DEC and the PiDP-11 

I should probably mention calling it America Standard Code 2 was intended to be a joke. It would seem its a joke only me and one other person found funny. One error that was real and not a joke, that Lawrence pointed out was when talking about core memory, I explained it wrong. It's not that the ring is magnetised or not to represent 0 or 1, its the direction of flux is used to determine 0 or 1 the ring is always magnetised.

As someone who is blind from birth, I will always remember this company for creating the DEC Talk. One of the first, and definitely one of the best, speech synthesizers. Back in the 70s. They were extremely expensive in the beginning, but they got better and cheaper. Evolving into an internal card, for PC, serial external device, and finally simply software. One of my favorite synthesize voices ever. An early version of it may be heard if you ever listen to Stephen Hawking speak. I don't know the story behind it, but I find it hard to believe it was a business case based on profit potential

I worked for Ken from 1993 to 2000. I loved every minute of it.

DEC changed the world. By inventing the mini computer, they started the "embedded" computing revolution: computers that are used to control machines or chemical plants instead of merely being used to crunch numbers for researchers or accountants. Now, there are innumerably more "embedded" computers than regular ones, even if you count a smartphone as a regular computer. And they were instrumental in developing UNIX. Another great contribution that changed the world, as it has become the most widely used OS.

Another nice thing about core memory which I took advantage of (as a service engineer) was, if your computer had an I/O problem so it couldn’t load any code, you could take its memory boards over to another computer of the same model, load the I/O diagnostics, bring them back and plug them in and presto! You could run diags on the broken computer to find out why it was broke! Try doing that with DRAM!!

What a great video and summary. I worked for DEC from 1987 to 1999 (so ended up working for Compaq), and it still the best company I ever worked for. Not only from a tech point of view, but also the way we did things. We just did it as a team. That was the heritage and spirit Ken brought in. We all stood together, something I miss nowadays, to be honest. Today, ~25 years after leaving, I still know my badge number, and I’m still proud that I was part of DEC for over a decade. DECCIE for life! Too bad I can’t tell it to Ken

I used to work for SCI Systems in Huntsville, AL in the mid-1980s. They made core memories which were still used by the military and NASA due to their resistance to radiation and nuclear micro-burst. The cores had become so tiny, they looked like pepper in your hand. One disadvantage of early core memories is when you read the value of a bit (1 or 0), you erased it in the process. So you had to read each bit and immediately write it back.

Thank you for making me feel very old, my first job (1975) was booting up the PDP8/E in the morning, this required selecting several 12 bit words on the orange & yellow piano keys and then lifting the Deposit key, when all were in memory then Run - this was called the RIM loader. It should be noted how heavy these things were, it was a three man job to lift one of then into a 19 inch rack.

My dad was a field service engineer for DEC throughout the 80s and 90s. He loved that job. I remember going to with with him especially when he had a weekend shift. It was mostly VAXen at that time but I was on awe at the equipment. I also remember that every year, the company rented an amusement park for all the employees and family.

I worked for DEC just before the compaq buyout. I find I keep referring to the culture they had created there - even now. So one of the stories was about the deskpads - this was back in the day when you had a big deskpad on your desk. One of the people were mentioning when they started at DEC, they got to their desk, here was a new deskpad - turn over one flap and it described how to introduce yourself over the phone etc. The other flap just had one message - "Everybody makes mistakes". I have never really worked anywhere else where almost everyone left their ego at the door - it was all about the learning and the outcomes.

Excellent video, thanks. Worked on pdp 11/70s years ago. When I mention DEC or digital to some of my younger colleagues, I get a blank look! DEC played an instrumental role in providing "computer" systems to smaller businesses and organisations in the days when only big business and government could afford mainframes. Their VMS operating system is still on the go (supported by HP) as many core applications were developed on pdp's and then VAX systems.

For years in the 1970's I ran PDP8's for NOAA doing hydrographic work. The manual wanted the power supplies set to 5.0v and 12.0v. Ran much better at 5.3v. The 12v side was high enough. Stout machines. Noisy, but generally reliable (like decades). Thanks for the trip down memory lane 🙃

The PDP-11 changed my life. I was lucky enough to attend a high school that had one in 1980, and a high school teacher that was happy to take anyone interested in how it worked under his wing. RIP Robert Russell. You were a mensch. Thank you.

As a computer professional for the past 28 years, I’m saddened that I missed out on this age of progress. Love learning of these stories through your videos. Great work! And Thank You!

Worked for DEC from 87-94, one of the most memorable jobs I've ever had and some of the smartest interesting people I've ever worked with. The whole company was like a family. Working for DEC was like a college education. Really sad to see the way it ended up.

