From mboxrd@z Thu Jan 1 00:00:00 1970 From: clemc@ccc.com (Clem Cole) Date: Wed, 27 Dec 2017 16:51:54 -0500 Subject: [TUHS] Why did PDPs become so popular? In-Reply-To: References: Message-ID: You are mixing a couple of different stories I fear... If you want the full story get a copy of: Computer Engineering: A DEC View of Hardware Systems Design But a snap shot for this mailing list is this ... The PDP term was used by KO when he was funding Digital because the VC's the 60s did not believe that a computer company would succeed. But making things for the instrumentation market (Lincoln Labs, Livermore, *etc*.). This is how PDP-1 came to be. The PDP term was keep for the first 25 years (until the Vax and renaming of the PDP-10/PDP-20 to DECSystem 10/20). [The 1 begat the 6, 9, 15 an 10 families]. The concept of purchasing smaller system, was indeed true. This was the idea behind the >>mini-computer<< or *minimal computer* that Gordon Bell who lad left DEC temporarily to be a CMU Prof for a time began to explore. He took the idea and commercialized and the PDP-8 line was the first in that line. The 11 & 15 were full computer systems. DEC also made something called the PDP-16 'Register Transfer Modules' (RTMs) which was an attempt to make the small controller idea even more accessible, but the Intel microprocessor would eclipse them (I think I was the last group at CMU was talk a course using them. Another factoid, the predecessor to VHDL/Verilog and the like, ISPL and ISPS actually spit out 'code' for DEC RTM modules instead of gates). But the key point is that in 1975 dollars, a PDP-11/40 system that was good enough to run something like Sixth Edition of UNIX cost somewhere between $50k-$150k. This would have been much, much cheaper than say a PDP-10, or a equivilent IBM 'mainframe' size system which would have started above $1M. Clem On Wed, Dec 27, 2017 at 4:02 PM, Alec Muffett wrote: > I apologise if this is too far from the main topic, but I wanted to check > an urban legend. > > There is a story - as I have heard it told - that PDPs established their > place (and popularity) in the marketplace by pointedly *not* advertising > themselves as "computers", but instead as "programmed data processors". > > This was because - so the story goes - that everyone in corporations of > the time simply *knew* that "computers" came only from IBM, lived in big > datacentres, had million-dollar price-tags, and required extensive project > management to purchase; whereas nobody cared enough about a thing called a > "programmed data processor" to bother bikeshedding the > few-tens-or-hundreds-of-thousands-of-dollars purchase proposal to an > inevitable death. Thus, they flitted under the purchasing radar, and sold > like hotcakes. > > I wonder: does this story have substance, please? > > Aside from anything else: I draw parallels to the adoption of Linux by > Wall St, and the subsequent adoption of virtualisation / AWS by business - > now reflected in companies explaining to ISO27001 auditors that "well, we > don't actually possess any physical servers..." > > - alec > > -- > http://dropsafe.crypticide.com/aboutalecm > -------------- next part -------------- An HTML attachment was scrubbed... URL: