11 Jan
2019
11 Jan
'19
2:32 p.m.
From: Allison Parent
Most Probable cause is interrupt grant is broken.
The only -11 that complains if the grant chain is broken that I know of is
the /34 (maybe the /04 too). I certainly have a QBUS chassis right next to my
workstation here that i) has a bunch of empty slots, and ii) works fine, as
long as there are no empty slots between the CPU and the devices.
Also, IIRC he said it works with 3 cards plugged in, but not 4; how can
plugging a card _in_ cause grant problems?
For most microspheres backplanes the first three slots
are different
than remaining.
That might be worth checking into. I'm not familiar with the second box
he's using, so can't help there.
Noel
11 Jan
11 Jan
2:59 p.m.
On 1/11/19 2:32 PM, Noel Chiappa via cctalk wrote:
MicroPDP box has first three slots A-B-C-D to support PMI
memory and the rest are serpentine A-B.
Even giving a bus grant problem, I can't see that causing a CSR
error. I will probably have to dig out another box this weekend
just to be sure there isn't a problem with the backplane.
bill
From: Allison
Parent
Most Probable cause is interrupt grant is broken.
The only -11 that complains if the grant chain is broken that I know of is
the /34 (maybe the /04 too). I certainly have a QBUS chassis right next to my
workstation here that i) has a bunch of empty slots, and ii) works fine, as
long as there are no empty slots between the CPU and the devices.
Also, IIRC he said it works with 3 cards plugged in, but not 4; how can
plugging a card _in_ cause grant problems?
For most microspheres backplanes the first three
slots are different
than remaining.
That might be worth checking into. I'm not familiar with the second box
he's using, so can't help there. 
3:38 p.m.
On 11/01/2019 19:59, Bill Gunshannon via cctalk wrote:
MicroPDP box has first three slots A-B-C-D to support
PMI
memory and the rest are serpentine A-B.
Even giving a bus grant problem, I can't see that causing a CSR
error. I will probably have to dig out another box this weekend
just to be sure there isn't a problem with the backplane.
Without knowing exactly what cards you've got in there, it's hard to
tell. There are quad-height cards that work only in straight (A.B.C.D)
backplanes/slots, and quad cards that work in either straight or
serpentine. There are cards that use or expect (or won't permit) certain
signals on some pins which work fine in 18-bit backplanes but not
22-bit. There are things that will work in a BA11-S with H9276
backplane (which is what you had, if it really was a PDP-11/23plus) but
not a BA23. You probably need to make a list of what you're using and
check through the relevant Micronotes about compatibility.
BTW, BA23 and BA123 microPDP-11 backplanes aren't the same - it's the
first 4 slots that differ in a BA123, and slot 13 is different again.
Take a look at http://www.dunnington.info/public/PDP-11/QBus_chassis
--
Pete
Pete Turnbull
3:51 p.m.
On 1/11/19 3:38 PM, Pete Turnbull via cctalk wrote:
On 11/01/2019 19:59, Bill Gunshannon via cctalk
wrote:
Listed what I'm using in the beginning of this thread.
Just CPU and Memory at this point. Will add disk and
network when I get this part working.
MicroPDP box has first three slots A-B-C-D to
support PMI
memory and the rest are serpentine A-B.
Even giving a bus grant problem, I can't see that causing a CSR
error.? I will probably have to dig out another box this weekend
just to be sure there isn't a problem with the backplane.
Without knowing exactly what cards you've got in there, it's hard to
tell.? There are quad-height cards that work only in straight (A.B.C.D)
backplanes/slots, and quad cards that work in either straight or
serpentine. There are cards that use or expect (or won't permit) certain
signals on some pins which work fine in 18-bit backplanes but not
22-bit.? There are things that will work in a BA11-S with H9276
backplane (which is what you had, if it really was a PDP-11/23plus) but
not a BA23.? You probably need to make a list of what you're using and
check through the relevant Micronotes about compatibility.
BTW, BA23 and BA123 microPDP-11 backplanes aren't the same - it's the
first 4 slots that differ in a BA123, and slot 13 is different again.
Take a look at http://www.dunnington.info/public/PDP-11/QBus_chassis
Mine are all BA23. Wasn't the BA123 for the MicroVAX?
bill
4:34 p.m.
On 11/01/2019 20:51, Bill Gunshannon via cctalk wrote:
Listed what I'm using in the beginning of this
thread.
Just CPU and Memory at this point.
OK, I didn't see that - sorry.
> BTW, BA23 and BA123 microPDP-11 backplanes
aren't the same - it's the
> first 4 slots that differ in a BA123, and slot 13 is different again.
> Take a look at http://www.dunnington.info/public/PDP-11/QBus_chassis
Mine are all BA23. Wasn't the BA123 for the
MicroVAX?
No, it was introduced for the microPDP-11 series, and only later used
for MicroVAX and MicroVAX-II. There are many microPDP-11/83 machines in
BA123 cabinets, it was a very popular option because of the space for
storage devices and the extra backplane slots.
--
Pete
Pete Turnbull
6:59 p.m.
On Fri, Jan 11, 2019 at 4:39 PM Pete Turnbull via cctalk
<cctalk at classiccmp.org> wrote:
Hmm... I did not know they put the 11/83 in a BA123. It makes sense
since, as you say, there's room for storage devices and plenty of
slots.
The first BA123 system I ever saw was a KA630/uVAX-II in 1986. We put
Ultrix T-2.0 on it and ran it for several years.
-ethan
Mine are all
BA23. Wasn't the BA123 for the MicroVAX?
No, it was introduced for the microPDP-11 series, and only later used
for MicroVAX and MicroVAX-II. There are many microPDP-11/83 machines in
BA123 cabinets, it was a very popular option because of the space for
storage devices and the extra backplane slots. 
7:11 p.m.
On 11 Jan 2019, at 23:59, Ethan Dicks via cctalk
<cctalk at classiccmp.org> wrote:
On Fri, Jan 11, 2019 at 4:39 PM Pete Turnbull via cctalk
<cctalk at classiccmp.org> wrote:
Hmm... I did not know they put the 11/83 in a BA123. It makes sense
since, as you say, there's room for storage devices and plenty of
slots.
It?s going back severalteen years now but I?m pretty sure I built a Micro 73 into a BA123,
it?s a CD22 backplane after all. I still have all the cards AND the BA123 but I?m supposed
to be turning it back into the MVII it was originally, back in 1986 when it was called
FRUIT.
--
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaurs f: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk
Mine are
all BA23. Wasn't the BA123 for the MicroVAX?
No, it was introduced for the microPDP-11 series, and only later used
for MicroVAX and MicroVAX-II. There are many microPDP-11/83 machines in
BA123 cabinets, it was a very popular option because of the space for
storage devices and the extra backplane slots.
