From Core Memory to the Internet: Amazing History of the PDP-11
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- Опубликовано: 16 сен 2024
- Dave takes you on a journey from core memory to PDP-11 that hosts its own Internet homepage, along with a history of DEC itself. For my book on the spectrum, see: amzn.to/3XLJ8kY
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Thanks to Curious Marc and the Facebook PDP-11 group for the PDP-11 footage/images!
Thank you Dave, this story deserved to be told and you were the right man to tell it. I worked for DEC in the 80's and sold PDP-11's and VAXen to OEM's who built around them as the heart of end-user application systems. Four of the PDP-11's found their way to Beijing where they controlled the traffic light system for bicycles. We were told that DEC's PDP-11 business was so large that it would have been a Fortune 500 company in its own right!
My mom had a full career (or at least 2/3 of it) as a keypunch operator and verifier for the Navy. Thanks for the memories.
My mom started her career at General Motors doing the same! 👍👍
Dave acting like we wouldn't listen to him talk about this stuff for a full hour is crazy lol always love these videos and learn alot
What kind of a bear are you? What
As a total tech newbie in 1978-9 at the age of 28 I became part of an IT team at a local newspaper chain in the Chicago area. We had remote local offices we communicated with. All this was controlled by PDP11-70s and CDC drives that were a nightmare. As a true newbie I new this was unique stuff but I hardly knew I was in the midst of a computer revolution. So it was great to watch this video. We eventually progressed to a Tandem NonStop and I was involved in the IT dept of newspapers until I retired in 2016.
The 1st computer I ever used was the DEC PDP11/34 back in 76. Dang I hated those bubble cards!!! But it started my love for computing! I eventually ended up owning a national ISP, and writing the #2 Facebook app in 2013. Thanks DEC!
Definitely would love more videos like this..
1980. PDP 11/70 Accesed from a line terminal through a 300 baud modem about 20 miles away. Learned BASIC programming. First place I ever played Oregon Trail. It was fun modding that game. Also wrote a random word generator based on a statistical spelling model from a sample input text. It was useful for generating names for D&D. I still have the program printouts.
In 1973 the Univ. of New Orleans got a PDP-11/15 in Lab configuration - many analog to digital and digital to analog convertors, several binary connectors to detect triggers. I programmed it using a paper-tape O/S. The Univ. of New Orleans had a PDP-10 with a PDP-11 cross-assembler and paper tape punch. I used it for my dissertation research. It did data acquisition and immediate computation so that I could get results within seconds after the experiment finished. I could take data at rates up to 1 signal every 200 microseconds. Got my PhD in the field of analytical chemistry with a chemical kinetics project.
I later worked for a company that built oil-and-gas pipeline control systems in the Supervisory Control and Data Acquisition category - SCADA. We had maybe 40 to 50 such systems out in the world before VAX came along and provided much more robust environments - until PCs came along to take over that market.
2:23 I never knew that Elvis worked as a computer operator. Pretty cool.
The fingers, always look at the fingers 😂
@@derekbrotherton3462 ?? Why? The guy actually looks like Elvis. It has nothing to do with AI.
@@derekbrotherton3462it has been the real check, like the forever spinning top in inception. 😂
The computer I had on the first flight simulator I maintained was a 3C (Honeywell) DDP-124. That computer was a 1965 design if I remember correctly. It used magnetic core memory. We added a second simulator with the same computer. After moving it from North Carolina to Seattle, all we had to do was put the switch in run and press the start button. No reason to load the program into memory after the move since it was still there.
Several years later I finally got to work on the PDP-11.
At a telco, we came across a really old glass terminal that hadn't been run for years. We turned it on to be greeted by the last screen it showed before decommissioning, that old core memory is crazy stuff.
Core memory was really useful after a power outage.
My very first paid job in 1978 was developing factory automation software on a PDP-11/34 which was then transferred to the factory controller which was a PDP-11/40. They both ran RSX-11M but different versions; while it was easy to upgrade the development machine with a new version of the o/s as part of the learning process, it could not be tolerated on a live 24H system so it was stuck on V2.0.
