RE: DEC top-mount corporate cabinet
Chris:
The traditional DEC racks/cabinets are either full-height ("standard" =
H960) and part-height ("short" = H967) 19" racks. These are welded steel
frames built for computer-room type environments. When DEC started selling
into office environments (think data processing / business operations) they
designed a new line of cabinetry that was intended to fit into an office
where sight-lines are important and the desire was to look/work more like
other types of office equipment. The PDP-11/60 was I think an early example
of the redesigned cabinets -- really a double-wide plus a bit, but of more
modest height (roughly that of the H967). After that you see single-width
cabinets holding just 18U like the one that you have -- capable of holding a
complete, but modest, system. These newer-style cabinets/racks are riveted,
rather than welded. Emphasis was on style, cost-effectiveness, and RF
shielding given the need to operate near other types of office equipment.
Here's a good overview:
http://vtda.org/docs/computing/DEC/Catalogs/EA21388-75_CabinetAccessoriesSup
pliesCatalog1981.pdf
On the left side of page 8-of-16 you'll see a description of the 40" Medium
Systems Series, including diagrams and pictures of the "top-loader"
(H9642-AD) and "front-loader" (H9642-CA) designs. There isn't any "mod-kit"
to go from one to the other. It would be possible to get a functional
top-loader out of a front-loader with some metal reworking. Basically,
remove the lid and then (in effect) move the cross-pieces down 6U and add
what amount to four gusset plates for lateral bracing. In the H9642-AD
photo you can see the plates on the rear cross-piece. The front is similar,
but sensitive to ensuring that the center 6U isn't significantly occluded;
the front cross-piece may require some modification. There are a few other
changes but moving the cross-pieces down are the key. Notice the H9544 CA
Trim Kit, RL01/RL02 -- these are plastic pieces that bridge the gap between
the HDD cover and the cabinet side-panels; nice to have but they're mostly
there for style.
If you decide to attempt (or simply want to gauge the complexity of) a
conversion I can see about getting some close-up photos of the various
components and connections. A conversion would not be a simple task.
While the brochure speaks of "purchase as component kits" and the table
simply states "Basic Frame Kit", it's not the *same* frame kit for -AD and
-CA, and I suspect that "kit" in this case was not an IKEA flat-box of parts
but rather a factory-assembled frame to which one added other components as
appropriate for the intended use. These frames are _seriously_ riveted.
Notice that H9542-AD is distinct from the H9542-CA "component kit".
(Note that the TU80 -- http://gunkies.org/w/images/5/52/Tu80.jpg -- is
basically a H9642-AD "top-loader" with a hinged lid and special-purpose 13U
front.)
-Original Message-
From: Chris Elmquist
Sent: Monday, February 28, 2022 2:08 PM
To: pbir...@gmail.com; General Discussion: On-Topic and Off-Topic Posts
Subject: DEC top-mount corporate cabinet
On Saturday (02/26/2022 at 03:21PM -0500), pbirkel--- via cctalk wrote:
> A top-mount corporate cabinet looks like this:
> http://www.cosam.org/images/pdp11-23/front2.jpg The "DECDatasystem"
> front-bar in the photo is over the 1U strengthener that braces the
> upper portion of the rack ... since there is no brace at the top (as yours
has).
> Your cabinet will work fine; in my experience RL02's are always tight
> and fiddly any place but the top-spot.
Is there a (hand-)book that describes the DEC cabinets and in particular
this "top-mount corporate cabinet"? Is there a BA # for this cabinet?
I have an 11/34 in said cabinet but it is missing this 1U strengthener
although I do have the 1U front-bar. I had to jigger a means to hold the
front-bar in place and have been unable to understand how it would correctly
attach to the rack and the strengthener, probably because I don't have the
strengthener!
Any part numbers or drawings that show this arrangement would be quite
helpful.
Thanks!
Chris
--
Chris Elmquist
RE: Tandon TM 848-02
Page #14 of: http://www.bitsavers.org/pdf/tandon/TM848-1_TM-848-2_Product_Specification_Mar81.pdf Unless "-02" is different than "-2" ... -Original Message- From: cctalk On Behalf Of Bill Gunshannon via cctalk Sent: Wednesday, February 23, 2022 6:13 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Tandon TM 848-02 Does anyone have anything on the jumper settings for this drive? I would like to jumper it so it can read DEC RX01/RX02 floppies. I am looking at being able to read disks on a non-DEC systems but I would also like to be able to use it on my Andromeda card in a real PDP-11. bill
Re: DEC top-mount corporate cabinet
Thanks very much Paul and others. The overview you linked is very
helpful as I now have the actual model number for the rack that I have.