7:55 p.m.
On Fri, Jan 11, 2019 at 7:11 PM Adrian Graham via cctalk
<cctalk at classiccmp.org> wrote:
It?s going back severalteen years now but I?m pretty
sure I built a Micro 73 into a BA123, it?s a CD22 backplane after all. I still have all
the cards AND the BA123 but I?m supposed to be turning it back into the MVII it was
originally, back in 1986 when it was called FRUIT.
It will definitely work, but I just wasn't sure about what types of
CPUs _DEC_ stuffed into a BA123 and sold out the front door.
-ethan
8:24 p.m.
On Jan 11, 2019, at 4:55 PM, Ethan Dicks via cctalk
<cctalk at classiccmp.org> wrote:
On Fri, Jan 11, 2019 at 7:11 PM Adrian Graham via cctalk
<cctalk at classiccmp.org> wrote:
My /73 was originally a MicroVAX II at Tektronix. After I got it, I turned it into a
PDP-11 after getting a VAXstation 3100.
I?m pretty sure you could get the /23+, /53, /73, /83, and /93 in either a BA23 or a
BA123. I have an actual badged BA23 pedestal for my /23+.
Zane
It?s going back severalteen years now but I?m
pretty sure I built a Micro 73 into a BA123, it?s a CD22 backplane after all. I still have
all the cards AND the BA123 but I?m supposed to be turning it back into the MVII it was
originally, back in 1986 when it was called FRUIT.
It will definitely work, but I just wasn't sure about what types of
CPUs _DEC_ stuffed into a BA123 and sold out the front door.
-ethan 
8:56 p.m.
On Fri, Jan 11, 2019 at 6:24 PM Zane Healy via cctalk <cctalk at classiccmp.org>
wrote:
Not sure about the /53, but I've seen /73s and /83s in BA23 for sure, and a
/83s in BA123. Our VAXstation II was in a BA23 we converted to rack mount,
and I've seen lots of MicroVAX IIs in BA123 cases.
Warner
On Jan 11, 2019, at 4:55 PM, Ethan Dicks via
cctalk <
cctalk at classiccmp.org> wrote:
On Fri, Jan 11, 2019 at 7:11 PM Adrian Graham via cctalk
<cctalk at classiccmp.org> wrote:
> It?s going back severalteen years now but I?m pretty sure I built a
Micro 73
into a BA123, it?s a CD22 backplane after all. I still have all
the cards AND the BA123 but I?m supposed to be turning it back into the
MVII it was originally, back in 1986 when it was called FRUIT.
It will definitely work, but I just wasn't sure about what types of
CPUs _DEC_ stuffed into a BA123 and sold out the front door.
-ethan
My /73 was originally a MicroVAX II at Tektronix. After I got it, I
turned it into a PDP-11 after getting a VAXstation 3100.
I?m pretty sure you could get the /23+, /53, /73, /83, and /93 in either a
BA23 or a BA123. I have an actual badged BA23 pedestal for my /23+.
12 Jan
12 Jan
9:20 a.m.
Well, the problem is definitely bus grant as with just two memory
cards in the machine I put the disk controller in and it does not
show up in the Map. The only problem with this is the question
Why? I have examined the memory cards. The C-D (actually, C)
does have the bus grant lines connected. I even looked under a
magnifier to be sure the trace hadn't been cut and it is intact.
So, what else cold cause this?
(Another question, however, some cards have the ability to open
this. Why would you ever do that as it would break pretty much
any card that followed?)
bill
12:31 p.m.
On 1/12/19 9:20 AM, Bill Gunshannon via cctalk wrote:
Well, the problem is definitely bus grant as with just two memory
cards in the machine I put the disk controller in and it does not
show up in the Map. The only problem with this is the question
Why? I have examined the memory cards. The C-D (actually, C)
does have the bus grant lines connected. I even looked under a
magnifier to be sure the trace hadn't been cut and it is intact.
So, what else cold cause this?
(Another question, however, some cards have the ability to open
this. Why would you ever do that as it would break pretty much
any card that followed?)
Problem fixed. Note, fixed, not solved.
I dug out another MicroPDP BA23 box. Stuck the CPU in slot 1.
Started adding the memory cards one at a time and turning the
machine on waiting for the self-test and then doing a MAP.
Worked perfectly. The self test got slower as each memory
card was added and the map showed the block of memory and the
assigned CSR.
So, what could go bad on a backplane to cause this problem?
Or, could it be a power supply that is no longer delivering
the rated power?
In any event, I, at least now, have two functional systems.
an 11/93 with 2 meg of memory (which might be expandable
with PMI but definitely not with QBUS memory.) And an
11/73 with 4 meg of QBUS memory which apparently could be
an 11/83 if I had 4 meg of PMI memory.
Anybody got any PMI memory they would be willing to let go? :-)
bill
12:44 p.m.
On 1/12/19 11:31 AM, Bill Gunshannon via cctalk wrote:
On 1/12/19 9:20 AM, Bill Gunshannon via cctalk wrote:
Congrats on getting this part of the problem resolved.
Well, the problem is definitely bus grant as with just two memory
cards in the machine I put the disk controller in and it does not
show up in the Map. The only problem with this is the question
Why? I have examined the memory cards. The C-D (actually, C)
does have the bus grant lines connected. I even looked under a
magnifier to be sure the trace hadn't been cut and it is intact.
So, what else cold cause this?
(Another question, however, some cards have the ability to open
this. Why would you ever do that as it would break pretty much
any card that followed?)
Problem fixed. Note, fixed, not solved.
I dug out another MicroPDP BA23 box. Stuck the CPU in slot 1.
Started adding the memory cards one at a time and turning the
machine on waiting for the self-test and then doing a MAP.
Worked perfectly. The self test got slower as each memory
card was added and the map showed the block of memory and the
assigned CSR. So, what could go bad on a backplane to cause this
problem?
Or, could it be a power supply that is no longer delivering
the rated power?
If you haven't already, check the backplane slots for debris or corrosion on the
contacts.
Next with a voltmeter check the +5V and +12V first to see if the actual voltages are
within spec. If you have an oscilloscope, checking for excess voltage ripple. If the
power supplies have are using the original capacitors they might not be providing clean
power under significant load.
? Jerry
12:29 p.m.
On 12/01/2019 01:24, Zane Healy via cctalk wrote:
I?m pretty sure you could get the /23+, /53, /73, /83,
and /93 in either a BA23 or a BA123. I have an actual badged BA23 pedestal for my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down 11/53
were as well. But almost all the 11/83 systems I've ever seen were in
BA123 boxes, though they did sell some in BA23 pedestals - I've got one.
--
Pete
Pete Turnbull
12:39 p.m.
