ACT apricot - Page 305

INTRODUCTION
The Apricot has, in addition to a parallel port, a serial
RS-232 data port which can be connected to a wide variety
of
external hardware add-ons. The hardware that controls
the port is the Z80A SIO (Serial Input/Output) chip. The
Apricot is capable of transmitting at a rate of up to 19200
BAUD (Bits per second).
APPLICATIONS INTEREST
Most communication with the ports and thus with the
outside world should take place through the particular
applications language being used. However, the Apricot
Control Device is an easy and powerful way of configuring
and using the port. For more information see the section
concerning the control device.
SYSTEMS INTEREST
The serial communications driver manages 1 RS-232C
port on the Apricot computer. The driver provides for only
asynchronous data transfer at speeds from 75 baud to 19200
baud. An interrupt driven interface is provided as well as
two dynamic length queues to provide character buffering
whilst the interface or application is otherwise occupied.
The serial port is located in port A of the Z80-SIO and
utilises the following controVstatus signals
RTS - Request To Send (pin 4)
CTS - Clear To Send (pin 5)
DCD - Data Carrier Detect (pin 6)
DTR-Data Terminal Ready (pin 20)