Remove the top cover and look at the logic board. It will match one of the following descriptions.
There is a daughter board marked DDF6112.
U133 is 9.8304 MHz.
U129 (MACH 110) is marked "DOPWFRM VER 1.14".
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Stencil in upper left is DDF6102B.
U133 is 9.8304 MHz.
U129 (MACH110) is marked "DOPWFRM VER 1.14".

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Stencil in upper left is DDF6102C.
U133 is 9.8304 MHz.
U129 (MACH111) is marked "DOPWFRM1 V2.00"

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Stencil in upper left is DDF6102D.
U129 (MACH111) is marked "DOPWFRM1 V2.00"
U133 is either 9.8304 or 9.2160 MHz. The 9.8304 MHz oscillator is used in the DDF6000D and the DDF6100D. The 9.2160 MHz oscillator is used in the DDF6000d and DDF6100d.

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Stencil in upper left is DDF6102E.
U124 (MACH211) is marked either WAV2PH V110 or V111. Version 110 is used in DDF6001e. Version 111 is used in DDF6001f and DDF6002f.
U115 is 9.2160 MHz.

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