Supposing you're one of those people that have always wanted a PDP-11/74, but know next to nothing about them. Is there a good guide anywhere for "here's the cards, here's the combinations they'll work in, and here's why mixing this card with that card will work, but isn't a good idea." I'd like to wind up with an 11/74, but I'm willing to work my way there, like say, if I could boot the thing sans front panel, and then find one later. I certainly happy to troll eBay and whatever else picking up what I can, but I have no idea what I should *want*. --jc

On Sunday 14 December 2003 10:36 am, emanuel stiebler wrote: Over the years, the PDP-11 family has come to represent something I've missed in computing history. It's almost reached the point where "well, I'm a programmer, but not a *real* programmer, because I've never driven a PDP-11". Below is a little tale, that will bore most people to death, I'm sure. It is for the same reason that I WILL own a Ferrari 308, at some point. While it's not an F-40, and not a particularly fast car, it represents a design pinnacle of sorts. Yea, they're a little uncomfortable to get in and out of, and maintainence ain't always cheap, but the lines, the history... No where is there a more beautiful car. The PDP-11 has become the 308 of computing for me. I still don't know exactly which 308 I want. Carbs are a nuisance on those things, but they make a little more power, and sound a little more like a Ferrari should. FI is more reliable, but Ferrari FI has this weird idea that when you cold start them, they should immediately jump to a 2K fast idle. Hard top or soft top? Advantages, disadvantages. When I actually have cash in hand, I'll decide. Except for the color. It WILL be red. When I got into computing, the exact year of which I cannot remember (and probably don't want to), the Sol-20 was fairly recently available, and Apples ]['s hadn't come out yet. I had a little minor experience on an IBM mainframe, and something in the AT&T 3B family though dialup, courtesy of a friend of mine that worked at AT&T. About 3 months after the introduction to the 3B, a computer store in Atlanta opened literally up the street from me, called "The Byte Shop". I was there the day they opened, and they had to just about physically throw me out that night. I had no connections to people who had access to PDPs, P&E's, or other machines in that class. A fellow who turned into a good friend of mine at the Byte Shop got me a lot of time on IBM 360s and 370s at Cotton State Insurance, where he was a sysadmin. I learned Fortran there, and some long forgotten things about VM and CICS. Like many people, where the path split with the introduction of microcomputers, I took the micro path. I've layed hands on dozens of models of systems, manyof which I've forgotten. But there were the Poly-88's, IMSAIs (somewhere, a VDP-80 is looking for a home with me), PT systems (oh yea, wouldn't mind a 4 drive Helios drive cabinet for my Sol-20), Northstars, Apples, Sphere Research, just to name a few. At Georgia Tech, I spent easily hundreds and probalby thousands of hours in the terminal cluster, connected to a Cyber 74. Down the hall where Pr1mes, but I never had the right connection (people wise) to work on those. PCs came out, and I dropped the long loved Z80s, 6502s and 6800s to pursue this newer faster machine. Anyway, etc, etc, etc. Got into embedded systems, working with 8051s, 6809s, DSPs, RISC processors, all sorts of stuff. I've got two PDP-8 SBCs here, Bob Armstrongs kits. They both run, and you can do useful work (for certain values of useful :) ), but you can't run any kind of Unix on them (I have hundreds of hours on a PDP-8 desk model (I can't recall the suffix. /i? /a?). I think the problem was I was too young, back then, and failed to realize computing was splitting, and I should make a choice. Not having exposure to the PDP class machines, and Unix in general, didn't help. Can't choose what you didn't know. I don't think the way I went was wrong, by any means, but I defaulted into this branch, instead of choosing. And at times, I wish I had gone the other way. Unix is a better choice than DOS and Windows, and I could have been more involved at the Linux forefront. At this point in time, a PDP-11 is still cheaper than a Ferrari, and I can buy one piecemeal (unless I luck into someone disposing of one, and I don't have that kind of luck. I have a different kind of good luck, but it's not a type that involves people giving me highly desirable equipment). What I *do* know is that my PDP-11 should have a front panel. But it doesn't have to be red :) --jc

Designed and *BUILT*... it is, however, essentially unobtanium... I have a line on one, but only if/when the person currently in possession of it ever tires of it. Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | email: mbg at world.std.com | | Member of Technical Staff | megan at savaje.com | | SavaJe Technologies, Inc. | (s/ at /@/) | | 100 Apollo Drive | URL: http://world.std.com/~mbg/ | | Chelmsford, MA 01824 | "pdp-11 programmer - some assembler | | (978) 256 6521 (DEC '77-'98) | required." - mbg KB1FCA | +--------------------------------+-------------------------------------+

J.C. Wren wrote: There were only about four PDP 11/74 systems ever made! They use a bunch of modules and subsystems that were never used in any other systems, such as the IIST (Interprocessor Interrupt and Sanity Timer) and the MKA11 multi-port memory. The KB11-Cm CPU is similar to the common KB11-C used in the 11/70, but some modules are different, as is the backplane. The probability that you can find enough of this stuff to make an 11/74, or even just a single-processor subset of one, is vanishingly small. I don't think trolling eBay will ever turn up any of it. Are you sure you're really asking about the 11/74? If you want an 11/84 or 11/94, that's much more likely to happen.