28 Nov
2016
28 Nov
'16
6:20 a.m.
From: Pontus Pihlgren
The machine also has a qbus which is somewhat peculiar
to find in a
desktop VAX.
I don't know much about Vaxen, but I think the early desktop ones all had a
QBUS. I'm not sure if it was ever used for memory access; I know some used it
as an I/O bus (to take advantage of all the existing QBUS I/O devices), and
used an 'over-the-back' cable system for the memory bus.
However, I don't have the cables necessary to
attach a QBUS expansion.
Does anyone have a set? What do they even look like?
They are a pair of boards connected with a pair of 50-pin cables. The boards
are different on each end, because the QBUS does not have in/out connectors
which separate from device slots, like the UNIBUS; it only has regular QBUS
slots, and those have grant in on different pin from grant out. So on the card
at the end of one backplane, the grant line is connected to the 'grant in'
pin, and on the other card, to the 'grant out' pin.
There are a whole bunch of different card and variants thereof for this, with
and without termination resistors, etc; the M9400/M9401 pair are for Q18
(which you won't want, I'd be pretty sure), and the M9405/M9405 for Q22. One
set I know of is an M9404/M9405-YB.
There's a fair amount of discussion of multi-segment QBUS systems in the QBUS
PDP-11 processor/etc manuals, as far as the termination, etc goes.
As to finding a set, there are some available on eBait at the moment for a
not wholly unreasonable amount of money.
Noel
28 Nov
28 Nov
7:12 a.m.
On 11/28/16 9:20 AM, Noel Chiappa wrote:
Qbus VAXen were all PMI(private memory interface, aka over the top
cable). That means all memory
was always adjacent to the cpu and the CD slots used were unique without
full Qbus signals.
The bus was for IO and allowed devices like RLV11, RQDX2/3, DLV11,
DEQNA/DELQA, DHV11
and many others.
While multibox Qbus VAXen were done it was not a preferred condition and
the suggested
larger BA123 was preferred to the BA23. The required cables mentioned
are needed and
all good care in configuration. Note both (all) chassis should be int
he same rack and have
good common grounding to each other for best system stability along with
a common power
controller (single point power control).
I have two VAXen using a BA23 and a BA123 (both uVAX-II). The latter
BA123 is preferred as
there is far more power and space for cards and media drives as well as
room for cables.
Allison
From: Pontus
Pihlgren
The machine also has a qbus which is somewhat
peculiar to find in a
desktop VAX.
I don't know much about Vaxen, but I think the early desktop ones all had a
QBUS. I'm not sure if it was ever used for memory access; I know some used it
as an I/O bus (to take advantage of all the existing QBUS I/O devices), and
used an 'over-the-back' cable system for the memory bus.
However, I don't have the cables necessary to
attach a QBUS expansion.
Does anyone have a set? What do they even look like?
They are a pair of boards connected with a pair of 50-pin cables. The boards
are different on each end, because the QBUS does not have in/out connectors
which separate from device slots, like the UNIBUS; it only has regular QBUS
slots, and those have grant in on different pin from grant out. So on the card
at the end of one backplane, the grant line is connected to the 'grant in'
pin, and on the other card, to the 'grant out' pin.
There are a whole bunch of different card and variants thereof for this, with
and without termination resistors, etc; the M9400/M9401 pair are for Q18
(which you won't want, I'd be pretty sure), and the M9405/M9405 for Q22. One
set I know of is an M9404/M9405-YB.
There's a fair amount of discussion of multi-segment QBUS systems in the QBUS
PDP-11 processor/etc manuals, as far as the termination, etc goes.
As to finding a set, there are some available on eBait at the moment for a
not wholly unreasonable amount of money.
Noel
7:14 a.m.
On Mon, 28 Nov 2016, Noel Chiappa wrote:
FYI, the VAX 4000-100/105/106 (KA52/KA54/KA54) systems have no backplane
of any kind and do not use Q-bus internally, except for the CQBIC (CVAX to
Q22-Bus Interface Chip) ASIC directly bridging one of the NCA (NDAL to
CDAL Adapter, or the north bridge in modern speak) ASIC's CP peripheral
buses to a mainboard Q-bus connector further wired with an internal cable
assembly to the pair of external connectors mounted on the backside of the
enclosure.
However, I
don't have the cables necessary to attach a QBUS expansion.
Does anyone have a set? What do they even look like?
They are a pair of boards connected with a pair of 50-pin cables. The boards
are different on each end, because the QBUS does not have in/out connectors
which separate from device slots, like the UNIBUS; it only has regular QBUS
slots, and those have grant in on different pin from grant out. So on the card
at the end of one backplane, the grant line is connected to the 'grant in'
pin, and on the other card, to the 'grant out' pin. As to finding a set, there are some available on eBait
at the moment for a
not wholly unreasonable amount of money.
For the record they are DEC P/N BC04V-09 (17-02048-01), though the photos
with the only listing I could find indicate quite a sorry state of the
cables offered I'm afraid.
Maciej
7:31 a.m.
On Mon, Nov 28, 2016 at 03:14:57PM +0000, Maciej W. Rozycki wrote:
FYI, the VAX 4000-100/105/106 (KA52/KA54/KA54) systems have no backplane
of any kind and do not use Q-bus internally, except for the CQBIC (CVAX to
Q22-Bus Interface Chip) ASIC directly bridging one of the NCA (NDAL to
CDAL Adapter, or the north bridge in modern speak) ASIC's CP peripheral
buses to a mainboard Q-bus connector further wired with an internal cable
assembly to the pair of external connectors mounted on the backside of the
enclosure.