I first used a PDP11/45 in 1988. The login command is 'hello'. These things were payroll and accounting machines back in the shop is working. I was a Vax guy managing the three 11/750 Vaxes and 8 more remote Vaxes. 2400 modems back then works just as well for console mode tty. I missed those days..

I owe so much to DEC for my understanding of computer technology. In the mid-60s, I somehow got myself on the DEC mail list to receive books like their processor handbooks. I studied these cover to cover, and I was in 6th grade at the time. When I worked at UCC in the early-70s, we used PDP-8 machines as the backbone of a world-wide network to remotely access our mainframes. A PDP-9, and later a PDP-10 provided terminal access called "FAS-BAC". It allowed running programs on the PDP-10 or on the many IBM 360 and UNIVAC 1108 mainframes. It also gave us email to others in the company and to our customers. I was also able to enter programs from the light panel, a technique I was able apply to the mainframes. In my computer science classes, learning machine code programming, the PDP-11 machine code was like a wet-dream compared to the 360 or 1108 machine codes. Thank you DEC.

Thanks for the great retrospective on the early days of DEC. My dad worked there for most of his career and I owe my own career in software as a result to DEC. DIGITAL maybe gone but not forgotten. Looking forward to the Alpha video at some point. Thanks again.

I knew quite a bit about Data General from reading Soul of A New Machine. Given DEC was framed as the underdog's competition in that book, I allowed myself to believe it was just that. Glad you covered the ways Ken made DEC unique. Showed me I was wrong. Glad I now know and why.

I learned my first programming in high school. We had terminals (DECwriters) that connected via an acoustic coupler to a PDP-11 in an administration building a couple towns over. The OS was RSTS/e and the language was APL. Once home computers and modems became a thing, we'd log in at night and run chat programs we wrote. It was an early taste of what became the internet. Communicating with people in real time, live, no matter how far away. Eventually, schools went to Apple computers and the need for a network of terminals went away. I was offered the PDP-11 for free. I went to look at it and with the hard drives, it was the size of a refrigerator. I declined.

I worked at DEC in the 80's. I Still remember my employee badge number and I'm a member of DCU Credit Union.

Thanks for making this video. I worked for DEC from 1977 to 1979, and again from 1981 to 1987. This brought back a lot of fond memories. DEC was the best company to work for. The employee benefits were fantastic and there were lots of opportunities for upward mobility, which was encouraged. Ken Olsen was indeed ahead of his time both technologically and socially. The first computer I worked on was the PDP-11/40, which was used as a front end to the DEC-10 and 20. There were many PDP-11 operating systems but the most formidable was the PAL-11 paper tape system. You had to load and then punch one or more paper tapes on each edit for each file of the program, and again for each assembly and link step. Good fun! The DEC-10/20 line used a 36 bit word and the CPU used ECL - a very sensitive logic unlike TTL. It was more difficult to work on. Finding problems in these circuits could take days, weeks, or even months. Try googling an image of a PDP-10 CPU backplane to get the idea. On my second term of employment I wrote firmware for the VT240 video terminal and then went on to lead a group writing VMS printer drivers for the Postscript printers that replaced older technology of the period. I miss those days. We had great fun designing cutting edge products for a great company!

As an engineering student at the University of Hawaii in early 70's my class using the PDP 10 at MIT that was running a math analysis application remotely through what was then the Arpanet. It worked out quite well cause of the 6-hour time difference.

DEC was an outlier in what we would now call Stakeholder Capitalism. Companies need to build products for a profit, but also need to consider their Internal and External Stakeholders. Long after DEC set the example, its has taken almost 30 years to see other companies adopting similar stances. And I would argue, none have reached the scale that DEC had in its heyday.

Very nostalgic for me. I was a user of a DEC PDP 11/70 in the 70's at a manufacturing plant, that was later replaced by a VAX/VMS cluster. DCL was a very powerful tool.

Nicely done. As a new hire at a relatively new company (Atari in 1976) I was to put together the second computer system they had at that facility, a second (third?) hand PDP 11/20 which had 20K of core memory, two 8" floppy disk drives and a paper tape reader/punch. The other computer they had was a PDP 11/05 which I believe had 16K of semiconductor memory and also two 8" floppy disk drives and a paper tape reader/punch. A couple years later we picked up a used 11/03. All running RT-11. They were used as our only machines until we bought the first of many VAX in 1981. Look forward to your video about the VAX.

Fellow nerd from Oregon, USA here. I love your videos! A great balance of informative and sometimes hilarious snark! Thanks again for a wonderful peek into DEC.

