Re: parallel and serial port input/output

[Matthew Flatt <mflatt@cs.utah.edu>]

Quoting "Dan Anderson":
> What is the best way to communicate directly with the serial or parallel 
> ports?  [...]
> If possible I 
> would like to communicate directly with com1 and lpt1.  What would you 
> recommend?

One possibility is to use `open-input-file'/`open-output-file' on the
special filesnames "COM1" and "LPT1". For example:

 (define i (open-input-file "lpt1"))
 (define o (open-output-file "lpt1" 'append))

> I looked through documentation and found this for creating custom 
> ports.  Is this used for serial and parallel io?
> 
> (make-input-port    read-char-proc    char-ready?-proc     close-proc     
> [peek-char-proc]) 

No, that's not going to help much, unless you resort to a C-implemented
extension to create your own reader and writer functions.

Matthew