Radio Shack TRS-80 PC-2 - Page 13

ERL has same syntax as any other function which returns
a number in that a statement or variable must be used.
For example, PRINT ERL and I = ERL are both valid
uses.
To display error and end error line numbers if errors occur
in a BASIC program, use the following sequence:
100 ON ERROR GOTO 9000
9000 PRINT "ERROR"; ERN;" IN LINE"; ERL
ERN
Return Error Code
ERN
ERN is for use in error trapping in conjunction with ON
ERROR GOTO. ERN returns the number (i.e., code) of
the current error, or 0 if an error has not occurred.
ERN has the same syntax as any other function which
returns a
numeric quantity. For example, PRINT ERN
and B
= ERN are both val id uses. (See example for ER L.)
FEED
Transmit Carriage Return/Line Feed Sequences
FEED n
n is number from 1 to 65535 n is optional;
if omitted, 0 is used.
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FEED transmits a specified number of end-of-line
sequences (as
defined by CONSOLE). FEED interacts
with the RS-232C just as LF interacts with the printer.
For example, to transmit six end of line groups, enter:
FEED 6 (ENTER)
To list the current contents of an array A$ (10) with three
carriage return/I inefeed groups at the end of each string,
use a
command sequence similar to the following:
100 CONSOLE 0,0, 1
110 FOR I =0 to 10
120 PRINT #-8, A$(I)
130 FEED 2
140 NEXT I
Note
that FEED 2 will generate three end-of-line
sequences because
the first is automatically sent at the
end of the PR INT statement.
INPUT$
Input a String of Characters from the RS-232C
INPUT$
"prompt"; variable
prompt is the message you want displayed.
prompt is optional; if omitted, a question
mark (?) will be displayed.
variable represents
the data to be typed in.
INPUT$
is a variant of BASIC's INPUT function, differing
from
that function in two ways.
• INPUT$ requests its
data from the RS-232C, instead of
the keyboard.
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