We took DEC's DECNET networking software, where they conveniently supplied all the source code, and developed our own cut-down version of it (UBZNET) that was tuned to our needs to link the 11/40 with our 11/03 systems which ran the equally cut down RSX-11S. Happy days. I'm really enjoying your chat about all this, more please!
Did my BSc work on am 11/34 in Germany in 1978. We controlled 100 ton press tools. It was fun. I still have the paper tapes.
Hi Dave
First used 11/34 as a component of Xerox 9700 laser printer. We built our own analog digital controller Another project used a 11/70 (I think) behind a high speed serial 9600 haha silo. Then used a sbc 11/21 to sample incoming variable frequency telegraphy. Wasn’t quite fast enough to pull phase out so hot clocked it with a faster crystal about 4%. Worked fine!
Loved to see them in your garage. Best to you.
I sold my company that serviced Basic Fours in Southern California in 1980. The company I sold to, ICE, was a Dec dealer so they wanted me to go to an upcoming meeting. It was in Arizonia and DEC rented the entire resort, everything was free. Ken Olsens brother was the overseer of the meetings was unbelievable.
Thankyou. I programmed on the Arpanet, PDP8s, PDP11s, and VAXs. I served in Boston in its OEM Advisory Board, and encourage progress. DEC eventual became outdated because NETworking was limited. A DEC system with 30 terminals was considered huge, but compare that to networking where business and government commonly have networks supporting thousands of users today. To this day, I still program with a history in 16 languages. That being said, DEC was actually the real beginning of modern computers today. DEC however did not as was reported here use UNIX greatly, but instead had its own networking system called CTS-300.
Absolutely wonderful. Nostalgic, informative, entertaining.
Dave is a great presenter.
Thank you for sharing, I remember helping networking three PDP11 together with thick Ethernet. My overwhelming memory was helping install 5 smaller “boxes” on the same Ethernet segment and thinking they were really special, tiny quiet and with 8 vt200 terminals. I was amazed at the size of these other boxes compared the the 8 racks of the pdps. I was convinced I had seen the future of computers. It turned out these smaller boxes were just terminal servers interfacing serial to Ethernet then connecting to the pdp host. To be fair I was only 7 years old at the time. I learned much more over the last 45 years
16:09 out of time?! It’s Your channel, You decide how long to make a video. I’ll gladly watch Hours of fascinating content. Please consider making longer videos.
I remember networking a bunch of IBM clones that I had built for our research lab, initially using a couple of DECnet 1Mb/s coax cards with some 'open source' software to create a router to put us on the backbone of the Texas Medical Center (that is probably the Texas node on your map). The real network people were all running Sun workstations, that our lab could not afford. Getting a DOS 3.11 PC to run a stable TCP/IP network stack was a major pia. But what fun when it worked. We advanced through the Windows over DOS era and Win95. But my real aha was when MS realeased the beta of NT. I thought I was in high cotton. All in the late 80's to early 90's. I remember setting up NT on a DEC Alpha workstation in the later part of that time. It seemed like a mainframe to me, with 128M of RAM and a couple of fast SCSI drives. And now I have a phone in my pocket with more RAM and storage, and probably similar computational capability. What a trip the last 40 years has been.....
I see your name come up an awful lot too. I don't know you jiffy but I hope it's not Epstein. Probably is though
Don't know ya. And jiffy, I probably dont want to. Gargantuan
Thanks Dave, I trained and maintained the Perkin-Elmer 8/32D Mini-Computer while serving in the USAF from 1984 ~ 1988, these supported the C-130 Flight Simulator located at McChord AFB.
These machines all had Core Memory and storage was done via both 80MB and 300MB CDC disk pack drives.
