Datascope System 98 Service Manual page 143

e Quad UART
The QUART device provides four independent full-duplex serial interface ports.
The Baud rates of the channels are independently programmable, which are
derived from an external 3.68MHz crystal oscillator. Three of the four channels
are defined in the DSS subsystem, while the fourth is reserved for R&D usage.
This device occupies 64 byte addresses on the 68020's bus.
Channel B - RS232
This interface connects the 68020 subsystem with external devices. This channel
is operated at a Baud rate of 9600
Channel C - Modem
This channel connects the 68020 to the internal Modem, which may be configured
by the user to Baud rates berween 1200 and 9600 Baud.
Channel D - Recorder
This channel allows the 68020 to control the optional AR-42 thermal array
recorder. It allows control and data to be sent to the recorder and status of the
recorder to be monitored. It is operated at a Baud rate of 38,400.
e Multifunction Peripheral
This device, as it's name implies, embodies several functions. It provides for eight
input lines which may be used as prioritized interrupt inputs, two sixteen bit
timers and a full-duplex serial channel. Two of the eight interrupt inputs are
used, one for the Shared Ram interrupt request from the Comm. Processor (see
below) and the other for the ACRTC interrupt request from the Display Controller
board. The serial channel is not utilized. This device occupies 32 byte addresses on
che 68020's bus.
e Display Controller Interface
This is a sixteen bit extension of the data bus that interfaces the 68020 to the
Display Controller PCBA, which acts a slave peripheral to the 68020. An interrupt
signal from the Display Controller synchronizes the 68020 to the Display
Controller video frame rate. This interface occupies two word (16 bit) addresses
on the 68020's bus.
e Shared RAM
The 68020 can access, to either read or write, the 1K byte static Shared RAM.
The 6809 and G8HC11 subsections can also access this device to pass data
between the subsections. This function is embodied in the Quad-port Static RAM.
System 98 Service Manual
Chapter 2, Theory of Operation
2-31