STATUS and CONTROL registers for the serial interface are given below.
READIO and WRITEIO registers for the PC serial interface are also given below. These registers are different than the hardware registers on an HP BASIC RS-232 Interface. The READIO/WRITEIO registers allow direct access to the interface hardware. You should not attempt to use these registers unless you are familiar with the PC RS-232C hardware. You should not mix use of READIO/WRITEIO with STATUS/CONTROL statements. Using STATUS/CONTROL statements is preferred.
The ON INTR and ENABLE INTR statements are supported by this interface. The values for the enable mask in the ENABLE INTR statement are the same as those for STATUS register 8, given below.