I worked on the same trainer at Pope AFB from 1985 to 1995, as an airman and as a contractor. Bselch, pasla, master controller, sub controller, racko tacko. I can remember some of the terms. 😁
@@Jeff-vv4pn very good and thanks for your service as well ;)
I tried to get sent over-seas to no avail, I didn't realize all the non-US air bases had been contracted out already to support the sims, so instead of visiting new places I got sent about 150 miles north on I5 from PDX, my hometown.
Hi from London! Great video thank you! Started my IT career in 1984 as an operator using Systime computers which were PDP 11 computers (ours was an 11/70 clone - a Systime 6700 I think). It was a Unibus machine running RSTS/E with around 1.5MB of Ram. It would comfortably support 40 users/ processes. I have really fond memories of that time fresh out of school at 18. Our tasks were running jobs, printing, cleaning the tape drive heads. Not forgetting the all important disk copies at night (128MB removable packs) and having to take the disk packs over the road to another building for off site storage. I do remember we used to receive files remotely for processing so had some external connectivity. We also had to have the disk packs checked regularly which would involve a suitcase style machine to mount the pack in and the engineer would examine the individual platters using a wand type mirror and a magnifier device. Would really like to see more PDP content here. Cheers again!
You could store all those boards in a filing cabinet using folders preventing wear and tear on the boards.
Thanks for the memories. I programmed the PDP11 from 1973 for many years. I was always very impressed with its architecture.
Great video Dave! My first experience with DEC equipment was in second year university in 1979 where for a Fortran programming course we used VAX 11/780s. We studied the architecture of the VAX later in the degree and did some VAX assembler programming. It was a very elegant, logical architecture and the assembly language very clean and logical also. As a side point, I was interested to see that the PDP11/70 used AMD 2901s for the CPU. I used AMD2901 bit slice processors myself with a TRW hardware multiplier to make a digital signal processing system for my final year project for my degree. Great memories of those days!
I installed many a PDP 11/34a in auto assembly plants in the late '70's and early '80's. It was a marvel to bring up RSX-11M and M+ and our proprietary software, some third party comms hardware, and have it run the entire plant. I also installed 11/44's in other process control environments, and they were challenging to maintain. Working for the same company I became involved in DEC systems at various government agencies where I was exposed to 11/70's and more expansion chassis then you could shake a stick at! Some of the best and worst times of my life being in that 'gummint' environment. That box of loose DEC modules in your video without separators between them or a PCB stand would have given my old boss a heart attack! He had a six car garage full of PDP's and associated parts at one point. Alas, they are history, as is he.
I was a Senior Consulting Engineer at DEC. Ken was beloved by all ... Bob Palmer, his successor, not so much.
Great video Dave, thank you, fantastic to see some history on DEC and the PDP-11. I joined DEC in 96 worked in the PCBU in Sydney Australia as a server specialist on Intel servers. Best company and team I ever worked with. When Compaq took over I became an enterprise account manager and one the customers I looked after was the NSW government Roads & Traffic Authority. They still had PDP-11s operating in 1999 running the Sydney traffic light system called SCATS (no joke = Sydney Control Area Traffic System). For many years they had a custom support agreement with DEC to support these PDPs. The CIO gave me a tour of the computer room to show me. I had to give the notice that that they would longer be supported. They migrated to an NT based system. Thanks again!
Loved PDP-11s in the day. I mostly used Unix in the late 1970s and then moved on to developing RT-11 based systems for customers who either were colleges or businesses desiring to do accounting like computing phone charges which were imposed on us by the silly phone company tarrifs in the day.
I wonder how many of Dave's PDP-11s I actually used? Oregon State had one, but I don't recall which model (maybe a 11/40?). The US Forest Service in Corvallis had a PDP-11/34 running RSX-11M which I worked on for several years
The PDP 11/34 brings back great memories. It was a magical experience using one. And yes Dave - more videos about the PDP series would be much appreciated!
