14 May
2016
14 May
'16
5:41 p.m.
From Ed Groenenberg
- insert both CPU cards, KY11-LB card & bootstrap
card, 5 full grant
cards, DL11-W and bus terminator card.
...
- cntrl + boot shows register dump at printer.
...
All looks ok
I'm surprised the bootstrap ran OK with no memory at all in the machine. I
vaguely STR that I had a machine that would not work like that, but maybe I'm
wrong. (DEC bootstaps tend to do things like set the NXM vector, in low
memory, so they can size memory; and when it gets the NXM (since there is no
memory) from trying to touch the NXM vector, and tries to push the old PS and
PC to service _that_, and gets _another_ NXM, that 'double bus fault' often
causes many -11 processors to do a cheap suit)
power down machine, add memory (M7981, 128KW)
What's an M7981? Did you mean an M7891 MS11-L?
- power up machine -> run light is on, does not get
cleared by
cntrl + halt.
This is where a UA11 would really help. I had similar issues with an -11/04,
and the UA11 was a huge help in figuring out what's going on. One glance and
you can see if a bus line is wedged, or something.
- power down & replace memory with grand card
-> run light is off.
Well, that's good sign - the memory card didn't fry anything, at least...
- tried a 2nd memory card (M8722, 128KW)
Ooops. The MS11-M needs +/-12V, which is _not_ standard in most
machines/backplanes). The EUB in the 11/24 and 11/44 (which this card is
intended for) does have it. The really bad part is that those same pins
usually carry +/-15V in most MUD backplanes. So hopefully you didn't fry it.
It does have standard UNIBUS as well as EUB, but there's a jumper, IIRC.
So what could be the problem here? The bus works
without the memory
Two possibilities off the top of my head. i) The first memory card is bad (or
configured incorrectly), or.. ii) The M7891 uses +/-15V as well as +5V? So
maybe one of the other voltages is not so good? But you said the console
worked, and I think that uses other voltages (at least, in EIA mode - not
sure about 20mA, I never touch the stuff).
Noel
14 May
14 May
7:17 p.m.
On 5/14/2016 2:41 PM, Noel Chiappa wrote:
If the bootstrap card is an M9312 with the standard console PROM, it does NOT
require any
memory to be present/accessible to get to the ODT prompt that prints out the
registers and
waits for a command. Only until you execute a device bootstrap command with
'diagnostics
enabled' (the default) does the memory sizing/test/diagnostic code get exectuted.
Listing: http://ak6dn.dyndns.org/PDP-11/M9312/23-248F1/23-248F1.lst
So the system working to this level with no memory present is normal.
Agreed, a bus probe would really be helpful in further debug. Given that the
system does not
even get back to the ODT prompt (which would not yet access memory) indicates
that logic
on the memory card is hanging the bus. Could be a bad bus driver interface chip
(8641, etc).
Bad idea to put this card in an 11/34. As indicated the +12V VDD rail on the
memory chips
is wired directly to the UNIBUS +15V line in the 11/34 (which can be set to +12V
in the 11/44).
So you placed +15V (or more likely up to +15.5V or so) onto the memory chip VDD
lines.
Some 16K chips had a 15V max spec on this pin, others only 13.2V. So it is
possible you
toasted so memory chips, or not, depending on manufacturer and their sensitivity
to OV.
In any event, DO NOT use this card again in the 11/34. It is not compatible with
the backplane.
From Ed
Groenenberg
- insert both CPU cards, KY11-LB card &
bootstrap card, 5 full grant
cards, DL11-W and bus terminator card.
...
- cntrl + boot shows register dump at printer.
...
All looks ok
I'm surprised the bootstrap ran OK with no memory at all in the machine. I
vaguely STR that I had a machine that would not work like that, but maybe I'm
wrong. (DEC bootstaps tend to do things like set the NXM vector, in low
memory, so they can size memory; and when it gets the NXM (since there is no
memory) from trying to touch the NXM vector, and tries to push the old PS and
PC to service _that_, and gets _another_ NXM, that 'double bus fault' often
causes many -11 processors to do a cheap suit) power down machine, add memory (M7981, 128KW)
What's an M7981? Did you mean an M7891 MS11-L?
- power up machine -> run light is on, does
not get cleared by
cntrl + halt.
