Baydel Unibus disk systems

Mike Ross tmfdmike at
Fri Mar 18 21:26:47 CDT 2016


I've found something I forgot I had; a Baydel Unibus disk controller.
At one time I had 3 or 4 of these in complete systems but carelessly
managed to trade them all away(!) - except this one board.

They were all identical; a pdp-11/04 with a quad Unibus Baydel disk
controller hooked up to an 8" hard drive in a separate rack mount. In
use the Baydel subsystem emulated multiple RK05s.

The part number on the board is B01061. Unusually Google seems to be
utterly silent on the subject; it seems Baydel and these products have
slipped beneath the digital waves without trace. Does anyone have any

I just have the controller board; I don't have any of the hard drives
left. All I remember is the disk was an 8" and the interface is a
single 40-pin cable; so not SMD and not SCSI. Far too early for IDE or
ATA. Any suggestions for what the interface might have been and what
disks might have been used? What hard disks were around in late 70s /
early 80s that used a single 40-pin connector??


'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'

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