My first PDP-11 was an 11/60 running RSTS/E V6C back around 1977 or so at Northern Kentucky University. I was a COBOL/ASSEMBLY programmer on the IBM 370/115 running DOS/VSE and was the only one willing to become the new beastie's system manager. Went to 3 weeks of training at the Rolling Meadows facility outside of Chicago. That's when I fell in love with DEC stuff and became a DEC employee in November 1979.
From my early days with IBM 360 series to later Cray mainframes, the VAX series in the 80's was the one that brought the personal experience that laid the work for later PC's in our lives ... and later Linux with it's versatility for development. I used to say that I had code that was older than a lot of the engineers around me ... that only needed to be re-compiled for a new environment and were capable of still providing useful and needed results. Love watching all of your videos and reliving some of these memories ...
Awesome video Dave! Love the history, especially the homage to Dennis and Ken from Bell Labs. We owe those two a lot for sure.
I used a PDP-11/70 back in 1983 in college to attempt digital audio sampling of musical instruments for a group project. It was hilarious! We were able to sample low-frequencies (bass guitar) OK -- they only sounded slightly awful. But the high-frequencies (e.g. flute) were hideous. We consoled ourselves by playing a lot of Star Trek! A few years back, I was given the carcass of an old PDP-11/34 -- the one with the keypad and the selector switch instead of the toggle switches -- but they had removed the transformer and I was never able to get it repaired. Ended up giving the parts to a local PDP-11 User's Group. I hope they eventually got it fixed. I love to see the old hardware (and software) up and running. Thanks for bringing back some fond memories!! Now I'm heading over to the Attic...
One of the first computers I had direct access to was a PDP 11/34 running RSX-11 V3.2, (which we later updated to V4.0), RK06 disks with a VT52 terminal. Learned assembly language, FORTRAN. That machine essentially bootstrapped my career of now over 40 years. Thank you DEC!
This is fascinating stuff, I can’t get enough! Thanks for sharing all this! ❤
My University in New Jersey had VAX running VMS operating system. We used software called LaTex to print our research papers! It had serial interface used for connecting video terminals. Today they are called flat screen monitors. Thanks for giving commentary on amazing times we have lived through. It would be interesting to offer "History of Computers" subject in the universities. But new generation may not be interested in the old days (about 25 to 30 years ago) of computers.
Many years ago, when I was taking FORTRAN at night school, I did my homework on a VAX 11/780 running VAX/VMS.
Great overview/potted history of DEC. Olsen was undeniably a visionary & his products lowered the bar & popularised the widespread use of computing without the need for the high priests of Data Processing
Excellent presentation. Thank you. Really enjoying these.
Many thanks for another excellent DEC enabled time travel edition Dave. Wonderfully entertaining tech story telling with lots of memory triggers for old DEC hands. Slainte!
In the early 1970s I worked for a manufacturer of semiconductor products in a group that made equipment to automate the testing and manufacture of their product line. We decided to use a PDP-11/20. One of the team members wrote a PDP-11 cross assembler for a CDC 1700. We submitted hand written code and the next day would receive a printed listing and executable code on punched paper tape from the CDC 1700. The PDP-11s we used didn't have an OS and we had to enter a bootstrap loader via the switches on the front panel to read the punched paper tape.
As usual amazing job thank you
This bring me back a lot of memories !!! I started my IT career in 1982 in a company and was Cobol programmer on PDP 11/34 and 11/70 . Was such a great experience and I remember when we were doing joke like type run $mcr on the console to crash the PDP we used for development 🤣 🤣🤣
I worked for Collins Radio beginning in 1977. It was taken over by Rockwell Switching Systems shortly thereafter. Collins built one of the first Automatic Call Distributors (ACD) which was powered by the PDP 11/35. The terms you used, like Unibus, gave me a huge dose of deja vu. Thanks for this. Wishing you all the best.
I used to work on some Collins 8500 computers in the Air Canada reservation system. It was the communications front end for a UNIVAC system and included several PDP-11s, each connected to several modems connected to the world!
