Thank you for the reply. 'General at a 1U replaces the I saw something somewhere that suggested the RL02 should be at the top with the disk accessible without pulling out the drive. I don't think the cabinet I have was intended to do that, but I will have a closer look. that raising I did try raising the CPU as high as possible. Will have another look to see if the RL02s can be dropped a bit lower, but I don't think they can go lower in terms of using lower slots, not unless I want to leave a gap and possible interfere with the space at the bottom where there will be some cables I think. I would like to avoid filing though! repeat the to flanges on have (no There *is* a bit of play in the big black sheet that is screwed onto CPU enclosure. *really* move the the enough

extended) don't Ah! Thanks for that advice. cabinet see lower possible

On 2/28/22 14:07, Chris Elmquist via cctalk wrote: There's a picture of one with the 11/24 in the small box in it on the cover of the 1981 PDP11 Processor Handbook. You can see from the spacer between the 11/24 and the bottom RL02 that it could also accommodate the larger box version of the 11/24. bill

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 <chrise at pobox.com> Sent: Monday, February 28, 2022 2:08 PM To: pbirkel at gmail.com; General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: DEC top-mount corporate cabinet On Saturday (02/26/2022 at 03:21PM -0500), pbirkel--- via cctalk wrote: has). 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

Your description sounds like the cabinet has already been hacked by a prior owner to remove a key component. And you're saying that the rear cross-piece is present but both of the top cross-pieces are absent? Completely weird. I'll contact you off-list and we can exchange photos to determine what's-what. -----Original Message----- From: Chris Elmquist <chrise at pobox.com> Sent: Tuesday, March 1, 2022 5:21 PM To: pbirkel at gmail.com Cc: 'General Discussion: On-Topic and Off-Topic Posts' <cctalk at classiccmp.org> Subject: 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), pbirkel at gmail.com wrote: shielding given the need to operate near other types of office equipment. "mod-kit" there for style. are _seriously_ riveted. -- Chris Elmquist

<cctalk at classiccmp.org> cabinet, above I am not in the USA, but I am should be able to look for other screwdrivers here in the UK. I already have one quite big one, but I think it is still way too small for this purpose. attach

How big is it? For ridiculously large flat-blade screws, look at "drag link socket"s. For just getting extreme amounts of torque, use a bit on a ratchet, rather than on a screwdriver handle.

situation It seems Brownells exists here too, although it seems to be like Mouser where items actually ship from the USA. I had not heard the term hollow ground before, although I think I know what they are. serve...