I'm retired Navy and in the late 80's and through the 90's we had a full PDP-1170 that did classified message processing. It ran RSX-11 and it was so fun to work with. I got to the point I could tell what the system was doing by just watching the blinkin' lights. Thanks for the trip down memory lane. Computers were so much fun to work with back in those days.

@classicnosh

2 ай бұрын

I could tell by your SN! Thanks for your service.

@aytviewer2421

2 ай бұрын

In the 1980s, we had Honeywell DPS-6 mainframes on the carriers. I think I could still boot one today! Not to mention mount 1600/6250 bpi tapes and run a decollator to separate the 4 layer carbon copy printouts. Ah the good old days!

@BlankBrain

2 ай бұрын

I ran Prime 400s, and I could definitely tell what was going on from the front panel. Sometimes I'd set the display address to the user number so I could see who was hogging the system. Later systems had a Z80 VCP (virtual control panel). It was much less helpful. You typed octal rather than using binary switches.

Thanks for this video Dave. In the early 80's I worked in DEC Field Service and repaired a lot of PDP-11, 34, 40, 45, 50, and PDP-11/70s. Shortly after that I moved to the software group installing RSX-11M for all the local clients. After that moved on to VAXen and VMS. What a great time of life.

@pietergeerkens6324

2 ай бұрын

Ah yes - those were the lazy hazy days of summertime: hand toggling in, from the console, 12 feet of paper tape bootstrap because the System engineer was enjoying the department's annual day at the golf course and had hidden any extant spare far better than I could track down. Once done, and verified, I made 3 copies: - One for the computer room; - A second for the errant systems engineer, left unsigned on his desk; and - A third for the back of my desk drawer - because I had no intention of repeating THAT hot summer afternoon.

@c1ph3rpunk

2 ай бұрын

The loss of DEC still hits me in the feels. People that didn’t have the fortune to experience it just can’t understand the quality of those systems. I’ll add, the field service was, hands down, the best I’ve seen and still compare vendors to as the high bar. All of you in the field did truly excellent work, thanks for all the help over those years.

@robertlange9107

2 ай бұрын

I, too, worked for Dec. I learned so much and was encouraged to do so. I had an 11/23, 11/73, and 11/83. Had A-D/D-A board in them and programmed in Macro-11 on RT-11. Did some work with RSX-11M as well. I remember toggling code into the PDP-11/40 as well numerous times. Bootstrap code 173000 for the diagnostics operating system. Can't remember what it was called. Many good moons ago. What fun...

@KlodFather

2 ай бұрын

My friend John was DEC support in our region and has a complete PDP11 set up in his basement fully featured with all options and accessories. Terminals Teletypes Tape Drives etc... That thing should be in a museum or with someone who will use it and love it. Its operational.

@SyberPrepper

2 ай бұрын

@@KlodFather If I had room, I would love to have a setup like that. There's probably a museum that would love to have it.

This video was so much fun. I first learned to program in high school on a PDP-11 in 1973. It was an interesting experience because to boot the system, we first had to set the address and the instruction using those switches on the front and then loading them before advancing the address and repeating this. This was simply to program a boot loader that would read the punch tape attached to it. Once that was in, we'd load the punch tape and execute the program to read the tape. This would load the multi-user OS and Basic in about 15 minutes. We'd then venture to a Teletype terminal that had its own punch tape reader and load our previous day's program into memory so we could work on it. Each user only had about 1K of addressable user space in memory, so we got very crafty on writing concise programs, reclaiming/reusing variables, etc.

@markanderson8066

2 ай бұрын

I was on an PDP11/8e at my high school at that time. Fun!

Back in the 70’s I was a grad student at UC Berkeley when the first UNIX tape to leave the Bell System arrived. The box had my name on it! Shortly afterward, Ken Thompson arrived for a year long guest professor appointment. We spent many evenings with the PDP-11/40 while I worked on my project and he debugged a persistent but intermittent crashing problem. Fun times! He fixed it by adding 3 feet to the Unibus cable to the swap disk to fix a hardware timing problem. Soured me (an EE major) on the PDP-11 architecture forever! I went on to work on Data General machines and build Electron Beam mask makers. Now I play with Raspberry Pi Pico’s and design a few PC boards for fun! Thanks Dave for sharing all the crazy stuff you do.

