• Generates 3.58 MHz Master Clock for the CPU printed circuit
board.
• Generates Power-On Reset for the CPU printed circuit board.
• Performs parallel/serial data conversion between the CPU
printed circuit board and the peripherals.
• Provides driving circuitry for the Key-Press signal from the
CPU printed circuit board to the Console Speaker.
• Converts signals from the various hand controllers into
recognizable data for the microprocessor.
• Buffers and drives the data lines between the CPU printed
circuit board, the RAM Memory pcb(s), and the remainder of
the system.
• Performs the first Memory Map decoding of the possible 64K
address locations to 8K blocks for the microprocessor.
• Generates control signals for the peripheral devices.
• Receives video data from the CPU printed circuit board,
converts it to a composite video and routes it to the Power
Supply pcb.
• Combines the sound from the computer system and the audio
track of prerecorded cassettes.
• Develops the sound subcarrier for the television audio as
part of the composite video.
4.2.2 Central Processing Unit
The Central Processing Unit (CPU) printed circuit board (pcb)
performs the function of controller for the entire Console system.
The CPU pcb contains the 6502 Microprocessor, the ANTIC chip (a
specialized microprocessor) and the CTIA chip, which generates the
video signals for the system. The CPU pcb controls the Console system
and its peripheral devices through address lines (to select which
device it needs to communicate with) and data lines (to transmit or
receive data from a selected device) common to the entire system.
Operating instructions for the microprocessor come from the ROM
Operating System on the Personality pcb. Additional functions of the
CPU pcb are:
4-2 System Service Manual
To Next Page
Loading...
Need help?
General
