TIA 1A - TELEVISION INTERFACE ADAPTOR (MODEL 1A)

GENERAL DESCRIPTION

The TIA is an MOS integrated circuit designed to interface between an eight (8) bit microprocessor and a television video modulator and to convert eight (8) bit parallel data into serial outputs for the color, luminosity, and composite sync required by a video modulator.

This circuit operates on a line by line basis, always outputting the same information every television line unless new data is written into it by the microprocessor.

A hardware sync counter produces horizontal sync timing independent of the microprocessor. Vertical sync timing is supplied to this circuit by the microprocessor and combined into composite sync.

Horizontal position counters are used to trigger the serial output of five (5) horizontally movable objects; two players, two missiles and a ball. The microprocessor can add or subtract from these position counters to move these objects right or left.

The microprocessor determines all vertical position and motion by writing zeros or ones into object registers before each appropriate horizontal line.

Walls, clouds and other seldom moved objects are produced by a low resolution data register called the playfield register.

A fifteen (15) bit collision register detects all fifteen possible two object collisions between these six (6) objects (five moveable and one playfield). This collision register can be read and reset by the microprocessor. Six input ports are also provided on this chip that can be read by the microprocessor. These input ports and the collision register are the only chip addresses that can be read by the microprocessor. All other addresses are write only.

Color luminosity registers are included that can be programmed by the microprocessor with eight (8) luminosity and fifteen (15) color values. A digital phase shifter is included on this chip to provide a single color output with fifteen (15) phase angles.

Two (2) independent audio generating circuits are included, each with programmable frequency, noise content, and volume control registers.

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