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Programming Commands
Programming using DOS routines
Control characters and special functions
For special display functions, there are some commands which will
be explained in this chapter. Some of the commands consist of one
ASCII-CTRL-code, others are command strings, introduced by
ESC.
If a command needs additional parameters, please do not forget to use
ASCII format for the parameter. That means, if the parameter is 0
(zero), then you have to transmit the ASCII code "0" (=CHR$(48)
in Basic; 48 is the decimal position of the "0" character in the
ASCII code table). But please consider that only ONE byte is
allowed for each parameter. That is why you cannot transmit two-
digit numbers. In this case, just add the number you want to
transmit as parameter 48 and transmit the corresponding character.
For example, if you want to transmit the parameter 11, you have to
send CHR$(11+48)=CHR$(59)=";". Attention: For some other
commands, only BYTE values are allowed as parameter. For those,
you directly send the corresponding character code without adding
48 (e.g. CHR$(11) for 11). For details, please refer to the individual
command code descriptions.
Example: Set the cursor to the last position in the display area
Example:
OPEN "COM1: 9600, N, 8, 1, DS0" FOR OUTPUT AS
#1
PRINT #1, "Hello World!"
CLOSE #1
You can also generate a display output using the simple DOS
routines.
Example:
MODE COM1: 9600, N, 8, 1
ECHO Hello! >COM1:
1 8
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