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--- notes_20for_20risc_20os_20users [2018/03/31 13:19] – external edit 127.0.0.1
+++ notes_20for_20risc_20os_20users [2024/01/05 00:21] (current) – external edit 127.0.0.1
@@ Line 24: / Line 24: @@
 ==== Serial device ====
  On windows the serial device can be opened for input //and// output on the same channel, whereas on RISC OS the serial device has to be opened seperately for input and output.\\
+<code bb4w>
     REM Open serial device on Windows
     ser%=OPENUP"COM1: 9600,8,N,1"
@@ Line 30: / Line 31: @@
     serin%=OPENIN("Serial:")
     serout%=OPENOUT("Serial:")
+</code>
 \\  If you are converting code and are tempted to use:\\
+<code bb4w>
     serin%=OPENUP"COM1: 9600,8,N,1":serout%=serin%
+</code>
 you must be careful not to close both **serin%** and **serout%**, as both variables point to the //same// channel. The following will give an error when trying to **CLOSE#serout%** as it is trying to close an already closed channel:\\
+<code bb4w>
     CLOSE#serin%:CLOSE#serout%
+</code>
 Code similar to the following should be used, also using the code to prevent multiple cascading errors on closing (see [[/Forcing%20a%20variable%20to%20exist|Forcing a variable to exist]]):\\
+<code bb4w>
     IF serin%=serout% THEN serout%=0
     IF serin% THEN temp%=serin%:serin%=0:CLOSE#temp%
     IF serout% THEN temp%=serout%:serout%=0:CLOSE#temp%
+</code>