From the Defender April 1981 Manual, 16P-3001-101 R-T

CPU/Video Board
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Requires Decoder ROM 2 at location 3K and Decoder ROM 3 at location 3E.

C8573 Interface Board
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Jumper W1 must be installed. W2 must be installed.

Rom Board - D8572
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For Red Label roms, insert the following jumpers:
W2, W4, W6, W7,
W9, W11, W13,
W16, W17, W20,
W21, W24

Note: ROM 5 is not used.