Huh.
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8 bit ISA, 68k CPU, 16MHz clock crystal, TI memory controller, NEC and Motorola DSPs, two bios chips labeled 11001 PC17
Labeled (K) VOX 33101001 R2, A 851 0160/00 R1A A41, SA 201/PC R2A 8502, and Löpnummer 100061
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One of the traces from the pins looks deliberately cut and there's a "blue" wire on the other side of the board. It could also be accidental damage, the card was found in a pile of leaves, pine needles, spiders, and dirt, and I have no history on it at all. Surprisingly almost completely free of corrosion.
The bracket has two unlabeled 1/8" sockets and an unlabeled rotary rheostat.
I won't say *no* idea what it is, but not much of one.