8 Jan
2009
8 Jan
'09
8:42 p.m.
On 08/01/2009 15:25, Bob Armstrong wrote:
> Pete Turnbull (pete at dunnington.plus.com)
wrote:
> a 64KB (32KW) MSV11-D with a base address of 000000(8) responds to all
> addresses from 000000(8) to 177777(8).
It's certainly possible that could be a problem,
but I've been reading the
MSV11-D user's manual (it's on vt100.net) and it doesn't have a jumper to
disable the top page. Actually what it has is a jumper to _enable_ the
bottom 2K of the I/O page, so you can have a tiny bit of extra RAM in
systems without many I/O devices.
Ah yes, I mis-remembered - sorry. All the diagrams and labels in the
MSV11-D,E manuals and the various handbooks refer to that jumper as
"enable/disable bank 7" and I tend to forget exactly what that means!
The MSV11 manual says only "factory configured
modules will not respond to
bank 7 addresses..." and it then goes on to say how you can enable the lower
2K of bank 7 with the aforementioned jumper, but it's quiet about how it
decides what a bank 7 address is (i.e. does it monitor BBS7 or the address
bits?).
It monitors BBS7 to determine if access is to the I/O page, and
optionally combines that with BDAL12 to see if it's the lower 2K or
upper 2K.
If you jumper the CPU to enter ODT instead of executing the bootstrap,
what happens? Or if you power things up with with the front panel set
to HALT? If you attempt to execute the BDV11 bootstrap, what happens
when it halts? Does the RUN light ever light, even briefly? What do
the lights on the BDV11 show?
Do these same boards, in exactly this combination, work properly in the
BA11-M? Exactly which version of the M7264 do you have?
--
Pete Peter Turnbull
Network Manager
University of York