I loved being a DEC engineer from 1983 to 1988 - Fabulous server and well loved by customers, reliable too.

They were a great machine. We had one of these at my high school and I was one of the lucky kids who got to look after it. I could flick those switches to 173101 octal and reboot it faster than you would believe. 😀

At Univ. of New Orleans, we had an X-ray crystallography servo-table driven by PDP-8s. We had a PDP-10 using the KA-10 series. I was a student operator of it. Later the university upgraded that to a KI-10, and finally a KL-10. That was a bloody fast, powerful system. I had a PDP-11/15 in my chemistry lab. Finished my dissertation research doing real-time data gathering with it. Spent the next 12 years after my doctorate working as a device-driver writer for PDP-11s. My employer, TANO, sold a lot of PDP-11/40s and later, 11/44s, for oil-and-gas pipeline control systems that monitored sensors in the pipeline to track what was flowing through it. That machine was a true delight to program in MAC assembler, though we also had a decent FORTRAN compiler. The thing we really liked about the 11/44 was that it had floating point ability built in to the CPU chip rather than available through an external card, and that its memory management abilities included the ability to handle up to either 2 MB or 4 MB, I forget which. In the 1970s, either one was a LOT of memory. I loved those machines until VAXen came onto the scene. The 11/44 was a good replacement for the 11/70. We never ran UNIX on any of the 11s, though. We used RSX-11M most often, but the business office had a RSTS-E-9.

Thanks for the enjoyable trip down memory lane. Started on PDP-11 and went to DEC JIT plant in Galway IRE in the early 1990s to benchmark a Vax9000. Great memories, great people, great times. The company I work for today still uses VMS and good to see VSI have it running on x86 architecture. Did many a VAX to AXP to IA64 migrations. Looking forward to your next video.

It was indeed an exciting time to be a computer nerd. Minicomputer companies were run by engineers, not MBAs. Sales pitches stressed obscure technical features such as a process exchange time that was a few nanoseconds quicker than the competition, or loadable microcode. For younger folks curious about that period, I'd recommend reading "The Soul of a New Machine" by Tracy Kidder. Mr. Kidder was a journalist, not a computer geek, so his explanations are accessible to any reader. I especially related to his chapter on microcoders. I've never written microcode myself, but as a CPU technician I had to learn how to read it and single-step it. It's a whole 'nother world in there.

That's such a beautiful computer (replica). I'd love to get my hands on one of those, proper switches are just so satisfying.

In collage I worked on PDP-8 (Straight) serial number 7 and several PDP-8L's and a PDP-12. After collage want on to work on a Decsystem 10. I still have my DECstation Installation Kit screwdriver. It says "PDP8 more than 40,00 installed worldwide". It was a great era in computing!

Awesome video, this first computer we used at school was a terminal connected to the Hatfield Poly PDP11. Every program was paper tape or punch card. We then got a BBC and a couple of RML380Zs. Good times back in the late 70s and early 80s. :)

I was an electronic engineer at DEC in Reading UK in the late 80s, early 90's. It was a fabulous company to work for and I loved every minute of my time there.

In 1978 at 17 years old I programmed a PDP11 to manage band candy sales. My math teacher took the programs to a junior college each night. I was hooked and 44 years later I'm still in the game. Thanks DEC and Mr. Hermann!

Great video, brought back many memories of various pdp11s. In those days quite a lot of programming was in assembler and the '11 had a very elegant and orthogonal instruction set which was very rasy to learn and use. So much better than what intel foisted on the world with the 8086

I worked for DEC in the early 80's. One of the best tech jobs I ever had!

Seeing all this DEC love makes me really happy. My mom worked for the company throughout most of my childhood, and when DEC was bought out, it was like there was a death in the family.

Also great in gaming history, the PDP-1 had what is arguably one of the very first _video_ games, Spacewar. Also, Tetris was programmed on an Electronika 60, a Russian PDP-11 clone.

Drove by a DCU branch for years, and never realized the word "Digital" in their name was in reference to DEC, and not "e-banking". Thanks for the tidbit.

As a engineer in a highly competitive and stressful market, I think I could get along with ken, much like my first boss in my current career, always seems cheerful and encourages growth within his team ... but no slouch either constantly driving innovation (he worked at DEC as well)

Anyone who's programmed in PDP-11 assembler knows just what an elegant instruction set it had. It was a joy to program. Nova and HP-1000 were like wind up toys in comparison to the 11.