Thanks for clearing it up. Uhm, stupid question perhaps. But what is the
CDAL, and what is it's role?
For the record they are DEC P/N BC04V-09 (17-02048-01), though the photos
with the only listing I could find indicate quite a sorry state of the
cables offered I'm afraid.
That looks very familiar... I need to go look in the box with assorted
DEC cables.
/P
9:29 a.m.
On Mon, 28 Nov 2016, Pontus Pihlgren wrote:
CDAL aka CVAX Data and Address Line bus is the original CVAX processor
host bus.
In the NVAX chipset used with the 4000-100/105/106 systems apart from the
CPU(s) the NDAL host bus has two other devices only: the NMC ASIC (NVAX
Memory Controller) and the NCA ASIC (as above; also termed NVAX I/O
Adapter sometimes). The NMC bridges two separate CDAL buses, called CP1
and CP2, which let connect original CVAX peripherals unmodified (so e.g.
the 4000-60's TURBOchannel adapter which interfaces to CDAL can be used
unmodified in the 4000-90/90A/96 systems, which use the same NVAX
chipset). There's a further bridge downstream on one of the CDAL buses,
CEAC (CDAL to EDAL Adapter Chip), which interfaces 16-bit peripherals.
Have a look at VAX 4000-100/105/106 documentation for a block diagram,
which will serve you better than this textual description.
Maciej
FYI, the VAX
4000-100/105/106 (KA52/KA54/KA54) systems have no backplane
of any kind and do not use Q-bus internally, except for the CQBIC (CVAX to
Q22-Bus Interface Chip) ASIC directly bridging one of the NCA (NDAL to
CDAL Adapter, or the north bridge in modern speak) ASIC's CP peripheral
buses to a mainboard Q-bus connector further wired with an internal cable
assembly to the pair of external connectors mounted on the backside of the
enclosure.
Thanks for clearing it up. Uhm, stupid question perhaps. But what is the
CDAL, and what is it's role?
7:34 a.m.
On Mon, Nov 28, 2016 at 03:14:57PM +0000, Maciej W. Rozycki wrote:
For the record they are DEC P/N BC04V-09 (17-02048-01), though the photos
with the only listing I could find indicate quite a sorry state of the
cables offered I'm afraid.
And I forgot, that is just the cable. I suppose you need a matching
board in the QBUS box. Any idea what part number that might be?
/P
8:39 a.m.
On Mon, Nov 28, 2016 at 7:34 AM, Pontus Pihlgren <pontus at update.uu.se> wrote:
And I forgot, that is just the cable. I suppose you need a matching
board in the QBUS box. Any idea what part number that might be?
I have an M9405-PA. It has one male and one female 3-row 50-pin
D-shell connector. I believe that is the board in the expansion
chassis you would cable up to the VAX 4000. It is an s-box handle
board.
Looks like this one:
http://www.ebay.com/itm/151723475931
10:53 a.m.
On Mon, Nov 28, 2016 at 08:39:03AM -0800, Glen Slick wrote:
On Mon, Nov 28, 2016 at 7:34 AM, Pontus Pihlgren
<pontus at update.uu.se> wrote:
Ah, according to my inventory I should have one :D Now I must go look for
the cable.
Thanks everybody!
Pontus
And I forgot, that is just the cable. I suppose you need a matching
board in the QBUS box. Any idea what part number that might be?
I have an M9405-PA. It has one male and one female 3-row 50-pin
D-shell connector. I believe that is the board in the expansion
chassis you would cable up to the VAX 4000. It is an s-box handle
board.
Looks like this one:
http://www.ebay.com/itm/151723475931 
2:34 p.m.
On Mon, Nov 28, 2016 at 19:53 +01:00, Pontus Pihlgren <pontus at update.uu.se>
wrote:
On Mon, Nov 28, 2016 at 08:39:03AM -0800, Glen Slick wrote:
If I may jump in at the end of this thread, I am also interested in playing
with the QBUS capability of my VAX 4000-100A which has the two 50-pin D
connectors as discussed.
I don't want to be able to use regular QBUS cards so I don't envisage the
need for an expansion chassis. What I would like to do is to construct a
simple experimental QBUS device which could enable the VAX to talk to the
outside world in the way of a few output lines that could drive relays or
something similar.
Not having an expansion chassis means that I would not need to get the
cables designed to connect to it and if I had the pinout of the D connectors,
assuming it is not too hard to track down suitable connectirs, I could
hopefully make up cables to connect directly to the experimental device.
Can anyone suggest an existing, simple QBUS device that I could study the
documentation of to figure out what a basic QBUS device needs to have and
to give me some ideas on how to implement one?
I appreciate that if I end up with a device which does not look the same
as some existing QBUS device from a programming point of view, I will
need to come up with suitable device drivers for it too.
Please, no suggestions about drivers and receivers for the QBUS signals,
I will review the many postings on this topic in the list archives.
Regards,
Peter Coghlan.
On Mon, Nov 28, 2016 at 7:34 AM, Pontus Pihlgren
<pontus at update.uu.se> wrote:
Ah, according to my inventory I should have one :D Now I must go look for
the cable.
Thanks everybody!
Pontus
And I forgot, that is just the cable. I suppose you need a matching
board in the QBUS box. Any idea what part number that might be?
I have an M9405-PA. It has one male and one female 3-row 50-pin
D-shell connector. I believe that is the board in the expansion
chassis you would cable up to the VAX 4000. It is an s-box handle
board.
Looks like this one:
http://www.ebay.com/itm/151723475931
2947
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