This is where a UA11 would really help. I had similar issues with an -11/04,
and the UA11 was a huge help in figuring out what's going on. One glance and
you can see if a bus line is wedged, or something. - power down
& replace memory with grand card -> run light is off.
Well, that's good sign - the memory card didn't fry anything, at least...
- tried a 2nd memory card (M8722, 128KW)
Ooops. The MS11-M needs +/-12V, which is _not_ standard in most
machines/backplanes). The EUB in the 11/24 and 11/44 (which this card is
intended for) does have it. The really bad part is that those same pins
usually carry +/-15V in most MUD backplanes. So hopefully you didn't fry it.
It does have standard UNIBUS as well as EUB, but there's a jumper, IIRC. So what could
be the problem here? The bus works without the memory
Two possibilities off the top of my head. i) The first memory card is bad (or
configured incorrectly), or.. ii) The M7891 uses +/-15V as well as +5V? So
maybe one of the other voltages is not so good? But you said the console
worked, and I think that uses other voltages (at least, in EIA mode - not
sure about 20mA, I never touch the stuff).
Noel
15 May
15 May
2:33 a.m.
On Sun, May 15, 2016 01:17, Don North wrote:
Bad idea to put this card in an 11/34. As indicated the +12V VDD rail on
the
memory chips
is wired directly to the UNIBUS +15V line in the 11/34 (which can be set
to +12V
in the 11/44).
So you placed +15V (or more likely up to +15.5V or so) onto the memory
chip VDD
lines.
Some 16K chips had a 15V max spec on this pin, others only 13.2V. So it is
possible you
toasted so memory chips, or not, depending on manufacturer and their
sensitivity
to OV.
I'll label the card as 'possible not working' for a test later in a proper
machine.
On 5/14/2016 2:41 PM, Noel Chiappa wrote:
If the bootstrap card is an M9312 with the standard console PROM, it does
NOT
require any
memory to be present/accessible to get to the ODT prompt that prints out
the
registers and
waits for a command. Only until you execute a device bootstrap command
with
'diagnostics
enabled' (the default) does the memory sizing/test/diagnostic code get
exectuted.
Listing: http://ak6dn.dyndns.org/PDP-11/M9312/23-248F1/23-248F1.lst
So the system working to this level with no memory present is normal.
Agreed, a bus probe would really be helpful in further debug. Given that
the
system does not
even get back to the ODT prompt (which would not yet access memory)
indicates
that logic
on the memory card is hanging the bus. Could be a bad bus driver interface
chip
(8641, etc).
I'll hook up the bus analyzer and see it there is something to see.
From Ed
Groenenberg
- insert both CPU cards, KY11-LB card &
bootstrap card, 5 full
grant
cards, DL11-W and bus terminator card.
...
- cntrl + boot shows register dump at printer.
...
All looks ok
I'm surprised the bootstrap ran OK with no memory at all in the machine.
I
vaguely STR that I had a machine that would not work like that, but
maybe I'm
wrong. (DEC bootstaps tend to do things like set the NXM vector, in low
memory, so they can size memory; and when it gets the NXM (since there
is no
memory) from trying to touch the NXM vector, and tries to push the old
PS and
PC to service _that_, and gets _another_ NXM, that 'double bus fault'
often
causes many -11 processors to do a cheap suit) power down machine, add memory (M7981, 128KW)
What's an M7981? Did you mean an M7891 MS11-L?
- power up machine -> run light is on, does
not get cleared by
cntrl + halt.
This is where a UA11 would really help. I had similar issues with an
-11/04,
and the UA11 was a huge help in figuring out what's going on. One glance
and
you can see if a bus line is wedged, or something. - power down & replace memory with grand card
-> run light is
off.
Well, that's good sign - the memory card didn't fry anything, at
least...
- tried a 2nd memory card (M8722, 128KW)
Ooops. The MS11-M needs +/-12V, which is _not_ standard in most
machines/backplanes). The EUB in the 11/24 and 11/44 (which this card is
intended for) does have it. The really bad part is that those same pins
usually carry +/-15V in most MUD backplanes. So hopefully you didn't fry
it.
It does have standard UNIBUS as well as EUB, but there's a jumper, IIRC. In any event, DO NOT use this card again in the 11/34.
It is not
compatible with
the backplane.
