27 Jul
2011
27 Jul
'11
12:49 a.m.
On 26/07/2011 15:13, Ethan Dicks wrote:
On Tue, Jul 26, 2011 at 3:41 AM, James Wilson<james
at machineroom.info> wrote:
My only reason for thinking the BDV-11 isn't required is other minimal
systems have been built with similar cards and no BDV (such as
http://www.diane-neisius.de/pdp11/index_E.html). Admitedly, this is in a
different chassis but I wouldn't have thought that would matter, would it?
James
Hi Ethan, are you saying the BDV is required for
a minimal system? My
understanding was I should be able to start ODT without it, since it's built
into the LSI-11 CPU. The CPU also provides the pull-ups for the bus.
The BDV-11 is
bootstrap code and bus terminators, not ODT code. The
CPU provides one end of bus termination. The BDV-11 provides the
other. The backplane does not have any termination of its own (unlike
some enclosures like the BA23).
AFAIK, you will still need the BDV-11 in that last slot.
-ethan