I used to have a PDP 11/23 with 2 RL drives in my room in a half height rack. I lived on the 3rd floor with no elevator, and on top of this I had to haul the thing home by tram, it was quite an operation all in all, but it worked flawlessly one put back together. I had to clean it up as it had been outside a computer labs loading dock for a week or two and got rained on.

Brilliant video! Thanks for the history lesson. DEC's PDP machines feature heavily in MIT's 1950-60s computing/AI lab story, "Hackers".

Fascinating! I had no idea DEC was so ahead of the curve socially - Now I want to build a PiDP11!

My first experience of programming was on a PDP 11/23 (I think. It was 40-odd years ago) using machine code which was input one word at a time direct into memory through the toggle switches on the front panel, and then saved to a punched paper tape. Oh the fun you had when the centre of the paper tape fell out and the whole reel unravelled around your feet . I also remember using magnetic core memory which was loaded from paper tape and then held the programme almost indefinitely. One lesser known characteristic of magnetic core is that it was resistant to electro magnetic pulses so was used in a number of military applications. I later worked on the DEC VAX 780 series of computers which had the luxury of a multi-user operating system, multiple processors, magnetic tape drives and 14 inch 20 surface multi-platter removable hard disk packs... all programmed in languages like Fortran. Such fun 😁

Hi. I as an West German engineer got trained in Kiew in 1982 as service man for the CM4.. It was a very huge deal around a steel production in Kursk. The automation was done via Swedish ASEA, whom I worked for. The knew that DEC had sold their plans plus old manifacturing machines to the only industrial computer manufacturer of the UDSSR. While our 6 weeks training we meet al the leading staff of that company... They even showed us their work in progress ( the VAX)... All that cloning has been, to my best knowledge, made with/by DEC themselves, just in the times before the embargo.... These guys trained us to repair the computers on TTL-chip level, using a single counter that toggled the micro-code puls. Very nice competed people witch struggled with their low quality produced hw. (f.x. I never before saw corroded "golden" wrap pins) Since these experiences in younger times I don't trust our daily press blabla anymore..

I remember the PDP11 as the system that controlled the auction clocks at the largest flower auction in the world in the Netherlands in the 80's.

Worked as Field Service Engineer from 1980 to 1994. DEC was known as the best company to work for in the USA. I first learned PDP-11 architecture in the Navy. Cecil Field used about 15 PDP 11/45's to run 3 S3 A Viking Anti submarine Warfare flight simulators. After that, straight into a job with DEC. I became the VAX specialist, then onto Alpha. Two of the best jobs I can imagine. Back then there was at least one company that actually cared about its employees. And its customers, almost to a fault. Sadly, I don't think any company like it exists today. Thanks for the video!

Had the opportunity to meet Ken when I was working at DEC in the late 80s as a lowly service tech. Such a warm and wonderful person. He would deliberately avoid the sales and management folks and would seek out the engineers. Lots of stories, including a few about the early days and avoiding the use of "Computer' at all costs! The only DEC event I ever attended that was alcohol-free....

Talk to any ex-dec employee including myself and they will all say Ken was a wonderful person. There are many stories about his kindness and care for his employees. From the time I started in 1976 and left in 93, he refused to lay anyone off even though the company had grown to over 100,000 employees. He was so humble it is true tat he drove around in a Ford Maverick and he wore those elbow patches on his suit sleeves. No alcohol at the company picnic either. Just a fantastic place to work. We had everything at our facility, company nurse, full cafeteria, credit union and rep's for insurance. So, you could do banking and all your insurance needs right there in the plant. I will also remember the fleet of helicopters they had that flew employees all over Mass. It as just a wonderful atmosphere to work in and much of that had to do with Ken himself. Then of course he was not the media or wall street darling as the 90's rolled in and he was forced out. That is the day, as they say, the music died for me and a whole host of employees as a new era was ushered in being led by Bob, the Butcher, Palmer who sliced and diced the entire company, selling off almost all the divisions. Those that do not know DEC don't realize they made every part of the computer system. Terminals, printers, storage options like hard drives and tape backup as well as creating their own chips and boards. I could go on and on but I will never forget in 1976 when I started I was amazed that I could actually send "mail" via a terminal to any other DEC employee no matter if they were located in the US or in Europe. This was light years before "email". DEC was doing this 30 years before on their internal networks. Still have some stuff from my days there and this brings back a lot of memories.

Great video , I had the pleasure of working with DEC for 14 years .. covered all the early consoles , PDP8's PDP11's, VAX.. this brought it all back for me .. Sigh

When I was in the Navy, we had a PDP-1170 that was used for message processing. It ran RSX11. Loved the blinking lights. It was lots of fun to work with.

