buffer and represented on the
display with
~
symbols,
HEX
KEY CODE FUNCTION
l:fZM:ti;lAA3
08 Backspaces the cursor and erases a character.
OD
Terminates line. Clears trailing periods on display but
not in buffer.
Mi.l9.'ZJ
17
Fills remainder of input buffer with blanks, blanks
remainder of Display line.
@.I'illa
18
Fills remainder of input buffer with blanks, blanks to
end of Display.
I:m
1B
Reinitializes input function by filling input buffer with
periods and restoring cursor to original position.
~
1C
Backspaces the cursor to allow editing of line. Does
not erase characters.
~
1D
Advances the cursor to allow editing of line. Does not
erase characters.
Table 4.5. Received Control Codes, code
<
32
230