On 1/12/19 12:29 PM, Pete Turnbull via cctalk wrote:
On 12/01/2019 01:24, Zane Healy via cctalk wrote:
One confusing part of this. Everything I have read today
seems to say that the only difference between the 11/73
and the 11/83 in a MicroPDP-11 was the memory used.
QBUS = 11/73
PMI = 11/83
Is this correct or not?
bill
I?m pretty sure you could get the /23+, /53, /73,
/83, and /93 in
either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down 11/53
were as well.? But almost all the 11/83 systems I've ever seen were in
BA123 boxes, though they did sell some in BA23 pedestals - I've got one.
1:13 p.m.
On 1/12/19 11:39 AM, Bill Gunshannon via cctalk wrote:
On 1/12/19 12:29 PM, Pete Turnbull via cctalk wrote:
I use this guide in general -
http://web.frainresearch.org:8080/projects/pdp-11/dcj11.php to
understand the key differences in DEC DCJ11 implementations. You can see
how the clock speed, caching and memory type drove differences in
performance and marketing labels.
The 11/83 (M8190-AD or AE) with Non-PMI memory is just a slow 11/83 in
my view. I know RT11 did report it as an 11/73.?? It could be that from
a software perspective, RT11 might not be possible to determine the
actual module in use.
Does the 2MB 11/93 not work with and extra 2Mb of QBUS Non-PMI memory??
I would have thought the upper 2MB would still be addressable, if for
nothing else than for compatibility memory mapped display controllers
and such.
?? Jerry
On 12/01/2019 01:24, Zane Healy via cctalk
wrote:
One confusing part of this. Everything I have read today
seems to say that the only difference between the 11/73
and the 11/83 in a MicroPDP-11 was the memory used.
QBUS = 11/73
PMI = 11/83
I?m pretty sure you could get the /23+, /53, /73,
/83, and /93 in
either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in
BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down 11/53
were as well.? But almost all the 11/83 systems I've ever seen were in
BA123 boxes, though they did sell some in BA23 pedestals - I've got one.
1:23 p.m.
On 1/12/19 1:13 PM, Jerry Weiss wrote:
On 1/12/19 11:39 AM, Bill Gunshannon via cctalk
wrote:
I always thought it was an 11/73. It wasn't until the last few days
that I saw the difference mentioned. It works fine as an 11/73 and
having PMI memory and making it an 11/83 would just be for fun anyway.
I have run Ultrix-11 on 11/73's with no real problems.
On 1/12/19 12:29 PM, Pete Turnbull via cctalk
wrote:
I use this guide in general -
http://web.frainresearch.org:8080/projects/pdp-11/dcj11.php to
understand the key differences in DEC DCJ11 implementations. You can see
how the clock speed, caching and memory type drove differences in
performance and marketing labels.
The 11/83 (M8190-AD or AE) with Non-PMI memory is just a slow 11/83 in
my view. I know RT11 did report it as an 11/73.?? It could be that from
a software perspective, RT11 might not be possible to determine the
actual module in use. On 12/01/2019 01:24, Zane Healy via cctalk
wrote:
One confusing part of this. Everything I have read today
seems to say that the only difference between the 11/73
and the 11/83 in a MicroPDP-11 was the memory used.
QBUS = 11/73
PMI = 11/83
I?m pretty sure you could get the /23+, /53, /73,
/83, and /93 in
either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in
BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down 11/53
were as well.? But almost all the 11/83 systems I've ever seen were in
BA123 boxes, though they did sell some in BA23 pedestals - I've got one.
Does the 2MB 11/93 not work with and extra 2Mb of QBUS Non-PMI memory?
I would have thought the upper 2MB would still be addressable, if for
nothing else than for compatibility memory mapped display controllers
and such.
I had tried it and, no, it didn't work. I then had people tell me
it wouldn't. I have also been told the only way to upgrade is to
add the missing memory onto the CPU board. I find that hard to
believe, but I suppose it is possible. I am not sure I could do
that upgrade as some of the chips are surface mount. Not that it
matters as a search could not turn up any supply for those particular
memory chips. But, if I came up with a 2 meg or pair of 1 meg PMI
boards I would definitely try it. :-) Just like the 11/73|11/83
deal. If a 4 meg PMI card fell in my lap I would definitely try
it to see if there was a difference. Matter of fact, I would likely
find some benchmarks I could run under Ultrix-11 and see what the
actual difference was. But, it's all academic cause I really don't
see any PMI memory falling from the sky and I haven't seen any pigs
fly by lately. :-)
bill
1:31 p.m.
On 12/01/2019 17:39, Bill Gunshannon via cctalk wrote:
One confusing part of this. Everything I have read
today
seems to say that the only difference between the 11/73
and the 11/83 in a MicroPDP-11 was the memory used.
QBUS = 11/73
PMI = 11/83
Is this correct or not?
No, not really, but sort of. Originally, the J11 chip was available in
15MHz and 18MHz versions. The 15MHz chips were used for 11/73 systems
and the 18MHz ones for 11/83 systesm. To emphasise the difference, they
had slightly different boot ROMs, and the 11/73 systems were shipped
with QBus memory while the 11/83 systems were shipped with PMI memory,
which is faster. So a factory-fresh 11/73 was always 15MHZ + QBus
memory, whereas a factory-fresh 11/83 was always 18MHz with PMI memory,
and significantly faster. In fact the PDP-11 and Hardware Help lists on
DECUServe were full of people discussing the difference as many people
didn't believe that you could use PMI memory with the processor from an
11/73 (you can), while others insisted that if you changed the memory an
11/73 became exactly an 11/83. In fact the XXDP diagnostics and RT-11
differentiate 11/73 from 11/83 purely on the basis of PMI memory detection.
The J11 chip used on those systems was supposed to run at 20MHz or so
from day one, but it didn't quite make it. Some,
especially early on,
would only run fully reliably at 15MHz, hence the above.
I've got a
later one in an 11/83 running at 20MHz, though. It doesn't gain an
awful lot, but I changed the crystal, just because I could.
--
Pete
Pete Turnbull
2:25 p.m.
On 01/12/2019 12:29 PM, Pete Turnbull via cctalk wrote:
On 12/01/2019 01:24, Zane Healy via cctalk wrote:
Pete,
Your right the 11/23+ showed up on a lot of boxes but not the BA123
though it would fit.? The? BA23 as the micropdp11 or 11/53..? names and
models were a large jumble.? The J11 based CPU were showing up int BA123
as the later ones had PMI and a natural for the 123 as anyone
using J11 likely wanted storage, memory and space for it.??
Not not all of the dual width 11/73s were slow chips only that the were
run at 15mhz.? No advantage for faster as Qbus transactions
are slower for memory so the PMI versions were faster by default.
