[SD-User] Re: Oddities in SDC 10.14

[Paul O'Kane]

----- Original Message ----- 
From: "Martin Davies G0HDB" <g0hdb at amdavies.demon.co.uk>

> Is there perhaps a slight difference between the code that
> drives the speaker and that which drives the LPT1 port for
> keying the rig?

Yes, there is a difference.  When driving the speaker, I
simply use a SOUND command for the appropriate length of
time for each dot or dash - this puts practically no load
on the processor.  However, CW from the serial or parallel
ports is different, as the processor is placed in a hard
loop for each dot or dash - the number of iterations in
each loop is processor dependent and is calculated following
the CALIBRATE command.

If there are no other demands on the processor, the keying
will be consistent (in terms of timing).  It looks like
your OS may be doing something in the background?  Of couse,
it couldn't possibly be anything wrong with SD :-)

73,
Paul EI5DI