Ed
--
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So what
could be the problem here? The bus works without the
memory
Two possibilities off the top of my head. i) The first memory card is
bad (or
configured incorrectly), or.. ii) The M7891 uses +/-15V as well as +5V?
So
maybe one of the other voltages is not so good? But you said the console
worked, and I think that uses other voltages (at least, in EIA mode -
not
sure about 20mA, I never touch the stuff).
Noel
16 May
16 May
12:13 p.m.
A little progress on the 11/34a
I have a PMK05 (Unibus exerciser) of which I forgot I had it.....
I checked it out first and noticed that the aluminum casting around the
4 slot backplane was broken on both sides. After repairing it by making
2 sleeves of thin copper sheet and a cobblers hammer it became strong
enough to insert the cards again.
After hooking up the PMK05 to the unibus, the machine was powered up
with the memory card, and the 'NPG' led was on.
When done without the memory card, the NPG led stayed off, and others
came on.
The address & data leds changed after depositing a character in
the transmit buffer of the DL11-W.
Pics at www.groenenberg.net/download/PDP11/pic for thos who want to
see the PMK05 in action.
(BTW, the unibus in and out are misprinted on the silkscreen and are
reversed).
BTW2, is there someone who has a manual for it? I only have 2 (xeroxed)
pages of information.
Ed
--
Ik email, dus ik besta.
BTC : 1J5fajt8ptyZ2V1YURj3YJZhe5j3fJVSHN
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15 May
15 May
2:23 a.m.
On Sat, May 14, 2016 23:41, Noel Chiappa wrote:
Could that be done on later models? (i.e. 11/24 and up?)
Yes, a typo, it is a M7891.
Ah, that reminds me, I have an original DEC Unibus analyzer, which is
one of those small suitcase sized boxes and has a display for all
bus signals. Stupid that I didn't think about that.
Ah, well it was not set for EBU mode, but ISTR that there is a jumper
which selects for +12 or +15 volt.
Yes, both +5 and +15 is used and measure ok on the backplane.
From Ed
Groenenberg
- insert both CPU cards, KY11-LB card &
bootstrap card, 5 full grant
cards, DL11-W and bus terminator card.
...
- cntrl + boot shows register dump at printer.
...
All looks ok
I'm surprised the bootstrap ran OK with no memory at all in the machine. I
vaguely STR that I had a machine that would not work like that, but maybe
I'm
wrong. (DEC bootstaps tend to do things like set the NXM vector, in low
memory, so they can size memory; and when it gets the NXM (since there is
no
memory) from trying to touch the NXM vector, and tries to push the old PS
and
PC to service _that_, and gets _another_ NXM, that 'double bus fault'
often
causes many -11 processors to do a cheap suit) power down machine, add memory (M7981, 128KW)
What's an M7981? Did you mean an M7891 MS11-L? - power up machine -> run light is on, does
not get cleared by
cntrl + halt.
This is where a UA11 would really help. I had similar issues with an
-11/04,
and the UA11 was a huge help in figuring out what's going on. One glance
and
you can see if a bus line is wedged, or something. - power down & replace memory with grand card
-> run light is off.
Well, that's good sign - the memory card didn't fry anything, at least...
- tried a 2nd memory card (M8722, 128KW)
Ooops. The MS11-M needs +/-12V, which is _not_ standard in most
machines/backplanes). The EUB in the 11/24 and 11/44 (which this card is
intended for) does have it. The really bad part is that those same pins
usually carry +/-15V in most MUD backplanes. So hopefully you didn't fry
it.
It does have standard UNIBUS as well as EUB, but there's a jumper, IIRC. So what could
be the problem here? The bus works without the memory
Two possibilities off the top of my head. i) The first memory card is bad
(or
configured incorrectly), or.. ii) The M7891 uses +/-15V as well as +5V? So
maybe one of the other voltages is not so good? But you said the console
worked, and I think that uses other voltages (at least, in EIA mode - not
sure about 20mA, I never touch the stuff).
Noel
Ed
--
Ik email, dus ik besta.
BTC : 1J5fajt8ptyZ2V1YURj3YJZhe5j3fJVSHN
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4 comments
3 participants
participants (3)
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ed＠groenenberg.net -
jnc＠mercury.lcs.mit.edu -
north＠alum.mit.edu