29 Apr
2015
29 Apr
'15
9:13 p.m.
On 4/29/15 5:14 PM, Don North wrote:
I'm now running off of a M9312, and there is a TU-58 boot PROM for that
(see here: http://ak6dn.dyndns.org/PDP-11/M9312/). I believe I have
a set
of compatible PROMs and I'll probably try that tonight, if I can find
the
time (and the DL11 :)).
The 'ZZ' (my notation) for the M9312 is also a useful addition for
debug/sanity checking.
It goes in like a device prom, but just runs the simple M9312 console
diagnostics and low
memory (28KW or less) memory test continuously. Image available on the
link to my website
above, or contact me directly and I can provide a preprogrammed
device. Same for the TU58
(or other) boot proms. Cool, thanks! I'll let you know if I have need of your
services :).
- Josh
On 4/29/2015 4:11 PM, Josh Dersch wrote:
Here's the official word, straight from the 11/34 user's manual on
Bitsavers (Page 4-20):
"NOTE
In boxes other than the BA11-L, there is not sufficient drive capability
on the LTC L signal to
drive multiple loads. Since each DL11-W constitutes a load (even if the
line clock is disabled
by the switch), multiple DLL11-Ws in a box will overload the LTC L
signal causing line clock failures.
To alleviate the loading effect of the additional DL11-Ws, remove the
resistor R64 from all DL11-W
modules except the one being used as line clock. If multiple DL11-Ws
are used on the same system,
the line clock must be enabled (via switches) only on thee DL11-W being
used as a line clock."
I found my spare SLU, and it's a DL11-W, and I have a BA11-K. I'll see
if I run into issues, and if so I'll pull the resistor
On Wed, Apr 29, 2015 at 3:58 PM, Noel Chiappa
<jnc at mercury.lcs.mit.edu>
wrote:
That's good to know, thanks. I do have a spare DL11 in my stash of
spare
boards, I just need to find it, it appears to have gotten misplaced
during
my house move last year. Not sure if it's a -W or not.
I've had two DL11-W in my 11/34A BA11-K box for years and have never
had an LTC issue.
I suppose if you had a a larger number (say four or more) you might
possibly see an LTC
issue, but I never have with just two. In any event you could
completely disconnect the
LTC circuitry on the DL11-W by removing just one inline series resistor. From:
Jorg Hoppe
I also have a spare DL11-W to offer
Josh, if you want a second serial line, it's best to use a regular DL11
(M7800), not a DL11-W. (M7800s are available on eBay, for pretty modest
amounts.) The reason is that each DL11-W presents a load on the line
clock
signal (from the power supply), even if the line clock on the second
board
is
disabled; several Dl11-W's, and the line clock signal may get
overloaded.
From: Josh Dersch
I need to scare up a second SLU so I can get an
emulated
TU-58 hooked
up to try booting XXDP
I'm not sure any M9301 variant supports the TU-58? Some are set up
to boot
over the console serial line, though. (I haven't yet checked the
code, so I
don't know whether you need to feed it the absolute loader first, or
if it
will just take .LDA files directly.)
Don