Returns or changes the maximum parallel I/O port speed,
for port 1. This object is only supported if this port
is a parallel port. An eSlow setting causes a 10 us
busy pulse per received byte of data. An eFast setting
causes a 1.5 us busy pulse per received byte of data.
In rare cases, setting this value to eFast can cause the
parallel port to no longer transfer data reliably.