My BA23 (micropdp11was upgraded to microVAXII by me before DEC left me
and the machine next to it under the desk was VIDSYS: a
MicrovaxII GPX They both came home with me on last day.?? The BA23 was
put back to the micropdp11 config and VIDSYS: remains though
with larger disks.? I also have a rack based system (11/73 CPU) and
multiple BA11 series mostly 11/23(various flavors) based but have the
11/2 board and LSI-11.?? Even An H11 backplane with LSI-11 and Heath ram
and IO.
While there were many sold systems and a larger number of supported
systems Qbus PDP-11 was more mix and match than most any
and the early Qbus microVAX series did that for a while.?
Allison
I?m pretty sure you could get the /23+, /53, /73,
/83, and /93 in
either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down
11/53 were as well.? But almost all the 11/83 systems I've ever seen
were in BA123 boxes, though they did sell some in BA23 pedestals -
I've got one.
4:14 p.m.
On 1/12/19 2:25 PM, allison via cctalk wrote:
On 01/12/2019 12:29 PM, Pete Turnbull via cctalk
wrote:
My 11/23+ is in a box labeled PDP-11/23PLUS on the front with
three toggle switches. :-) It has a 9276-A backplane labeled
OPTION 11/23B. It is a 9 slot, Q22 A-B-C-D . That's the home
for my next system which will (hopefully) have 2 meg of memory,
a DEQNA and an Andromeda Card for a small hard disk and 8" floppy.
I also plan on another small 11/23 with 128KW of memory and an
18 bit backplane so I can use the RX02 emulator. And, probably
an Andromeda in there, too
To bring my part of this discussion to an end, I now have a BA23
MicroPDP box with an 11/73 CPU, 4 meg of memory, DHV11 for eight
serial lines (probably only use one to talk to a TU58 emulator
but the DHV11 was just sitting there looking lonely) a DEQNA
and a CMD SCSI Controller set for 6 disks and one tape. Only
thing it lacks at this point is software.
On to my next project.
Thanks for all the help. I had forgotten just how much fun
real computers were compared to PC's and MAC's.
bill
On 12/01/2019 01:24, Zane Healy via cctalk
wrote:
Pete,
Your right the 11/23+ showed up on a lot of boxes but not the BA123
though it would fit. I?m pretty sure you could get the /23+, /53, /73,
/83, and /93 in
either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down
11/53 were as well.? But almost all the 11/83 systems I've ever seen
were in BA123 boxes, though they did sell some in BA23 pedestals -
I've got one.
4:30 p.m.
On 01/12/2019 04:14 PM, Bill Gunshannon via cctalk wrote:
On 1/12/19 2:25 PM, allison via cctalk wrote:
BA11 box
with one of the usual two common backplanes or standard BA23.
Problem with DEQNA is what OS?? RT11 does nothing with it.? RSX-11
I don't have a recent enough version so its often unused/
On 01/12/2019 12:29 PM, Pete Turnbull via cctalk
wrote:
My 11/23+ is in a box labeled PDP-11/23PLUS on the front
with
three toggle switches. :-) It has a 9276-A backplane labeled
OPTION 11/23B. It is a 9 slot, Q22 A-B-C-D . That's the home
for my next system which will (hopefully) have 2 meg of memory,
a DEQNA and an Andromeda Card for a small hard disk and 8" floppy. On 12/01/2019 01:24, Zane Healy via cctalk
wrote:
Pete,
Your right the 11/23+ showed up on a lot of boxes but not the BA123
though it would fit. I?m pretty sure you could get the /23+, /53, /73,
/83, and /93 in
either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in
BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down
11/53 were as well.? But almost all the 11/83 systems I've ever seen
were in BA123 boxes, though they did sell some in BA23 pedestals -
I've got one.
I also plan on another small 11/23 with 128KW of
memory and an
18 bit backplane so I can use the RX02 emulator. And, probably
an Andromeda in there, too
To bring my part of this discussion to an end, I now have a BA23
MicroPDP box with an 11/73 CPU, 4 meg of memory, DHV11 for eight
serial lines (probably only use one to talk to a TU58 emulator
but the DHV11 was just sitting there looking lonely) a DEQNA
and a CMD SCSI Controller set for 6 disks and one tape. Only
thing it lacks at this point is software.
The TU58 like a responsive IO a DLV11J is
a better choice for console and DD
and works best if first card after the memory (early in the interrupt
grant chain).
The simulators are faster than tu58 so it makes for fewer retries.
I use DHV11 for terminal and modem lines (slower stuff).
On to my next project.
Thanks for all the help. I had forgotten just how much fun
real computers were compared to PC's and MAC's.
Yes they are.? Their
performance without all the gui gunk is often a
suprize
to many that have not worked with them.
Allison
bill
5:03 p.m.
On 1/12/19 4:30 PM, allison via cctalk wrote:
My 11/73 only has a console, thus the need for the DHV11 but really
only one port. (Although I may try putting multiple serial ports in
all the boxes and doing some "networking" over them. :-)
On 01/12/2019 04:14 PM, Bill Gunshannon via cctalk
wrote:
My only problem is I have 3 DEQNA and 1 DELQA. I thought I read
somewhere recently that the DEQNA was the better of the two.
As for software, what about the Kent TCPIP package? Will that
not work with the DEQNA? I thought the two Ethernet controllers
for QBUS were functionally the same.
And, while we are at it, if I type BOOT XH does it look for a
MOP Server?
On 1/12/19 2:25 PM, allison via cctalk wrote:
BA11 box
with one of the usual two common backplanes or standard BA23.
Problem with DEQNA is what OS?? RT11 does nothing with it.? RSX-11
I don't have a recent enough version so its often unused/ On 01/12/2019 12:29 PM, Pete Turnbull via cctalk
wrote:
My 11/23+ is in a box labeled PDP-11/23PLUS on the front
with
three toggle switches. :-) It has a 9276-A backplane labeled
OPTION 11/23B. It is a 9 slot, Q22 A-B-C-D . That's the home
for my next system which will (hopefully) have 2 meg of memory,
a DEQNA and an Andromeda Card for a small hard disk and 8" floppy. On 12/01/2019 01:24, Zane Healy via cctalk
wrote:
> I?m pretty sure you could get the /23+, /53, /73, /83, and /93 in
> either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
> my /23+.
I'm fairly certain all microPDP-11/23+ systems were only sold in BA23
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down
11/53 were as well.? But almost all the 11/83 systems I've ever seen
were in BA123 boxes, though they did sell some in BA23 pedestals -
I've got one.