My connection with DEC is on two fronts. In 1992, I was a cook at TGIFridays. My favorite customer was a DEC employee that looked like Chuck Norris. He tipped great. The other connection was around the same time. I was connecting to BBS systems by modem. On one BBS, I found a dialing sequencer similar to the one in the movie War Games. One night of dialing, I found a modem connection to DEC. So, I logged in and started snooping. Fearing FBI agents would be knocking on my door any minute, I stayed on for a few minutes, then got off and stayed off for a week. In hind sight, I realize I had only connected to some primitive online store, but it was cool and scary to connect to another computer without them knowing who I was.

Such good memories, first at university EE dept we used the PDP8 amongst others, then in my first company we bought truckloads of PDP11/34 for field data acquisition and VAXes in our data interpretation centers.

I remember the supremely satisfying sound the VT100 terminal Return key made when you hit it, when I was at University. Thanks for putting this video together.

I was an EE/CS student from '78 at UNSW in Australia. We had an 11/70 running the CS department with UNIX (it was very early days and UNSW was a UNIX pioneer). It was such a lovely machine but hopelessly overloaded. I was so familiar with all aspects of that PDP-11. Once it failed and the whole department was at a standstill. We were waiting for the DEC engineer to show up and fix it and I decided to do something about this... The machine was made entirely from discrete logic and we had all the schematics - so I set about analysing what was wrong by first loading code through the frontpanel switches and localising the fault (DEC diagnostics were not really that helpful). After that, it was the CRO and logic probe. Within a few hours I had tracked the problem to a faulty XOR gate in the CPU. These were available in the school store and I managed to convince everyone that I knew what I was doing - so I set to work with the soldering iron to replace it. The machine was up and going again long before the DEC engineer appeared. The PDP/11 was such a nice piece of hardware - with a straightforward design that an undergrad could understand. Looking back, I am still amazed that I convinced the academics to let me fiddle about on their precious machine. I suspect that these days, they wouldn't even be able to overcome the "work safety" dramas associated with pushing out the CPU sub-cabinet...

I worked for DEC UK. In today's tech world we use a lot of things, products, concepts that DEC originated, co-originated with universities, commercialised, productised or in other ways enabled. I'm talking about various data storage technologies, storage virtualisation, networking, clustering, data centre virtualisation, RISC processors, multi-core processors, speech tech, multimedia tech, power control, operating systems - and many more things which DEC either originated, co-originated, enabled, advanced, commercialised or productised. In the mid-late 1980s DEC was looking like it might even become top dog in the computer business, and working there you truly felt valued and looked after. But a series of missed boats and bad decisions meant that the company began to slide in the early 1990s. By the mid 1990s a lot of long term employees were in shock because DEC was disbanding complete departments at almost zero notice and the asset strippers were in selling off chunks of the corporation (networks dvision, storage devision etc) and DEC was behaving just like companies have to when they are under existential threat. There's a great lesson there for anyone today in a large corporate that is doing well and can cosset its employees. Multi-core processors is an interesting one - the Multi-core Intel processor you may well be using right now, might owe its existence to DEC. The DEC Alpha processor had multicore processing in about 1994 or so. When they started asset stripping DEC, one of the things to get sold off was the semi-conductor division, which designed and fabricated Alpha processors. The buyer was Intel. Another interesting thing to reflect on is the striking number of design similarities beteen DEC's VMS operating system and early versions of Microsoft's Windows NT. Yes, DEC was an interesting company - a fairly short lifetime compared to - say IBM or HP - but it's contribution to modern information technology cannot be overstated.

I was introduced to the DEC PDP 11 series in 1983 when I went to work for Rockwell International as a field service tech and installer of the Rockwell Galaxy ACD (Automatic Call Distributor) phone system used in large call centers. Continental Airlines bought the first one in '73 if I remember correctly and used it all the way to '96. Now those rows of equipment racks are replaced by one small tower or less with the advent of VOIP and powerful processors..

My father worked for AT&T/Bell Network for many years - I remember him taking me to the central office in north Florida, and seeing PDP-11s there. The Bell System used them for recording and processing long distance billing. I remember the colored "piano switches" and flashing lights...