I worked for DEC briefly in the 1980s and later on another well known American computer company. Behind the glass of the computer room was one of that company's own minicomputers which had been chosen as it was physically larger than the VAX-11/780 hidden behind it which was, unlike the machine in front, actively being used.. kept the management happy.
Dave's Garage, awesome video it was really good
I first used a VAX when I would visit my mom's office at the US Treasure Dept in 1983. I would hack on that thing all day long and would initiate chats with her colleagues in other offices using the 'talk' app. Good times!
I was a math/physics major from 1974-1978. In 1976, the science department got a PDP 11/34 running the RSTS-E (resource sharing/time sharing-enhanced) operating system. Every science student got their own account on the system. My introduction to computer programming was a semester of DEC BASIC, taught from the DEC BASIC user manual. We had far fewer terminals than students, and if we couldn't get on one of the two VT-55 terminals, we had to settle for one of the eight ACT-1 terminals, or one of the four DECwriters. Those were 300 baud teletypes, that used a keyboard and printer. They were a pain to program on. In 1977 and 78 I learned to program in FORTRAN on that same system. I was among the computer geeks that hung around the machine after class, and became admins. Fun times.
I really enjoyed the video. This era was before my time, but it offers many lessons to learn for me.
Great vid Dave - there is a 11/23 still running the master equatorial servos at the Parkes radio telescope. The days of the PDP development were amazing. Have you read "Soul of a New Machine" by Tracey Kidder? A Pulitzer prize winning book about bringing a PDP level ( however 32 bit vs 18 for the PDP) machine up from chips, blood, sweat and pizza 😊. Data General but DeCastro started out at DEC so much of the spirit of the PDP infused DG and its products.
I have never been near a PDP, but since they were the birthplace of C and UNIX they will forever be interesting to me.
Always a top-notch production Dave!
I worked at DEC and moved to Maynard so I could walk to work and practically live at the office. My department did double duty, we wrote the tech manuals and taught the first field engineers. I loved those days. The bosses nickname was Uncle Ken.
Dave's video is an awesome walk down memory lane. As a teenager, I built a school administration application that ran on RSTS/E. I created a company that sold it to over 300 school systems in the US. I installed it on countless PDP-11 variants. Back then, I wasn't a fan of the 11/34 due to its slow speeds compared to other PDPs. The 11/44 was my favorite. We even bought a new one for $100K. Huge money in the early 80's.
Sounds as if the PDP-11 was the Raspi of the 70ies :)
My beginnings were on a pdp11/40 that had 112KiW core memory, a few dz and du serial multiplexers, rp11c disk controller, two line printer controllers, high-speed card reader controller, mt11 9-track tape controller, dual DECtape, dual 8" floppys, and possibly some things I forgot about.
I learned a lot from the pdp11 starting in 1977, mastering it's assembly language and becoming proficient at compiler code generation and operating system related techniques (the school used RSTS/E on this machine).
The instruction set architecture is amazingly clean and orthogonal. Some of the extended instructions violate that, and the "mark" instruction is an abomination that I've never seen used in legitimate code.
I worked at dec in Maynard for the first half of the 1980s, did graphical firmware and some drivers for the professional 300 personal workstations, and ended up designing serial terminals.
The pdp11/40 was in the BBN imps that were the thing used by everyone to connect to the ARPAnet for a long time.
The Parkes Radio Telescope is still using a DEC PDP11 to control the positioning of the dish, or was as of about a year ago (im sure they still are). Im sure there are still other PDP11's in use out there because of their reliability an ease of use. Great machines!
Cool stuff. Yes, more videos please.
Takes me back to the old days - The Chem E department had a NOVA computer used in the process control lab. It was a big day when we got a whole 8K of core memory and 2 MB hard drive. Grad students got to do the upgrades. When I entered the work force there were PDP 8’s everywhere running gas chromatographs in refining and chemical units. That was back in the day of hands on the iron.