Pete,
Your right the 11/23+ showed up on a lot of boxes but not the BA123
though it would fit. I also plan on another small 11/23 with 128KW of
memory and an
18 bit backplane so I can use the RX02 emulator. And, probably
an Andromeda in there, too
To bring my part of this discussion to an end, I now have a BA23
MicroPDP box with an 11/73 CPU, 4 meg of memory, DHV11 for eight
serial lines (probably only use one to talk to a TU58 emulator
but the DHV11 was just sitting there looking lonely) a DEQNA
and a CMD SCSI Controller set for 6 disks and one tape. Only
thing it lacks at this point is software.
The TU58 like a responsive IO a DLV11J
is a better choice for console and DD
and works best if first card after the memory (early in the interrupt
grant chain). The simulators are faster than tu58 so it makes for
fewer retries.
I use DHV11 for terminal and modem lines (slower stuff).
More surprising than most would accept. It's not a PDP-11 but
I have a 6809 that was sold as a toy for running games that I have
had 4 remote login sessions and a web server running on. And
that was with networked disks and all remote access over a 115K
serial line on a bitbanger port!! I would love to see a version
of that OS on the PDP-11.
bill
On to my next project.
Thanks for all the help. I had forgotten just how much fun
real computers were compared to PC's and MAC's.
Yes they are.? Their
performance without all the gui gunk is often a
suprize
to many that have not worked with them.
6:45 p.m.
On 01/12/2019 05:03 PM, Bill Gunshannon via cctalk wrote:
My 11/73 only has a console, thus the need for the DHV11 but really
only one port. (Although I may try putting multiple serial ports in
all the boxes and doing some "networking" over them. :-) Right the 11/23
and later quad 11/73 have console the dual width without
pulling out
the rack to look did not.
On 1/12/19 4:30 PM, allison via cctalk wrote:
DELQA replace the
DEQNA as often they didn't work, high failure rate in
service.
There was also a DAta corruption bug that also turned up so DELQA was the
replacement.
On 01/12/2019 04:14 PM, Bill Gunshannon via
cctalk wrote:
My only problem is I
have 3 DEQNA and 1 DELQA. I thought I read
somewhere recently that the DEQNA was the better of the two. On 1/12/19 2:25 PM, allison via cctalk wrote:
BA11 box
with one of the usual two common backplanes or standard BA23.
Problem with DEQNA is what OS?? RT11 does nothing with it.? RSX-11
I don't have a recent enough version so its often unused/ On 01/12/2019 12:29 PM, Pete Turnbull via cctalk
wrote:
> On 12/01/2019 01:24, Zane Healy via cctalk wrote:
>
>> I?m pretty sure you could get the /23+, /53, /73, /83, and /93 in
>> either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
>> my /23+.
> I'm fairly certain all microPDP-11/23+ systems were only sold in BA23
> boxes, and I think microPDP-11/73 and the later, cheaper, cut-down
> 11/53 were as well.? But almost all the 11/83 systems I've ever seen
> were in BA123 boxes, though they did sell some in BA23 pedestals -
> I've got one.
>
Pete,
Your right the 11/23+ showed up on a lot of boxes but not the BA123
though it would fit.
My 11/23+ is in a box labeled PDP-11/23PLUS on the front
with
three toggle switches. :-) It has a 9276-A backplane labeled
OPTION 11/23B. It is a 9 slot, Q22 A-B-C-D . That's the home
for my next system which will (hopefully) have 2 meg of memory,
a DEQNA and an Andromeda Card for a small hard disk and 8" floppy. As for software, what about the Kent TCPIP package?
Will that
not work with the DEQNA? I thought the two Ethernet controllers
for QBUS were functionally the same.
Roughly as the DEQNA carried a mop boot loader
but it didn't use it for
RT-11.? RT does nto that I know of through 5.4 support the Ni device
for any internal use, an application can but you get to write code and
create a Decnet endpoint.
I know of now IP stacks for PDP11, they may exist but not in my vocabulary.
I can't see why not though but then you likely need UNIX and what version?
I know V6 doesn't and I have that on RL02.
And, while we are at it, if I type BOOT XH does it
look for a
MOP Server?
For RSX it may work as RSX later versions supported networking.
I also plan on another small 11/23 with 128KW of
memory and an
18 bit backplane so I can use the RX02 emulator. And, probably
an Andromeda in there, too
To bring my part of this discussion to an end, I now have a BA23
MicroPDP box with an 11/73 CPU, 4 meg of memory, DHV11 for eight
serial lines (probably only use one to talk to a TU58 emulator
but the DHV11 was just sitting there looking lonely) a DEQNA
and a CMD SCSI Controller set for 6 disks and one tape. Only
thing it lacks at this point is software.
The TU58 like a responsive IO a DLV11J
is a better choice for console and DD
and works best if first card after the memory (early in the interrupt
grant chain). > The simulators are faster than tu58 so it makes
for fewer retries.
> I use DHV11 for terminal and modem lines (slower stuff).
>> On to my next project.
>>
>> Thanks for all the help. I had forgotten just how much fun
>> real computers were compared to PC's and MAC's.
> Yes they are.? Their performance without all the gui gunk is often a
> suprize to many that have not worked with them.
I've had people running stuff on a 486/dx33 with 8mb (win3.11 as DOS 5.22)
and RT11 on PDP11/23 with 512kbyte? and totally blew their minds.? The 11
ran a lot of stuff that the PC could and was faster.? Then they got to
see it as
a multiuser system with RSTS, push them over with a feather.?? The
multitasking and multiuser aspect shows it off.? Side effect of time and
maturity of OS and Instruction set with good hardware.
The Storage systems were better and MMU made swapping and memory
management cleaner so beat the tar off segmentation and early Intel 32bit
(386/486 era) as it didn't do context switching at all well (slow).
Once graphics found home then it had to a VAX/VMS on a 3100/GPX
and a color tube to get the same level wow.
> More surprising than most would accept. It's
not a PDP-11 but
> I have a 6809 that was sold as a toy for running games that I have
> had 4 remote login sessions and a web server running on. And
> that was with networked disks and all remote access over a 115K
> serial line on a bitbanger port!! I would love to see a version
> of that OS on the PDP-11.
>
The 6809 (hitachi 63B09) are about as close to PDP11 in general
structure and
instruction set and could boogy.?? The were a cusp 16 bitter (not really
but close).
The 8088/86 was not wonderful, and what came after had all the side baggage
to not help.?? At that time I was voting for 68000 to win!
Allison
7:34 p.m.
On 1/12/19 6:45 PM, allison via cctalk wrote:
I don't think any common PDP-11 OS could net boot, but that doesn't
mean I can't do it myself. I was wondering how hard it would be to
get Xinu to netboot rather than boot over a serial line. :-)
My 11/73 only has a console, thus the need for the DHV11 but really
only one port. (Although I may try putting multiple serial ports in
all the boxes and doing some "networking" over them. :-) Right the
11/23 and later quad 11/73 have console the dual width without
pulling out
the rack to look did not.