Ahh… The good old days. We were an OEM networking company in the late 70’s that standardized on the PDP 11/40 as network nodes. Great company and great products

I remember getting a call out on a PDP-11 that was running a milling machine it was making the landing gear for some fighter it was built like tank, after wading knee deep in metal shaving to the cabinet I cleaned all the cards and replaced the 12" floppy drive and back in business again .. ah the joys of field service

Wow! Everyone has a story! Here's mine; When I left the Army in '82 I hired on with TRT Telecommunications in Ft. Lauderdale, FL. We had a very cool large computer room and at the center was the Telex Exchange. It was an Eltex II from Fredrick Electronics and was powered by two PDP-11/70's. With all the blinky lights and big redundant mag tapes going it was like working on the bridge of some 60's era scifi starship. It's all gone now, but what fun it was! That era came and went so fast. Thanks for posting this vid, it brought back many fine memories.

I was fortunate to work for DEC's competitor Data General from 1977 to 1983. I was trained on a PDP/11 in college and wanted a job at DEC and they gave me an offer, but it was in a region I didn't want so off to DG I went. Those were awesome times with explosive growth in minicomputer sales, but the PC was starting to infiltrate the workplace by the time I left that segment of the industry. Those companies were too in love with their "babies" and unwilling to accept the possibility a PC-grade machine could impact them in a measurable way. Obviously, they became the new dinosaurs; the same fate as many of the mainframe manufacturers they replaced a couple of decades earlier.

Probably the best 10 years of my career. I started in 1981 as a Sr Cost Accountant in the Springfield Ma plant where tape and disk drives are manufactured. Helped start up the Greenville SC PWB plant before returning to Springfield where I was promoted to Cost Accounting Mgr. Finished my career as a sales rep in Knoxville, TN. Unique company, unique products, unique culture.

I learned most of my earliest programming on a PDP-8/E that my High School bought in (I think) 1971. I then went on to do A LOT of PDP-11 programming at the MIT Model RR Club (TMRC), where eventually there were 3 PDP-11s under the layout running programs that controlled various parts. They relied on the fact that they were core memory and didn't need to be reloaded each time the layout was powered on, they just came up running (well, usually). I now have a basement full of DEC computers (and a few non-DEC), but none of them are regularly working, I keep hoping to have the time and energy on getting them back. Two PDP-8s, several PDP-11s and myriad LSI-11s and MicroVAX machines, along with a huge set of spare parts.

I got a job offer from DEC in Vermont in 1979 (with three increasing salary offers, no less), and like an idiot turned them down to work at a very unsatisfying electronics company that I didn't stay with for long. Even though DEC died before I would have retired, I still very much regret missing out on the (presumed) fun of working for them. It was a PDP-8/I that I learned programming on, in college. This video has inspired me to buy a PiDP-11 kit to use as a front end for my home security system, ensuring that the system will be completely opaque to anyone other than me. 🙂

When I went to junior college we had a lab with a PDP/11. I remember using the different terminals around campus and the times someone in the lab would shut down the computer without telling anyone. It was still cool to get to use a computer at the time and you had to sign up to be on a terminal in the lab and sign off for the next person to use it.

You're right about Core memory retaining data. I have a prototype DG Nova with core. A project we did was to try and read-back the contents. Took a few months of research and when it was dumped, it had part of a Fortran Linker still in it. Read date was early Sept 2020. Much as we can tell, last time the DG was run was 1978. Love my pdp11's. So your video warms my heart greatly. I have a pidp8 and 70 also. One day I'll get sufficient tu-its and build them.

That PiDP would look great near your front door at Christmas. DEC the halls and all that.

My first computer field service job was servicing the PDP-8 and PDP-11. They were in colleges around the state. What an experience … 😊

We love good guy Ken Olsen :')

I love the light hearted presentation you did, Thank you for posting.

I learned system programming on a PDP-1140 & PDP-1170 @ University of Maryland College Park in the late 70's. I STILL have my PDP11 Processor Handbook & Periphal Handbook. It starreted me on a 40+ year as an embedded systems programmer. A GREAT machine!

I was too busy listening to the music to notice what you did wrong. Thank's for the link!🎧

10:36 Differences between PDP-11 models mainly had to do with * Instruction-set extensions, e.g. the availability of floating-point hardware * What kind of expansion bus they had -- mainly UNIBUS to begin with, I think some Q-BUS models came later * How much physical RAM they could address. Remember the instruction set only had 16-bit addressing, while actual PDP-11 models came with 16-bit, 18-bit or 22-bit physical addresses. You thought the 8086/80286 segmentation model was tricky to deal with?

Well, good presentation. I worked for DEC for many many years. Supported TOPS, VAX/VMS, ALPHA, System 5, OSF/1, OpenVMS, most programming languages, hardware support, engineering, networking, clusters, etc. Ricky from IBM, Ret formerly of DEC

Worked at DEC between 1969 and 1960, which I consider the golden era. You have done a good job given the time and I think fairly accurate. I hope you mention the visionary at DEC Gordon Bell in your next video. There is a book I can recommend "DEC is Dead long live DEC". It Should be required reading in Business Schools on the etablishment and impact of company culture.