In the early 80s while I was in the Air Force, I worked at Strategic Air Commad Headquarters in Data Automation. One of the computer systems I wrked with was an Intelligence Communicatons Computer that was a node that communicated witn other intelligence organizations such as DIA and CIA. It used PDP 11/70s. As I recall, it used five PDP 11/70s.
PDP 11-34 guy here. I got a job at a check printing plant as the computer fixer. It had many VT 52 dumb terminals on a 20ma loop connection. the girls would type the checks, then printed on line printer, then proof read, then corrected as required and sent to 6 level paper tape punch. The paper tape went to lin casting machines (think lead) . The lead type was proofed and sent the check presses. I kept PDO 11,s running (2) and VT52,s and paper tape punches all running. PDP 11s replaced by IBM. It was a long time a go.
Awesome video. If the PDP-1 was the birth of the mini computer the TX-0 was the night of passion 9 months before :)
The picture of a pile of hardware in the back of a car is TRUE ! Ford started prototyping "electronic engine controls" (pre-cursor to electronic fuel injection) on a PDP-11 in the trunk of a Lincoln, in the mid-1970s. Programs were loaded via paper tape that was hand pulled through a reader !
Just loved the clip of the old key punch machine!
The picture at the 1:06 mark is the PDP-11/35 at New Mexico Military Institute circa 1976.
Dave I knew there was a reason I dig your style. S54 vert-silver. I’m not going to tempt fate with the transmission…
It's a shame to think of all the PDP and other computer stuff that has ended up in landfills when it could have found its way into the hands of those like you who appreciate and seem to truly love these pieces and examples of computer history. Great channel Dave looking forward to more.
The Basic Four, which used a Microdata computer, had 4 K memory which was two board hooked together with a flat cable.
I worked on IBM 88 collators which used relays for memory, they later pulled out all of the relays and put in a little box with core memory. Was really weird.
In September of 1988 when I started my Computer Engineering degree at Georgia Tech, they were still using an old PDP 11/34 to teach Unix and C to freshmen. We had, if I recall correctly, 16 VT-100 terminals in the classroom, all connected to the PDP 11/34 located in the next room.
By the time I started college the beginning CprE course on architecture was using the desktop LSI-11's -- still by far my fondest memory of any course. A PDP-11/70 served the whole class as we developed software and then downloaded it to our own LSI-11 to run. Final project was essentially redeveloping "pong"
Very interesting. Thank you!
Fascinating slice of history Dave, it straddled an interesting time from when CPUs were made from discreet logic and core memory to VLSI and semiconductor based ram, wow. Never seen one in the flesh unfortunately.
Wen I was the Army (1974-1977) they train in in computer repair. An NCR 500 built in 1955, IBM Keypunch & IBM Sorter machines🥸
I cut my IT teeth in 1980 on a Dec-PDP-11/70 at the Cambridge College of Arts and Technology (As it was before it was absorbed into Cambridge university)
It was this that got me an upgraded job at the company I was working for, as they were trying to computerize their manufacturing systems on A Dec-PDP-11. Later upgraded to A VAX.
Thanks for this video! Our department had a PDP-11 in the 1980’s. I’m kicking myself for not learning how to use it. I wish we found some place to store it, instead of disposing of it 25 years ago.
Dave just love the channel!
Thanks for the rundown of this historical machine. Looking forward to further installments of the life and times of the PDP-11/34. Love that big round screen that was shown!
The smirky laugh after saying "where I can compile a linux kernel in under 19 seconds" is gold. Yeah yeah Dave, we don't all have a 7995 ;)
Yeah, $10,000 CPU. Ow. My i9-13900HX laptop which I paid $1700 for takes 1m12s to cross-compile a defconfig RISC-V kernel. The alternative AMD 7945hx is basically the same too. Good enough for me! p.s. my first formal programming lessons were in 1981 on an 11/34 with 256k RAM, 22 VT100 terminals, and two LA120 printers, running NBS Pascal in the first part of the year, OMSI Pascal (slower but more complete and less buggy) later on. I'd already done a fair bit of programming (machine code in hex!) self-taught on an Apple ][, and on TI & HP calculators before that.