It is indeed the H9642-AD 40" "Top Loader" but it is missing whatever
cross piece goes behind the H9544 DA Bezel (#4) shown in the component
parts diagram.
My mystery is what that cross piece behind the bezel looks like, how
it attaches to the vertical rails of the rack on each side and then how
the bezel attaches to the cross piece.
The back of the bezel has a ribbed channel that looks like some kind of
bolts or other threaded or inserted fasteners were screwed or snapped
into this channel and those were attached to the cross piece somehow.
That's my missing link ...
I fabricated an aluminum bar cross piece and then used heavy duty
hook and loop-like fasteners to attach the bezel to this aluminum bar
but it's cheesy and loose. I'd like to someday find the proper solution.
Chris
On Tuesday (03/01/2022 at 03:23AM -0500), pbir...@gmail.com wrote:
> Chris:
>
> The traditional DEC racks/cabinets are either full-height ("standard" =
> H960) and part-height ("short" = H967) 19" racks. These are welded steel
> frames built for computer-room type environments. When DEC started selling
> into office environments (think data processing / business operations) they
> designed a new line of cabinetry that was intended to fit into an office
> where sight-lines are important and the desire was to look/work more like
> other types of office equipment. The PDP-11/60 was I think an early example
> of the redesigned cabinets -- really a double-wide plus a bit, but of more
> modest height (roughly that of the H967). After that you see single-width
> cabinets holding just 18U like the one that you have -- capable of holding a
> complete, but modest, system. These newer-style cabinets/racks are riveted,
> rather than welded. Emphasis was on style, cost-effectiveness, and RF
> shielding given the need to operate near other types of office equipment.
>
> Here's a good overview:
> http://vtda.org/docs/computing/DEC/Catalogs/EA21388-75_CabinetAccessoriesSup
> pliesCatalog1981.pdf
>
> On the left side of page 8-of-16 you'll see a description of the 40" Medium
> Systems Series, including diagrams and pictures of the "top-loader"
> (H9642-AD) and "front-loader" (H9642-CA) designs. There isn't any "mod-kit"
> to go from one to the other. It would be possible to get a functional
> top-loader out of a front-loader with some metal reworking. Basically,
> remove the lid and then (in effect) move the cross-pieces down 6U and add
> what amount to four gusset plates for lateral bracing. In the H9642-AD
> photo you can see the plates on the rear cross-piece. The front is similar,
> but sensitive to ensuring that the center 6U isn't significantly occluded;
> the front cross-piece may require some modification. There are a few other
> changes but moving the cross-pieces down are the key. Notice the H9544 CA
> Trim Kit, RL01/RL02 -- these are plastic pieces that bridge the gap between
> the HDD cover and the cabinet side-panels; nice to have but they're mostly
> there for style.
>
> If you decide to attempt (or simply want to gauge the complexity of) a
> conversion I can see about getting some close-up photos of the various
> components and connections. A conversion would not be a simple task.
>
> While the brochure speaks of "purchase as component kits" and the table
> simply states "Basic Frame Kit", it's not the *same* frame kit for -AD and
> -CA, and I suspect that "kit" in this case was not an IKEA flat-box of parts
> but rather a factory-assembled frame to which one added other components as
> appropriate for the intended use. These frames are _seriously_ riveted.
> Notice that H9542-AD is distinct from the H9542-CA "component kit".
>
> (Note that the TU80 -- http://gunkies.org/w/images/5/52/Tu80.jpg -- is
> basically a H9642-AD "top-loader" with a hinged lid and special-purpose 13U
> front.)
--
Chris Elmquist
PDT-11 Virtual Terminal Monitor v1.07
Hi! Anyone remember how to use this program that announces itself as "PDT-11 Virtual Terminal Monitor v1.07" ? I found it on a floppy of RT-11 v4.0 with my pile of PDT-11 treasures (which amazingly still seem to read fine and work wonderfully; disk file timestamps around 1979 - 1982). I thought maybe it was a term program, since these PDTs were kind of famous for that sort of deployment, and tried looping back pin 2 to pin 3 on each serial + modem port and typing some characters, but nothing shows up in vterm. It does come out of some mode into a command mode, I think, when I send a break to the console. ^C kills it from there and I can get back to RT. I found online a DECUS program of the same name (vterm), submitted by DEC circa 1979, and am wondering if this is the same beastie I've discovered on my 8" floppy: https://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/decus/110417.html ; however, when I try to click through that decus website, the actual packages themselves seem to have been lost! Does anyone know where to obtain the actual files that came with this 110417 from DECUS? And if I'm on the right track, here? It would be cool to have this PDT-11 functioning as God intended if this vterm is actually a terminal emulator type of thing... thx jake
