Mitsubishi Electric Apricot LS Pro, Техническое описание оборудования

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System Board
Contents
Chapter 1
Chapter 2
Chapter 3
Chapter 5
Chapter 6
Chapter 3
3/18 LS PRO HARDWARE TECHNICAL REFERENCE
Parallel port
The parallel port is fully compatible with the IBM AT parallel port. The port is
output only and allows the attachment of peripherals that accept parallel data
at standard TTL levels.
A pinout and illustration of parallel port 25-pin D-shell connector is given at the
rear of section 2.
The parallel port is accessed via the three I/O ports given in the following table.
Address R/W Function
03BCh r/w Data register
03BDh read Status register
03BEh write Control register
These registers control the operation of the parallel port. They are described
in detail in section 5.
3.9 KEYBOARD/MOUSE CONTROLLER
General
The keyboard and mouse interfaces are implemented on the system board on
an Intel 8042 chip. The keyboard connector on the system unit is dedicated to
that function, the mouse connector can be used for any auxiliary device with
a serial interface compatible with the 8042. Illustrations and pinouts of these
connectors are at the rear of section 2.
The 8042 receives the serial data, checks the parity, translates the keyboard
scan codes and presents the data to the system as a byte of data at data port
I/O address 0060h. The interface can interrupt the system when data is available
or can wait for polling from the microprocessor.
I/O address 0064h is the command/status port. When the system reads port
0064h it receives status information from the 8042. When the system writes
to the port, the 8042 interprets the byte as a command.
The significance of port 0064h is described in section 5.
Keyboard password security
The 8042 provides a password security mechanism. Three commands are
available regarding password operation:
A 4 Test Password Installed
A 5 Load Security
A6 Enable Security