[net.unix-wizards] mixing 256k & 1M memory boards

peter@hp-pcd.UUCP (07/20/83)

#N:hp-pcd:19500001:000:606
hp-pcd!peter    Jul 19 12:26:00 1983

We have heard conflicting testimony on whether or not you can mix the old-style
DEC 256k memory boards with the new DEC 1M memory boards in the same VAX-750
CPU under 4.1bsd (given new controller and backplane, of course).

Some sources say it is a simple jumper change (explained in DEC documentation),
but DEC sales says it cannot be done.

We would appreciate comments from anyone who has actually done it or someone
who has hard evidence that it cannot be done.


					    Thanks,

					    Brian Phillips

				...ucbvax!hplabs!hp-pcd!brian
					...harpo!hp-pcd!brian
				       ...ogcvax!hp-pcd!brian

ra@rlgvax.UUCP (Rick Adams) (07/21/83)

Both National Semi and Trendata/Standard say that their current 256k
memory boards are incompatible. This coupled with same statement from
the local DEC rep seems pretty definite to me.

National claims to have prototypes available in September with
production boards in early 1984. Trendata/Standard  is willing to ship
you a Beta test (their term) board immediately with no promises.

We don't have our new vax (780 if it matters) yet, so I have no actual
hands on experience, but the fact that the DEC compatible vendors won't
sell you working boards sort of forces you to go with DEC memory.

Rick Adams
CCI Office Systems Group
Reston, VA 
{allegra|seismo|ihnp4|mcnc}!rlgvax!ra