QBUS RLV12 and the VAX

[Jochen Kunz]

On Wed, 21 Sep 2005 10:02:15 -0500
Patrick Finnegan <pat at computer-refuge.org> wrote:

> The RLV11 doesn't work on a VAX, because it can only do 18-bit 
> addressing, not 22-bit addressing.
Depends on the operating system. NetBSD uses only 18 bit DMA addresing
for both UniBus and QBus. (NetBSD treats UniBus and QBus (nearly) as the
same). Any further addressing is done with the UniBus map / IO-MMU. So
with NetBSD you can use a RLV11. I know this as a RLV11 is mounted in my
VAX 4000-400, driving a RL02. :-)

The problem with the RLV11 is: It is a two card set. It needs two QQ/CD
slots and uses some pins on the QBus for test signals, that are used for
Q22 signals also. I had to open some traces on the board to make it work
in the Q22 VAX.
-- 


tschüß,
       Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/