Not my 11/73. The 23's have two ports but the 73 only had one.
We;ll see. I may take a shot at doing a PDP-11 port of NitrOS9. :-)
I would also like to do early MINIX. And, netbooting of almost
anything with some form of disk server for diskless running.
Amazing what fun you can have when your not doing it for money.
On 01/12/2019 05:03 PM, Bill Gunshannon via cctalk
wrote:
And then there was the old how to crash a PDP-11 (and I think early
VAX as well) by flooding a network. Luckily all of mine will be on
switches and accidental flooding won't happen. Of course that doesn't
mean I won;t try it just for fun.
On 1/12/19 4:30 PM, allison via cctalk wrote:
DELQA replace the
DEQNA as often they didn't work, high failure rate in
service.
There was also a DAta corruption bug that also turned up so DELQA was the
replacement. On 01/12/2019 04:14 PM, Bill Gunshannon via
cctalk wrote:
My only problem is I
have 3 DEQNA and 1 DELQA. I thought I read
somewhere recently that the DEQNA was the better of the two. On 1/12/19 2:25 PM, allison via cctalk wrote:
> On 01/12/2019 12:29 PM, Pete Turnbull via cctalk wrote:
>> On 12/01/2019 01:24, Zane Healy via cctalk wrote:
>>
>>> I?m pretty sure you could get the /23+, /53, /73, /83, and /93 in
>>> either a BA23 or a BA123.? I have an actual badged BA23 pedestal for
>>> my /23+.
>> I'm fairly certain all microPDP-11/23+ systems were only sold in BA23
>> boxes, and I think microPDP-11/73 and the later, cheaper, cut-down
>> 11/53 were as well.? But almost all the 11/83 systems I've ever seen
>> were in BA123 boxes, though they did sell some in BA23 pedestals -
>> I've got one.
>>
> Pete,
>
> Your right the 11/23+ showed up on a lot of boxes but not the BA123
> though it would fit.
My 11/23+ is in a box labeled PDP-11/23PLUS on the front with
three toggle switches. :-) It has a 9276-A backplane labeled
OPTION 11/23B. It is a 9 slot, Q22 A-B-C-D . That's the home
for my next system which will (hopefully) have 2 meg of memory,
a DEQNA and an Andromeda Card for a small hard disk and 8" floppy.
BA11 box
with one of the usual two common backplanes or standard BA23.
Problem with DEQNA is what OS?? RT11 does nothing with it.? RSX-11
I don't have a recent enough version so its often unused/ As for software, what about the Kent TCPIP
package? Will that
not work with the DEQNA? I thought the two Ethernet controllers
for QBUS were functionally the same.
Roughly as the DEQNA carried a mop boot
loader but it didn't use it for
RT-11.? RT does nto that I know of through 5.4 support the Ni device
for any internal use, an application can but you get to write code and
create a Decnet endpoint.
I know of now IP stacks for PDP11, they may exist but not in my vocabulary.
I can't see why not though but then you likely need UNIX and what version?
More than one as far as I know. Johnny Billquist did one for RSX.
I thought Process Software had one before they settled on only VMS.
TCPIP for TSX and RT-11 from kent.edu. (I have never used it but I
have been told by people more knowledgeable than myslf that is works
really well. I plan to find out now.)
And, of course, Ultrix-11 and BSD2.11 both have full networking.
I know V6 doesn't and I have that on RL02.
I am not worried about what will be downloaded (yet), just what typing
BOOT XH actually does. I guess I will noe for sure when I try it with
a network monitor running. If it works as I hope, I have a lot of
experience MOP Booting other devices.
And, while we are at it, if I type BOOT XH does
it look for a
MOP Server?
For RSX it may work as RSX later versions supported networking.
I also plan on another small 11/23 with 128KW of
memory and an
18 bit backplane so I can use the RX02 emulator. And, probably
an Andromeda in there, too
To bring my part of this discussion to an end, I now have a BA23
MicroPDP box with an 11/73 CPU, 4 meg of memory, DHV11 for eight
serial lines (probably only use one to talk to a TU58 emulator
but the DHV11 was just sitting there looking lonely) a DEQNA
and a CMD SCSI Controller set for 6 disks and one tape. Only
thing it lacks at this point is software.
The TU58 like a responsive IO a DLV11J
is a better choice for console and DD
and works best if first card after the memory (early in the interrupt
grant chain). > The simulators are faster than tu58 so it
makes for fewer retries.
> I use DHV11 for terminal and modem lines (slower stuff).
>> On to my next project.
>>
>> Thanks for all the help. I had forgotten just how much fun
>> real computers were compared to PC's and MAC's.
> Yes they are.? Their performance without all the gui gunk is often a
> suprize to many that have not worked with them.
I've had people running stuff on a 486/dx33 with 8mb (win3.11 as DOS 5.22)
and RT11 on PDP11/23 with 512kbyte? and totally blew their minds.? The 11
ran a lot of stuff that the PC could and was faster.? Then they got to
see it as
a multiuser system with RSTS, push them over with a feather.?? The
multitasking and multiuser aspect shows it off.? Side effect of time and
maturity of OS and Instruction set with good hardware.
The Storage systems were better and MMU made swapping and memory
management cleaner so beat the tar off segmentation and early Intel 32bit
(386/486 era) as it didn't do context switching at all well (slow).
Once graphics found home then it had to a VAX/VMS on a 3100/GPX
and a color tube to get the same level wow.
> More surprising than most would accept.
It's not a PDP-11 but
> I have a 6809 that was sold as a toy for running games that I have
> had 4 remote login sessions and a web server running on. And
> that was with networked disks and all remote access over a 115K
> serial line on a bitbanger port!! I would love to see a version
> of that OS on the PDP-11.
>
The 6809 (hitachi 63B09) are about as close to PDP11 in general
structure and
instruction set and could boogy.?? The were a cusp 16 bitter (not really
but close).
The 8088/86 was not wonderful, and what came after had all the side baggage
to not help.?? At that time I was voting for 68000 to win!
Too bad Motorola had scruples. We got stuck with Intel.
bill
8:07 p.m.
New subject: PDP-11 BETTER
On 1/12/2019 4:45 PM, allison via cctalk wrote:
The 6809 (hitachi 63B09) are about as close to PDP11
in general
structure and
instruction set and could boogy.?? The were a cusp 16 bitter (not really
but close).
The 8088/86 was not wonderful, and what came after had all the side baggage
to not help.?? At that time I was voting for 68000 to win!
So was I, but all we got was the MAC (128K memory) and game machines.
Allison
I am building a TTL computer from 1973 as I said earlier. This is to
compiete
with the PDP 11 and the PDP 8. Major design features a single memory bus
and character I/O (10 bits) and word/character addressing.
