Theory Of Operation 2.2.2 - Panasonic JB-3300 Technical Manual

THEORY OF OPERATION
General
The logic unit actually consists of two boards, the CPU board and the I/O
board.
The nerve center of the logic unit has a microprocessor (8088) and DMA
controller (8237A-5). The logic unit contains a controller for the memory
and Principal input and output equipment.
The principal functions of the logic unit are:
[CPU board]
Accessing 16K bytes BIOS program ROM
Control of standard 256K bytes, maximum 512K bytes, RAM
Direct memory access (DMA) between memory and I/O
Interrupt control of eight interrupt levels
Peripheral I/O interface
PDP controller
Keyboard interface
Interval timer/Speaker interface
"DIP" switch
[I/O board]
(6) Peripheral I/O interface
FDD controller
Parallel port (printer)
Serial port (RS-232C)
Two option slots
Slots for HD controller board
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