1015
Text String Processing Instructions Section 3-31
Description LEFT$(652) reads the number of characters designated by S2, from the left
(the beginning) of the first word of the text string designated by S1 until the
NUL code (00 hex), and outputs the result to D (with NUL added at the end).
If the number of characters fetched exceeds the number of characters desig-
nated by S1, the entire S1 text string will be output.
If 0 (0000 hex) is designated as the number of characters to be read, the two
NUL characters (0000 hex) will be output to D.
Flags
Precautions The maximum number of characters to be read that can be designated by S2
is 4,095 (0FFF hex). If more than that are designated, an error will be gener-
ated and the Error Flag will turn ON.
If 0000 (hex) is output to D, the Equals Flag will turn ON.
Example In this example, LEFT$(652) is used to read four characters.
Index Registers ---
Indirect addressing
using Index Registers
,IR0 to ,IR15
–2048 to +2047 ,IR0 to –2048 to +2047 ,IR15
DR0 to DR15, IR0 to IR15
,IR0+(++) to ,IR15+(++)
,–(– –)IR0 to, –(– –)IR15
Area S1 S2 D
Name Label Operation
Error Flag ER ON if more than 4,095 characters are designated by S1.
ON if more than 4,095 characters (0FFF hex) are desig-
nated by S2.
ON if the Communications Port Enabled Flag for the com-
munications port number specified as the Com Port num-
ber for Background Execution is OFF when background
processing is specified (CP1H only).
OFF in all other cases.
Equals Flag = ON if 0000 (hex) is output to D.
OFF in all other cases.
43 44
D
S2: D200
D: D300
S1: D100
D101
D102
D103
D100
D200
D300
Text string ABCDE
Text string ABCD
Four characters
(bytes) read.
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