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  1. Video Composition Planes 1

    We discussed the priority of output pixels in a previous article. It is common to consider video output as a stack of planes, where pixels in higher-priority planes hide all those of lower priority. Pixels in Pole Position are clocked out at 6.144 MHz on the rising edge of …

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  2. Sprites 3

    16x16 Sprites

    Debris and Parts

    The car parts and debris ejected from a crash are 16x16 sprites. Here are some examples:

    Tire 4 Manifold Carb

    Announcements

    16-pixel sprites are used for the various announcements:

    Goodyear Blimp

    Prepare To Qualify

    Prepare To Race

    GAME OVER

    16-Pixel Cars

    In addition to the 32-pixel player and opponent cars, half-size 16-pixel versions are also present in the sprite …

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  3. Sprites 2

    More 32x32 Sprites

    Explosions

    Six sequential two-sprite bitmaps make an explosion. In conjunction with an uncontrolled car, this makes:

    Pole Position 32x32 Explosion Animation

    In the actual game, a number of car parts also project from the explosion.

    Marquees

    Similar to the cars, clever use of palette permutations allows sequences of sprites to contain different …

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  4. Sprites 1

    Following on our investigation of the Namco 04xx, here we look at the sprite bitmaps found in Pole Position. We know that both 32x32 and 16x16 sprites are supported by this hardware.

    Data Flow

    Sprite bitmap ROMs are found on Pole Position schematic sheet 14B. We find that five pairs …

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  5. Namco 04xx And Sprites

    Chip Pins

    An online reference from Dig Dug reveals the following.

    Namco 04xx Pins

    The following restates that table with connection information in Pole Position.

    Pin Name IO Signal in Pole Position
    1 1H I HPOS0(1H)
    2 2H I HPOS1(2H)
    3 /HSYNC I /HSYNC
    4 H4 O H4*
    5 H8 O …
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  6. Namco 07xx

    There are two Namco 07xx custom chips in Pole Position: one on the CPU board and one on the video board. They perform the same function on each board, which is to determine the exact position of the CRT beam.

    Only the 07xx on the video board is directly related …

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  7. Colors

    There are various ways to interpet the colors available in Pole Position.

    The final output of the video hardware is realized with a 12-bit digital-to-analog resistor network. Because of this, Pole Position might generously be called a 4096-color game.

    The wikipedia article states that 3840 colors are available. Not sure …

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  8. PAL-1

    There are two Z8002 CPUs in Pole Position, labelled A and B. Each has a custom logic chip labelled PAL-1. Here is a portion of the schematic redrawn.

    Pole Position PAL-1 Equivalent Circuit

    Chip Analysis

    It's evident from the analysis that PAL-1 decodes certain Z8002 bus transactions, and generate signals to complete those transactions.

    Silicon …

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