Dave - I always love your content and I've been in awe of you and your skills since my days at MS. I'd enjoy more on the "PDP11" series ;)
More PDP experiences, Dave!!
i love learning about the history about the old machines that were used back then when i wasn't conceived but still awesome regardless
Fun fact, for most of its modern life the train network in Melbourne, Australia was running on 4 PDP-11's (11/34's I believe) I'm not sure of their current status but they were certainly still operating in the 2010's :)
I remember installing a new server at a customer. The new machine was basically a big workstation running Unix and having software such as Word Perfect installed. The users accessed it though serial terminals and they would handle all the compute requirements for ten users and handle every thing the company needed. It went just next to the DEC rack that they had used so far and was a lot faster and had a lot more memory than their old DEC with it's core memory. Their IT guy was just laughing when he saw the new machine, and it did look ridiculous beside an entire rack like that.
Core memory was interesting in that it was actually serviceable. A broken memory usually had a wire that was broken or component failure had burned the wires. Yet you could thread new wire through it to replace a damaged one. But the cores were really small you you would use small crochet hooks to handle the wire. But these memories were not compact. 65 kb of core memory is a lot! That includes 65536 cores. You do not want to try to crochet one of these just for fun...
Wrote my first code in 1975 at high school computer club - just as you explained. Write code on a gridded paper sheet, send it to local university. A week later get result back, which was usually something like "Syntax Error Line 2". Didn't put me off computing though!
In my grade 12 FORTRAN class (1970-71) we used pencil mark cards!
Anyone here remember coding sheets? Radio Shack and others sold them for BASIC.
While in the USAF I operated an IBM 407, Burroughs B3500, B4700, IBM 360, IBM 370, PDP-11 and I was there when they were replaced!
One of my prized possessions from my first IT job as a programmer/operator for an IBM 1401 is the core-storage unit from a 1403 line printer that I took from a junk pile when no one was looking. It still looks amazing after all these years.
To be honest as someone who didnt grow up with these they relly dont resonate with me, but as someone learing to program microcontrollers i find it super interesting how these older computers worked. Id love a technical deep dive into the design of it, the hardware and ciruits that maek it up and why , and how its evolved over time. Looking forward to more whatever it is about. I also like the prime sieve thing you did and sort of wish you gave us some lessons how to write one, maybe even in assembly. How would programming for risc architure differ with assembly? I heard risc has better throughput, esp32 c3 and c6 run on risc processors, would be cool to test the difference between prime sieve on risc vs non risc. But whatever you choose im hear to learn, laugh, and cringe. Heres an idea for an series, "lets write an OS" content for days...
You mean "RISC-V" for ESP32 C3 and C6. The older ESP32 are also RISC, but a variant called XTensa that is proprietary to chip design tools company Tensilica, who possibly weren't too happy with Espressif exposing their CPU cores and ISA to end users.
02:47 "Give a stack of cards and get result returned. If you were lucky it worked."
You also got a "core dump" - which is a print out of all the memory registers with the variables. In this way you could find out were the program went wrong.
Great story well told Dave, really interesting as always. I remember having a go on the PDP-1 at the Computer History Museum in Mountain View when i was on a work visit to the US. Played Space War !
I think these machines are very interesting. I have some experience as a user of an IBM 1130 in the late 1970s, I guess it is a bit smaller than a PDP. I would also be interested in how and why the VAX was developed after the PDP. I've heard that the VAX was even hardened and repackaged for use in aircraft. I've also read the Tracy Kidder book about the Data General competitor to the VAX.
