Strange qbus board

[Roe Peterson]

I received a qbus board with a small pdp11/23 system recently, and I can't find any info about it with my best googling.

It's  made by data systems design, copyright 1980, appears to be model 804120-01. Dual-width qbus board, with a 34-pin ribbon cable connector on the top board edge, maybe floppy controller?

The only real non-ttl non-rom chip is a AM2901BPC.  This seems to be a four-bit bit slice micro...

Anyone ever seen this beastie?

Thanks.