The hardest part is getting a card edge connector for the bus, in .156 inch
pitch. All I can find are 28/56 and 36/72 pin connectors. A possible
design is loosely based of the 6800 cpu but 18 bits. EBAY for the hard
to find parts and the rest off the shelf TTL or LS part depending the
bus clock. Since proms seem to out in 1973 I will be using them.
876 543 210 987 654 321
+-----------------------+
|ooo|baa|xx-|?##|###|###| normal opcode
+-----------------------+
+-----------------------+
|ooo|I00|###|###|###|##0| bcc opcode + 1K words
+-----------------------+
+-----------------------+
|00h|000|00-|000|000|000| hlt opcode
+-----------------------+
+-----------------------+
|000|000|xx.|?##|###|###| lea opcode
+-----------------------+
ooo opcode b byte aa jmp,ac,ix,sp xx #,Z,ix,sp
A simpler 20 bit cpu is possible but might be to
primitive a design with only word addressing
and possible random logic design having NO proms
in the design.
+-----------------------+
|ooobaa|xx####|####|####| normal opcode
+-----------------------+
It is really amazing how fast electronics changed between
1971 and 1976.
Ben.
9:46 p.m.
New subject: PDP-11 BETTER
Ben said
I am building a TTL computer from 1973 as I said
earlier. This is to
compiete
with the PDP 11 and the PDP 8. Major design features a single memory bus
and character I/O (10 bits) and word/character addressing.
It sounds like you are building a machine similar to the EDUC-8, which was a hardwired
machine built from 96 TTL ICs and unashamedly based on the PDP-8. Here's the front
cover of
Electronics Australia magazine, December 1974 showing it in front of a Straight 8 at
Fairfax
publishing, Sydney. The project construction articles started a few months earlier in
August,
pipped by the Mark-8 by just a month. The construction articles are still available as a
small
book.
http://www.surfacezero.com/g503/uploads/612/EA_Dec_1974_cover.jpg
Steve.
11 Jan
11 Jan
6:58 p.m.
On Fri, Jan 11, 2019 at 3:51 PM Bill Gunshannon via cctalk
<cctalk at classiccmp.org> wrote:
Mine are all BA23. Wasn't the BA123 for the
MicroVAX?
As sold, most likely. I don't think DEC ever configured any MicroPDP
systems in a BA123 but no reason it doesn't work.
I got an empty BA123 a while back and when I get a nice KDJ11 board,
I'll load it up. I already have a KA610 and KA630 in BA23 boxes.
-ethan
12 Jan
12 Jan
12:24 p.m.
On 11/01/2019 23:58, Ethan Dicks via cctalk wrote:
On Fri, Jan 11, 2019 at 3:51 PM Bill Gunshannon via
cctalk
<cctalk at classiccmp.org> wrote:
Absolutely not so - there were very many microPDP-11/83 systems sold in
BA123 cabinets, in fact probably more in BA123 than in BA23. The
MicroPDP-11 System Maintenance Manual features the BA123 heavily
throughout, as do other microPDP-11 manuals.
--
Pete
Pete Turnbull
Mine are all BA23. Wasn't the BA123 for the
MicroVAX?
As sold, most likely. I don't think DEC ever configured any MicroPDP
systems in a BA123 but no reason it doesn't work.
12:36 p.m.
On 1/12/19 12:24 PM, Pete Turnbull via cctalk wrote:
On 11/01/2019 23:58, Ethan Dicks via cctalk wrote:
None of my MicroPDP-11 manuals show anything but the BA23. Most
show the install as being in a deskside pedestal. But even the
one that shows rack mount installation is only BA23.
bill
On Fri, Jan 11, 2019 at 3:51 PM Bill Gunshannon
via cctalk
<cctalk at classiccmp.org> wrote:
Absolutely not so - there were very many microPDP-11/83 systems sold in
BA123 cabinets, in fact probably more in BA123 than in BA23.? The
MicroPDP-11 System Maintenance Manual features the BA123 heavily
throughout, as do other microPDP-11 manuals.
Mine are all BA23.? Wasn't the BA123 for the
MicroVAX?
As sold, most likely.? I don't think DEC ever configured any MicroPDP
systems in a BA123 but no reason it doesn't work.
2 p.m.
On 01/12/2019 12:36 PM, Bill Gunshannon via cctalk wrote:
On 1/12/19 12:24 PM, Pete Turnbull via cctalk wrote:
And my older manuals don't show anything other than BA11, later manuals
are useful for that reason.
Allison
On 11/01/2019 23:58, Ethan Dicks via cctalk
wrote:
None of my MicroPDP-11 manuals show anything but the BA23. Most
show the install as being in a deskside pedestal. But even the
one that shows rack mount installation is only BA23.
bill On Fri, Jan 11, 2019 at 3:51 PM Bill Gunshannon
via cctalk
<cctalk at classiccmp.org> wrote:
Absolutely not so - there
were very many microPDP-11/83 systems sold in
BA123 cabinets, in fact probably more in BA123 than in BA23.? The
MicroPDP-11 System Maintenance Manual features the BA123 heavily
throughout, as do other microPDP-11 manuals.
Mine are all BA23.? Wasn't the BA123 for the
MicroVAX?
As sold, most likely.? I don't think DEC ever configured any
MicroPDP
systems in a BA123 but no reason it doesn't work.
11 Jan
11 Jan
3:24 p.m.
On 01/11/2019 02:32 PM, Noel Chiappa via cctalk wrote:
I'm far from
a newby to Qbus 11s as I stated with LSI-11 nearly 4
decades ago
and I ahve all Qbus models of note from LSI-11(quad), 11/2 (dual) ,
11/23(dual)
11/23(quad), 11/23B(quad), 11/73(dual) in various BA11VA,? BA-11s, BA11N,
BA23, BA123, and also microVAXII in BA23 and BA123.? Which covers about
eight different Qbus backplane variations not including the Heath H11 and a
engineering one off (8 slot dual width with bigger supply sorta like
taller a
BA11VA 4 slot.? Small advantage to being a Millrat.?? I forgo most
non-Qbus 11s
to specialize.
All of my 11s are Qbus and yes they complain if the interrupt grant
chain is broken.
Missing CSR is the usual complaint.
Typical micorpdp-11 Qbus is:
First three slots after CPU the CD slots are open use, or be used or
memory private bus.
ABCD CPU
ABCD? where CD is memory wired not bus
ABCD
ABCD? up to this slot memory does not have to grant interrupts on the
right (CD)side of quad cards
ABAB? All cards dual or quad must have int grant jumper of the board or
grant card.
ABAB
ABAB
ABAB
From: Allison
Parent
Most Probable cause is interrupt grant is broken.