Was at DEC Sales Support starting in 1987 (MDO RCH if any Deccies out there) and I recall the VAX 11/780 was named that because, even though it was a completely different machine architecture, DEC wanted customers to feel comfortable that the VAX was an extension up of the successful PDP-11 flagship. I recall, when the VAX was announced, everyone was asking us, "Will it run RSTS/E?" Good times. Ken came and spoke to my newhire class in Shrewsbury MA, told us, "This PC thing is a fad. Customers want mini-computers!" Well, that was Ken.
VAX was developed to move DEC from the 16 bit to. 32 bit world. Although processors like the 11/44 had an external address bus up to 22 bits wide and so could address 4 Mbytes of physical RAM an individual program could only reach 64 kbytes of that. It also only supported real memory and not virtual memory - and real memory was still pretty expensive at the time. So DEC created Virtual Architecture eXtension which was a true superset of the PDP11 instruction set and could run PDP11 programs in compatibility mode.
@@Richardincancale Yes I believe you are correct and better said it than I
Thanks for the video. I remember fondly being the system operator of a PDP-11/34 lab at the University of Missouri Columbia in the early '80s. Fun times.
In 1980 I worked for a company called Tektronix. They resold DEC PDP11's in self contained racks. My job included three things 1) Pulling off the DEC Nameplates and replacing them Tektronix nameplates & stickers. 2) firing them up into a preprogramed diagnostic sequence. 3) Ensuring the Peripherals were all installed and operational. I still have one of the circ fans that would have been installed in very top of the rack (6' tall?). The fan was massive and the throughput was outstanding (still kicks butt 40 years later). Last in your video a disc was seen being installed about 15" in diameter. Open up the r/w door and you could see a laminated oxidized (rust orange) humongous disk. I kept one of those as well but tossed it about 15 years ago. What a huge mistake that was. So the question is do you know what disk I am talking about and it's spec's? Love the videos by the way!!!
The BMW that you have on the back its beautiful. e46 M3
I never was much into the hardware, but when we were looking at doubling our Dec 11/70 memory, I could not believe the price given at a large computer conference for a 3'rd party upgrade. If I remember, about 4 times the memory upgrade, for about 1/2 the price. Dec did the upgrade for us, and I never heard any complaints from them. We must have had core memory in the original machine in about 1977.
In 1978 I used the LSI-11, the PDP-11/34 and a PDP-11/70 at a huge food factory.
The 11/70 controlled controlled or monitored many machines in the factory via a DIY LAN.
The LSI-11s ran as real-tme controllers running 'Smith Predictors'.
I have a 1969 "digital computer lab" from digital equipment corporation. It's got a wooden frame! Comes with a workbook with different labs to program it for and teaches in detail about the specifics of financially efficient logic operations. It's pretty sweet works great still!
Great video! Thanks.
My first boss in 1986 had a chuck of core memory in a Perspex sandwich on his desk from a project he'd worked on - the auto land system from the HS Trident airliner
Ah... the days as a freshman at university, when I got my hands on a PDP-11/44! And what did we do with it? Many things... including playing a port of ZORK! LOL Oh, the COBOL, REAL BASIC, Pascal, etc., etc., even DECTalk! LOL
We had a PDP11-34 in the lab at New Mexico Tech in the late 70's, used mostly for student projects, especially those in the graphics and animation area. We also had a DecSystem-20 for general student use as well as all the administrative computing. I believe the Dec-20 had a built-in PDP-11 front end to manage the interactive terminals on the system.
@DavesGarage6 How do we connect?
Late 70s the first PDP-11 I saw was the 11/03 at the local junior college, it was small enough they had 4 and a single 11/40 for the Computer Technology program. The university I attended had the 11/70, 1st floor of the School of Science, behind a glass wall of an environmentally controlled chamber attended by a priesthood. Just like we'd read in the histories.
The trip I made to VCF PNW (2019) there was one fellow there with a DEC setup on display, he had worked for the SEC, he said the private network that connected the exchanges in NY, Philadelphia and San Francisco was done with 11/23s at each node. Fascinating.
Been a while since I saw the digital logo.
Not old enough to have seen it on much else but network cards, but still, a memory.