pontus> What does the rails for a TU56 look like? I could not find pontus> any holes on the sides, are they simply screwed in place with pontus> the holes behind the flip-front? My TU56: pontus> http://www.update.uu.se/~pontus/slask/pdp8/tu56.jpg That's how I remember it (on the PDP11 -- but same rack and the tape drive chassis is the same). One drive TU56... interesting, didn't know those existed. I've only seen pictures of one drive TU55s, but clearly that's not what you have (the unit selector switch gives it away). paul

On Mon, Jan 5, 2009 at 4:27 PM, Pontus <pontus at update.uu.se> wrote: Nice. My recollection is that you do just bolt the drive to the rack, no rails. My PC04 has a set of rails that are half as deep as the rack, with a connecting bar for stiffness, and looks exactly like the one in the picture... the left and right rails are the grey parts with the large triangle, and the connecting bar is cadmium-plated steel, part of which you can barely see in the picture. The device rails are the same as other devices of the era (grey steel with sort of a _+-----+_ cross-section, but only as deep as the PC04 itself - i.e., they are *not* 3' long and do not hang out from the back. Probably the most common device of the era with that style of slide is the RX01/RX02 disk drive, but the RX rails _are_ as deep as the rack (same cross-section and color scheme, etc). I even have a few devices with 3rd party chrome-finish rails, but they rarely fit the factory holes in the CPU and device chassis, so are typically re-drilled. I even have one of those (full of PDP-11 gear), but I don't know the DEC model number. Sorry. I, too, have more devices than rails. For light-weight devices (PC04, not RK05), you might consider modern slide-out shelves. For heavier devices, you might consider fixed shelves. They will be easier to find than real DEC rails. Many modern rails are snap-on, and will be "interesting" to retrofit to 30-year-old devices, but not impossible, if all you really need is something that slides in and out. -ethan

I thinkl that makes it a PR04. [..] I think so (although it wouldn't be a bad idea to put a coule of bits of aluminium angle from front to back under the TU56 to support the chassis). There's no need to have the TU56 pull out, you see. You can get to the flip-chip boards from the back and the front panel/transport hinges down for access. Now those are a little strage. They're quite short, not much deeper than the PC04 chassis. The rails are in 3 secions (as normal), one screws to the side of the PC04 chassis,. then the normal 'middle section' that slides over the rail o nthe PC04 and into the rail on the cabinet, and finally the cabinet-mounted part. That one has a large plate and the front end with a flange to fix to the front rail of the rack (screws in rear flange of said front rail in a real DEC rack. Finally there's a tie bar that's crewed between the rear ends of the cabinet-mounted secions, just behind the PC04 chassis. The thing is theese rails mount only tor the front upreights, nothing goes the full depth of the rack. -tony