The only -11 that complains if the grant chain is broken that I know of is
the /34 (maybe the /04 too). I certainly have a QBUS chassis right next to my
workstation here that i) has a bunch of empty slots, and ii) works fine, as
long as there are no empty slots between the CPU and the devices. Also, IIRC he said it works with 3 cards plugged in,
but not 4; how can
plugging a card _in_ cause grant problems?
See the above...? Qbus is can or cannot
be uniform for quad or dual
width cards.
For most only bus slots that are AB bussed are data/address.? But they
can be
serpentine for quad wide systems and most quad wide board have interrupt
grant jumpers on the board or are just hardwired that way.
Qbus is not Unibus.? You can build a Qbus system of all dual width
cards, some
Qbus system memory uses PMI.?
For example I have an 11/23b+ in a quad width BA11-N but the backplane is
nonstandard ,18 slots of Q22 ABAB (serpentine wired).? It has? a quad
width 11/23B
and 8 MSV11 256KB dual width Q22 memory. RQDX3 dual width, RXV21 RX02,
DRV11J and a M7555 (also found in MicroVAXII in BA123 boxes, takes the
50pin
wide RQDX breaks it out for multiple RX33 floppy and RD32 drives).
There are many Qbus? backplanes? and several different configurations for
DUAL/QUAD mixes of cards.? The Microvax Qbus backplanes also fit in that
realm such as BA123 with J11 cpus installed and PMI ram.? Also many of the
Qbus can be Q16(not many), Q18(fairly common) and Q22(only late and
MicroVax) address bus width.
The microcomputers handbook is a start and the modules manuals.
Typically you need a 1980 version and a later 80s versions.? Also the
LSI-11 Systems Service Manual Volumes 1 and 2.? Generally the more
docs you have for Qbus 11 systems and the MicroVAX kin the less pain
you will have configuring them especially for non standard configurations
or systems with mix and match boards.
Allison
3:44 p.m.
On 1/11/19 3:24 PM, allison via cctalk wrote:
On 01/11/2019 02:32 PM, Noel Chiappa via cctalk
wrote:
I'm far from
a newby to Qbus 11s as I stated with LSI-11 nearly 4
decades ago
Me too. :-) I have had them in my house for more than two decades.
No more UNIBUS (but I really miss my 11/24 which was my first personal
PDP-11).
From:
Allison Parent
Most Probable cause is interrupt grant is broken.
The only -11 that complains if the grant chain is broken that I know of is
the /34 (maybe the /04 too). I certainly have a QBUS chassis right next to my
workstation here that i) has a bunch of empty slots, and ii) works fine, as
long as there are no empty slots between the CPU and the devices. and I ahve all Qbus models of note from LSI-11(quad),
11/2 (dual) ,
11/23(dual)
11/23(quad), 11/23B(quad), 11/73(dual) in various BA11VA,? BA-11s, BA11N,
BA23, BA123, and also microVAXII in BA23 and BA123.? Which covers about
eight different Qbus backplane variations not including the Heath H11 and a
engineering one off (8 slot dual width with bigger supply sorta like
taller a
BA11VA 4 slot.? Small advantage to being a Millrat.?? I forgo most
non-Qbus 11s
to specialize.
I have so many different backplanes I have to look them up every time
I pull a different system out. But I have been playing with the
hardware for a while so none of them were "official" configurations.
Or stable configurations as I kept changing them.
But, now I need to build a few stable, supported systems so I can
play with some software.
All of my 11s are Qbus and yes they complain if the interrupt grant
chain is broken.
Missing CSR is the usual complaint.
That's interesting. All I ever saw from a missing bus grant was
a dead machine where the CPU wouldn't even run. Going to have to
review it, but as I said earlier a quick glance at the memory cards
shows bus grant pins connected with a trace.
Typical micorpdp-11 Qbus is:
First three slots after CPU the CD slots are open use, or be used or
memory private bus.
Are you sure? My Pocket Service Guide confirms what I said.
First three slots A-B-C-D all the rest serpentine A-B.
ABCD CPU
ABCD? where CD is memory wired not bus
ABCD
ABCD? up to this slot memory does not have to grant interrupts on the
right (CD)side of quad cards
ABAB? All cards dual or quad must have int grant jumper of the board or
grant card.
ABAB
ABAB
ABAB
> Also, IIRC he said it works with 3 cards plugged in, but not 4; how can
> plugging a card _in_ cause grant problems?
He is right here. The third memory card in in a pair of A-B slots.
The first serpentine. The fourth memory card would be in the next
A-B pair but o n the revers of the serpentine. S, actually there
are two A-B slots between them that need bus grant. Now I need
to figure out why the bus grand is not going thru.
See the above...? Qbus is can or cannot be uniform for
quad or dual
width cards.
For most only bus slots that are AB bussed are data/address.? But they
can be
serpentine for quad wide systems and most quad wide board have interrupt
grant jumpers on the board or are just hardwired that way.
Qbus is not Unibus.? You can build a Qbus system of all dual width
cards, some
Qbus system memory uses PMI.
For example I have an 11/23b+ in a quad width BA11-N but the backplane is
nonstandard ,18 slots of Q22 ABAB (serpentine wired).? It has? a quad
width 11/23B
and 8 MSV11 256KB dual width Q22 memory. RQDX3 dual width, RXV21 RX02,
DRV11J and a M7555 (also found in MicroVAXII in BA123 boxes, takes the
50pin
wide RQDX breaks it out for multiple RX33 floppy and RD32 drives).
There are many Qbus? backplanes? and several different configurations for
DUAL/QUAD mixes of cards.? The Microvax Qbus backplanes also fit in that
realm such as BA123 with J11 cpus installed and PMI ram.? Also many of the
Qbus can be Q16(not many), Q18(fairly common) and Q22(only late and
MicroVax) address bus width.
The microcomputers handbook is a start and the modules manuals.
Typically you need a 1980 version and a later 80s versions.? Also the
LSI-11 Systems Service Manual Volumes 1 and 2.? Generally the more
docs you have for Qbus 11 systems and the MicroVAX kin the less pain
you will have configuring them especially for non standard configurations
or systems with mix and match boards.
My documentation is very limited and my memory isn't what it used
to be. But this seems like a problem that should not be there.
At least it gives me something to do now that it is too cold to
go outside.
Nothing worse than being this cold and the slopes have no snow
on them. :-)
bill
2022
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2024
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31 comments
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allisonportable＠gmail.com -
bfranchuk＠jetnet.ab.ca -
bill.gunshannon＠hotmail.com -
binarydinosaurs＠gmail.com -
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healyzh＠avanthar.com -
imp＠bsdimp.com -
jnc＠mercury.lcs.mit.edu -
jsw＠ieee.org -
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steven＠malikoff.com