In article <8896@fy.sei.cmu.edu>, ae@sei.cmu.edu (Arthur Evans) writes: > All DEC computers before the VAX are named PDP-n for some value of n. > Why PDP? > > I've always understood that it stood for Programmed Digital Processor. > Does that ring a bell? > Programmed Data Processor. Remember back to the dim ages of computers. The were VERY big and VERY costly. So costly that even major corporations could only afford to rent them. At the time, Ken O and his company, Digital, were building board level products (I have an early catalog before the PDP days and it's fascinating!). After a successful bout of manufacturing logic boards and such (remember flip chips? -- cards that contained flip flop circuits before ICs?), Ken wanted to build a computer -- one he had seen in a vision he had after standing in a canoe and hitting his head on the thwart. This vision was a low cost mini-computer that was affordable and personal -- people could actually touch it and get it to do real work! Now at the time, there were very few companies that made computers, and they spent megabucks. Computers were truely out of reach. Anyways, the board called no joy, and told him that there was no way that they could ever hope to compete with big blue and friends, and that the idea of an affordable computer that interfaced with people was the result of too much time spend in the Lincoln Labs doing circuit design on the TX-0 (Ken's computer at MIT). They figured that no one would buy a computer that was affordable, since everyone know that computers were unaffordable. Hence the name PDP. It wasn't a computer - it was a PDP! Get it. Anyways that's how the story goes. An excellent history of computers, especially those relating to DEC and MIT, can be found in the book _Computer Engineering: A DEC View of Hardware Systems Design_ which is available from Digital Press and is extremely fascinating. From the book we get comments - that may be more accurate - such as: "Although DEC was formed in 1957 with the explict goal of constructing computers, the company's first computer, the PDP-1 was not demonstrated until almost two years later. The principle backer of DEC, American Research and Development headed by General Georges F. Doriot, was somewhat skeptical that a computer company could be successful. They were enthusiastic, however, about the business possibilities in logic modules for laboratory and system use, and they felt that the plan to build computers should be conditional upon building a solid base in the module business." Which explains systems like the LINCs (Laboratory Instrument Computer). DEC had been building little boxes used in labs that had patch cords to connect the boexes togeter into functional circuits. Data processors that could be PROGRAMMED instead of wired would be very attractive to these customers, all 50 of whom never really realized they were buying a computer and launching the world on the real "computer revolution". The first customer Bolt, Beranek, and Newman, a consulting firm in Cambridge. In November 1960 the first machine, the PDP-1/B was delivered. A total of 50 were built. They had unheard of features such as a CRT and a TTY console. The price was $120K with a paper tape reader/punch, TTY and 4K-words and was designed for lab control applications, message switching, an "time-sharing". Check out the above book for further history and trivia -- highly recommended. -- ================================================================================ Dan Shoop UUCP: ...uunet!spcssi!shoop Manager of Systems Support Internet: shoop@spcssi.sequor.com Security Pacific Software Services AT&Tnet: 212.425.0200 The Sequor Group ICBMnet: 40 45 N / 73 30 W ================================================================================ Your standard disclaimer here. Nuke 'um 'til they glow, then shoot 'um in the dark. >successful bout of manufacturing logic boards and such (remember flip chips? -- >cards that contained flip flop circuits before ICs?) This is a little misleading -- "flip chip" just implies packaging -- a board of one of a few sizes, and with edge connectors of a certain size. The first PDP's used other board packages. I'm not sure where the transition fell, but certainly the 8 used Flip Chips, and the 1 didn't. Up until the recent, bus-of-the-week VAXes, everything common* was on Flip Chips -- 8's, 11's, 20's, etc. I have a board from a 20 on my wall here, as well as an 11/03 cpu and an mm11 plane, and sometimes people will come in and call all three of them Unibus cards, when *none* of them is. >An excellent history of computers, especially those relating to DEC and MIT, >can be found in the book _Computer Engineering: A DEC View of Hardware Systems >Design_ which is available from Digital Press and is extremely fascinating. * things like the vt78 and pdt's excepted, of course. -- datri@convex.com The following items are DEC PDP-11 peripherals that are for sale: Prices are guestimates only; nothing is written in concrete :-) !! All items are UNIBUS unless otherwise noted. All items are made by DEC unless otherwise noted. 1 - KE11-B Extended Arithmetic Element (EAE). Single hex width board. asking: $25 4 - DL11-E's. Serial interface with modem control. Two tested and working, one unknown, one non-DEC(has own manual and schematics tho) asking: $20 each 1 - DECMATE I word processor. Has 1 dual RX02 drive, and VT100 cabinet with all control electronics. I believe it has 2 serial ports built into it. With manual and system disk. [PDP-8 based chipset] asking: $85 (not shippable - you pick up) 2 - Falcon Plus CPU Boards (M7676). New. Has 1 parallel, 2 serial channels, on board ram (32KB) and 4KB rom monitor. Will run stand alone or in a QBUS backplane. Monitor ROM's will boot via TU58 or RX02 (RXV21 controller). asking: $40 ea 1 - Falcon Board (M8063). 2 serial, 1 parallel, sockets for 32KB RAM/PROM, QBUS. asking: $25 2 - RK05A 2.5Mb removable disc drives. Rebuilt units myself (new filters, oiled bearings, general cleaning, head alignment, servo alignment). With BC11 cable, rack slides. asking: $65 each (not shippable - you pick up) 1 - DR11-C DEC 16 bit parallel in/out interface. Modules M786, M105, M7820 asking: $10 1 - DR11-B DMA 16 bit parallel I/O interface. Unknown condition. Has own system unit and loopback backplane connector. asking: $15 Terms and conditions of sale: All items are believed to be working (unless noted otherwise) but are sold as-is, no gurantees. You pay shipping (note some items are too big/heavy for UPS to ship, so you will need to arrange the shipping - i.e. you pick it up or have it picked up.) CASH or certified bank check only, please! Prices are suggestions, IF you feel they are out of line, EMAIL your comments to me directly - DON'T WASTE NET BANDWIDTH flaming me! (All flames are directed to /dev/null anyway, so don't waste your time! ;-] ) Please send bids/replys to me via E-MAIL - use the phone as a last resort only - PLEASE! Also, include your daytime phone number so I can reach you if necessary. -- John Gibbons Allen-Bradley Company Highland Heights, Ohio "Welcome My Son, Welcome To The Machine" - Pink Floyd I can be reached at: {uunet|pyramid|decvax|cwjcc} !abvax.icd.ab.com!astro.decnet!gibbonsj or some variation of { ? } gibbonsj%astro.decnet@abvax.icd.ab.com internet: gibbonsj%iccgcc.decnet@consrt.rok.com If all else fails -> voice: (216) 646-3811 Of all the things I've lost, I miss my mind the most...