[net.periphs] Inexpensive Q-bus disk systems

droms@purdue.UUCP (Ralph E. Droms) (03/24/86)

I'm looking for information about inexpensive Q-bus compatible hard disk
systems.  I'm willing to put together a system out of components, to take
advantage of the falling prices of 10-50Mb drives and controllers.  I
imagine the expensive component in a Q-bus disk system will be the
Q-bus<=>controller interface.  Any information or other leads will be
greatly appreciated.

					- Ralph

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==================================================================
Ralph Droms					ihnp4!purdue!droms
CS G73						droms@purdue.edu
Dept. of Computer Sciences			droms@purdue.csnet
Purdue University
West Lafayette, IN 47907

keith@reed.UUCP (Keith Packard) (04/29/86)

In article <541@mordred.purdue.UUCP> droms@purdue.UUCP (Ralph E. Droms) writes:
>I'm looking for information about inexpensive Q-bus compatible hard disk
>systems.  I'm willing to put together a system out of components, to take
>advantage of the falling prices of 10-50Mb drives and controllers.  I
>imagine the expensive component in a Q-bus disk system will be the
>Q-bus<=>controller interface.  Any information or other leads will be
>greatly appreciated.
>

The cheapest Q-bus disk system I have ever built is:

	DTC 11-1	Q-bus SCSI adaptor	~$250
	Adaptec ACB4070	SCSI ST506 card		~$220

I've also written pdp11 2.9 disk drivers for this set up - it's not 
pleasent but it is reasonably fast (interleave of 2) and very cheap.

Oh, added bennies of the ACB4070 board is that it uses something other
than MFM format on the disk and gives you 26 1K byte sectors per track -
about 50% increase in disk capacity

	Keith Packard
	...!tektronix!reed!keith