[comp.sys.dec] M7847 16k Unibuss memory questions

Azog-Thoth@cup.portal.com (William Thomas Daugustine) (06/20/91)

About a week or so ago, I posted that I needed help in bringing
my PDP-11/34a back to life. With my description as I know it, the
many people who responded suggested that I had a memory addressing
problem. Better late than never, I looked at it today, and need
help on setting a 16k memory model, so itll live at 0x0000.

In a brilliant flash of ignorance, I stupidly thought, for some reason,
that memory didnt need to live in a specific address range... (majik!)
Anyways, I need some help in setting the DIP switch pack(s) for an 
M7847 module so itll live at the first address, and the first available
CSR (if I need to even set the CSR?). This is going to be the only 16k
module in the machine, I want to bring it up in a minimal configuration
before I go messing with it. I do have 8 other memory boards, for a 
total of 144k, but I dont wish to use these. Eventually, when I can
be sure that the minimum is working, Ill put in a 128kw memory module,
and free up that many slots (even free up a whole backplane! 9 modules,
9 slots!)

Thanx 

Billy D'Augustine
Azog-Thoth@cup.portal.com

PS: in a side question: what is the model number of the Floating Point
Unit thatll run in an 11/34a? And does it need to live in a specific
slot, such as the next slot from the main processor cards? 

terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr.) (06/21/91)

In article <43481@cup.portal.com>, Azog-Thoth@cup.portal.com (William Thomas Daugustine) writes:
> 
> About a week or so ago, I posted that I needed help in bringing
> my PDP-11/34a back to life. With my description as I know it, the
> many people who responded suggested that I had a memory addressing
> problem. Better late than never, I looked at it today, and need
> help on setting a 16k memory model, so itll live at 0x0000.

  You should have an MS11-J module. In the future, please give the Mxxxx
suffix (usually on the next lower handle "rib" from the M-number.

  That board should have jumpers W1-W2, W3-W4, and W5-W6 inserted. If
not, it's not an MS11-J module. The switch settings for memory at 0
are:

SW A-C off, SW D-E on, SW F off, SW H on, SW J off (the last three are
for I/O page stuff).

> In a brilliant flash of ignorance, I stupidly thought, for some reason,
> that memory didnt need to live in a specific address range... (majik!)

  True on almost all VAXen. Not true (as you've discovered) on most PDP-11's.

> PS: in a side question: what is the model number of the Floating Point
> Unit thatll run in an 11/34a? And does it need to live in a specific
> slot, such as the next slot from the main processor cards? 

  FP11-A (M8267). Yes, it has a dedicated slot and (I think) a ribbon cable.
Be sure you have a 34A (M8265/M8266) and not a 34 (M7265/M7266) first...

	Terry Kennedy		Operations Manager, Academic Computing
	terry@spcvxa.bitnet	St. Peter's College, US
	terry@spcvxa.spc.edu	(201) 915-9381