The TORCH Graduate User Guide Issue 1.00, Nov 1984 The ...

The TORCH Graduate User Guide Issue 1.00, Nov 1984
5. The Serial and Parallel Ports
Since the BBC Micro comes with both serial and a parallel
ports readily available, these have been implemented for use in
MSDOS and will always be the last devices in the IjO list. Thus if
a RS232 expansion card is fitted, it will have the device
designation COM1 and the BBC micro's serial port will become COM2.
Note that some baud rates are not available to the user (see
page 18) and that some of the control signals associated with the
back of a PC expansion card are not present on the serial and
parallel ports. You will find that programs using serial IjO work
a lot better if output to the screen is turned off (e.g. use print
rather than TYPE with "P). This is primarily caused by the BBC
microcomputer spending most of its time updating the display when
any screen activity occurs.
If you are using a program that makes heavy use of the ports
or uses serial lines not available on the BBC then the use of an
IBM expansion card is recommended.
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