Mystery card with two 16-pin connectors

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Mystery card with two 16-pin connectors
This unlabeled board for an Apple II computer is one I'm curious about and haven’t been able to identify.  It has a 16-pin connector at the front and another at the back that I don’t understand the purpose of.  The only manufacturer marking I can find is the number “252” at the bottom edge.  Some of the chips have 1982 date codes.  I dimly recall picking it up for $5 at a computer store clearance sale decades ago because it reminded me of my Synetix 294KB SSD (solid state drive) card for the Apple II Plus.  That was because of its shape and the large number of chips, with no microprocessor and no EPROMs.    As you can see in the photos it’s quite dusty and I think it was probably that way when I bought it.  Anybody recognize it?  Thanks.
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It looks like one 16-pin

It looks like one 16-pin header and one 14-pin header, not two 16-pin headers.

For sure this is not a memory card, as the only components are SN74LS_ TTL chips.

 

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You’re right, one 16-pin header and one 14-pin one

You're right, of course.  The front header is 16-pin and the rear connector is 14-pin.  My apologies.

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I'm pretty sure it is an RGB

I'm pretty sure it is an RGB video card.  The header plugs should have pigtails that go to DB connectors for the video out.  Probably needs to be in slot 7.

 

 

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I knew I’d seen that card

I knew I’d seen that card somewhere. On another site Larry Pell solved the mystery

 

Reference Creative Computing Volume 9, No. 1, January 1983, page 30. The board is an Amdek Digital Video Multiplexer (DVM) for the Apple II to provide RGB output for an Amdek Color-II RGB monitor

The 16 pin connector connected to two circuitboards. One had 4 male plugs that plugged into a group of 4 chip sockets on the II+ motherboard. The other had 2 male plugs that plugged into a pair of chip sockets on the motherboard.

The 14 pin connector was output

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Yes, Amdek DVM card

Thank you, Wayne!  Now that I know that it's an Amtek Digital Video Multiplexer (DVM) card I've been able to find images of it online.  I also found a description of it in the Amdek ad on page  93 of the May, 1982, issue of Call-A.P.P.L.E. Magazine.  Unfortunately I don't have the companion printed circuit boards for it.

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