Awesome video! Been thinking of building one of those PiDPs for a while, looks like a relatively easy build so might pick one up! Thanks!

I was a field service engineer for dec, ‘79 thru ‘91. DECsystems and VAXen

In about 1968, the company I worked for at the time sent me on a one week PDP8 assembler programming course. I probably learnt more in that week than in the whole of my electronics degree course. Despite having had no previous knowledge about computers, I came home at the end of that week completely spellbound - everything was so clear. I understood not only the software, but also the hardware. So I decided to design and build my own! I didn't stick to the PDP8 design, but "improved" it (with hindsight, a big mistake because of the lack of software). For example, mine had 4 accumulators as compared to the one of the PDP8. It took me two years, working evenings and weekends. Sadly, it was out of date before it was finished, but there weren't many people around in the 60's with their own computer and I learnt a lot from the project.

I was smacked with nostalgia when you showed the pdp-8, with its autumnal color theme. Flip, step, flip step, on and on to program the loader for the paper tape reader. The orange three ring binders with documentation in the one shot also brought back memories. I wish you would have shown the wire wrap rat’s nest inside the drive units. My experience with pdps was in industrial control systems. They were everywhere, once upon a time.

Wonderful video! I started working in my university as administrator for a VAX 11-750 in 1986 and there were one PDP-11 but I didn't use. We planned to buy a VAX-9000 but thankfully workstations were beginning and migrate to DEC Ultrix on high resolution screens and then to Linux on PCs... really a wonderful time... connecting the VAX to worldwide DECNET OSI network... then the Ultrix machines to Internet (at 2400 bps... quite a high speed for a whole university! hehe) the first BBS (bulletin board systems) the Usenet News, Gopher and finally WWW! I thank God for being in the right place at the right time... what a wonderful times we lived! Looking forward to see the VAX and Alpha videos! keep on rocking!

Old Timer Here! The first ever "computer" I ever used was a DECwriter terminal. I worked for a backwater CitiBank subsidiary in Memphis in 1978 and when they installed the terminal, I was chosen to be the operator because I was the youngest and had used a pocket calculator before! The DECwriter was a dumb terminal consisting of a keyboard and a dot matrix pin-fed printer. We connected to the Citi mainframe in NY via a pair of 300 baud modems, each the size of a small chest freezer - lots of blinking lights. I remember it used an acoustic coupler, like a cradle for the phone receiver. My mom thought it was so cool that her son "worked with computers". Now, everyone has one in their pocket. Gosh, I'm old.

I started working initially on pdp 11/03's and moved up to pdp 11/34's. The pdp 11/34's had RK-07 (rock crusher) hard drives. These were later upgraded to Fujitsu 30-30 multi-plater (Winchester) hard drives. Then the pdp 11/73's came out. I worked with RT-11 (real time) and RSM-11M (multi-user multi-tasking). These were awesome machines of their day, but today the typical laptop can run circles around them. And, yes, I worked on VAX-VMS systems too. (I had one dedicated to me for almost a year.)

I worked at DEC in Los Angeles for 15 years on VAX/OpenVMS, Alpha OpenVMS, OPS5, ULTRIX, etc. VMS Partner, programmer, Systems Engineer, etc. DEC Net, Clusters, etc. I have pictures of myself with Ken Olsen at the Old Mill. Did some work on Tops10 and Tops20. When Compaq purchased DEC I left and went to IBM for 17 years as a Systems Engineer / Programmer/ Storage Engineer/ Network Engineer. DEC was a terrific place to work, to bad we were sold out. Have picture of myself and Ken Olsen and pictures of him again handing me a collector grade map of the world. Ken was a collector of old and rare maps. I was part of a group that raised funds to purchase and present to Ken this way cool map of the world. Ricky from IBM, Ret

My father worked at DEC from 1962 to 1996. He was a designer on the PDP-6 and the lead architect and designer of the PDP-10. Digital was certainly a major part of my childhood. I remember wandering around the old mill building in Maynard; I mostly recall that it was dusty.

In the late 70s our school had an enlarged PDP4/7 hybrid that had been donated to it by the Harwell nuclear research place in the UK. 64K of 18 bit words, A couple of Dec-tape drives, a larger magnetic tape drive, a KSR-35 teletype, a 'high speed' paper tape reader and one of those circular VDU things that we never got to work. My A-level computer science exam project was a simple word processor written in PDP-4 machine language. Heaven knows how they managed to mark it(!)

This is an awesome video, I am looking forward to the vax and alpha videos. I used to have a pair of alpha servers first running nt3.51 nt for alpha, and later running lotus notes server on Linux. I loved the alpha boxes so much and I often wanted a pop-11 for at home but haven’t hot one yet

Thanks for the video, saw the dual-door floppy I was trying to remember for a comment on another video about the complete BYTE collection, sweet thanks. Also there is a cool video about the DEC engineer that went on to create Windows NT. Strange how Dec was at the center of a lot of things (incl. AtariST GEM desktop)

Those front panel switches were useful for single step debugging. When set to single step mode, the program would advance just one instruction at a time as you toggled a particular switch. At any point you could examine the contents of any memory location. You could see how branch instructions were operating, and see the program counter change as it reached an "if greater than", or "if less than" instruction. And the front panel looked really good too.

Years ago I worked for Hughes Electronics in SGS (satellite ground systems). Now obviously when you have a multi-million dollar satellite up in space you don’t upgrade the hardware or software controlling it and instead just run the system that was installed with it for the life of the bird, usually 10-15 years. As much as we tried to avoid it there were occasionally bugs in the software that needed to be verified and fixed. And in order to do that we had to have the same hardware as was installed at the ground station. In one building we had a gigantic server room, typically called the fishbowl because of all the glass (and the odd creatures contained within that, like fish, didn’t function well outside of that environment); the windows were decorated with appliqués that looked like fish and various aquarium bits as well as fish-related drawings done with whiteboard markers. Anyway, it was like a museum in there - we had representative minicomputers of every ground station that we installed that was still in service, with the old computers only being decommissioned when a satellite was taken out of service. When I last worked in that facility we had systems dating back to the late ‘70s, mostly PDP/11s - a veritable rainbow of systems that was quite a sight compared to the boring modern beige boxes that were standard at the time. One of the devices that I was responsible for was an optical media library that was part of a hierarchical storage system. Depending on the age of the file it would be offloaded from the internal hard drives to optical storage to tape. The server had six 4GB HDs for 20GB of RAID5 storage. The optical drive mechanism was huge, the size of a large refrigerator. It had six optical drives, with room for six more, about 120 cartridges and a robot arm to pull the media and install it into the drives. The drives were not double-sided but the discs were, so when the other side needed to be read the robot would go over to the drive, push the eject button, grab the disc, flip it over and gently reinsert it - it was quite a sight. The capacity of this massive, expensive, complex array? About 500GB, an amount that can now be stored on a solid-state memory card no bigger than your fingernail.

I had a friend in high school whose dad was a lifelong DEC employee. He helped the engineers at GM try to develop the Wankel rotary engine and then went on to help NASA engineers at the Michoud plant. Of course I had no idea at the time how cool the stuff he was working on was so I missed a big opportunity to learn from him. He loved the company though and was crushed when it closed.

I spent 3 years at college using the PDP 8/e series of boxes and have many happy memories of talking and working with the DEC engineers. The beliefs and standards at top level in the US came across the water and was instilled all the way through the teams - nothing was ever too much trouble for the engineers, software teams or even reception when the phone system got you lost. Amazing, even 40+ years later, I still remember them fondly. Two things you did not cover - some of the DEC drives where encased in concrete to reduce vibration - try carrying them upstairs and fitting them in the racks - took three of us (engineer, tutor and student - self) to lift them! The second is that the drives sometimes would not boot without a boot loader installed from paper tape. We needed to manually enter the initial loader using the switches to read the console tape that contained the 'high speed' optical tape driver, then read in the basic OS from optical tape that then allowed the disk to boot - time from start to finish was around 20 minutes...

I remember when I was in high school I was at U-Illinois in the 70's at the Digital Computer Lab (DCL) and saw the grad students writing code for a PDP-11/23. One of them said, "oh yes it's exhibiting the same problem" and so they pulled one of the circuit cards and ran upstairs to the electrical lab, changed a chip at a soldering station, ran back downstairs, and installed the (now fixed) circuit card ... "Ahhhh, that's much better!" It was not running UNIX but it was running one of the first Pascal Compilers ever.

Brilliant from start to finish. And yes, please lets see that Alpha video!

I worked in the early 80's on a Schlumberger well logging truck. It had 2 militarized PDP-11s with mag tape for bulk storage. A thermal teletype was used for the console - all keyboard activity was logged with timestamps and the scroll was preserved with the records for the job. We beat the daylights out of those computers in the field, but they did the job and just kept working. memories ...

I used to work for DEC. What a great company