What a great trip down memory lane! I was a CS student from the late 1970s through the early 1980s. Our department computer was a PDP11/70. My advisor was very proud that he got a 256K memory upgrade from DEC for just the annual maintenance cost (of $10K). When I started work in 83, my first job was writing software for a PDP11/73 that was the workstation part of an in-circuit processor emulator product line. So, I remember the PDP and Unix quite fondly. Thanks for the great video.

I worked for DEC in the late 1970's. The computer lab in the part of the company where I worked had a bunch of different PDP-11's. Each of the systems was named for a character from "the Lord of the Rings", except for one. That machine was a hugely expanded PDP-11/70 named "The Ark" (it had TWO of everything interfaced to it!) The second largest system was named Gandalf, there was a small 11/20 called Bilbo.

Impressive. I worked for DEC for 17 years, starting in 1977. I must have installed at least 100+ RSX systems. Wrote dozens of device drivers and worked on many application projects, many in assembler. The nice thing about RSX was sysgen, you answered a bunch of questions in the morning, and then went to lunch while the exec assembled, so you were guaranteed a lunch break!

@jylfarm1964

2 ай бұрын

I did install a thousand of RSTS/E... 14 hours a pop

@vcv6560

2 ай бұрын

Oh that's painful, but flavorful 😁

@SyberPrepper

2 ай бұрын

Loved RSX-11M and Sysgen was great!

@Reverend11dMEOW

2 ай бұрын

Two years of the Death Knell of the far Superior Alpha 64-bit CPU, at DECwest, then one of the Mgr, Dev, Test team left behind for the one year promised, with one Turbolaser (AlphaServer 8200 & 8400, feeling super-goofy watching a desktop OS pretend to be Enterprise, w/ billg's satellite Image system, with in-house 24/7 for the 32-56 Bluescreen Windows 2000 Server beta presented, anyways, my baby while it was still DEC. I can see Carly Fiona under Intel CEO's Gold-Plated desk doing whatfor and I do not want to know under his desk. Conspiring, planning how to dissolve Apha. Well, that was a $75k/yr wage, so I may be one of the three folks ever to bankroll $37.5k/hour that year. Good to meetcah. AMD Did rescue her FPU, I am told, so that was good. ITANIC we 'nymed it, our team beat Itanium to the desktop during Win2k Server Beta by at least three, maybe four weeks. Doncha just love it when these sleaze-ball Greed-Driven Money-Grubbers (the talk my mom sat me down to while the other kids are sayin', "Why don't they just git nekkid and show us instead of them turning all beat-red in the face trying to make us feel relaxed, which seems counter-intuititive, in'it?" take care ;-) Crime, the lot of it, everyone would get fed, PRIDE IN WORKMYNSHIP would not be so far distant in the past, removing Money completely from this sham we got stuck up our mutual derriere by power elite, powers-that-be and GAUWGHD only knows what is coming when Money will have to be fire-proofed when the frozen Methane starts bubbling up from the seas' floor. these people do not understand the first principle of Double-Entry Book-keeping, you see it on your BoAholes Transaction Logs, Debit Re-Ordering, which though they ceased and desisted with the Overdraft Charge it really irks me no end to find myself with an overdraft or three just by them moving the order of events out from chronological order. harrumph go figger That 3-5 days, we must check for oh you know Fraud, right that's it Fraud I say, while there imaginary profit engine is soaking-up the interest on said Refund sitting in an interesting-bearing account, while those of us with any sense left, the three or four of us left... [End_Of_RANT] i crack myself up seeing photographs of starved bloated-belly dead child floating down the river. I say, never mind, I say nothing. Gold-Plated toilets for all the self-avowqed pussy-grabbers. I do say that. And that is who everyone should vote for, seeing as how the Constitution self-immolated January 6, 2021. My mom did not foresee just how moronic the man upstairs looks when said toilet comes unbolted, flying through air like that one in the nukular test PSAs from way back when. And, please, do not get me started how they moved burns caused by scalding fluid from 2nd-degree to 3rd which is charred flesh, over $3-million phony baloney us dollah worth about as much as Zimbabwean TP. Duck & Cover yeeeeeee haw

What a trip down memory lane, Dave. I went to Northern College of Applied Arts and Technology in good old Kirkland Lake, Ontarion, Canada. Same old PDP 11-70 except the IOS was RSTS/E if memory serves me. The is where I learned to program using Basic, Basic Plus2, COBOL, Fortran, APG, and assembler. I did a research paper interfacing a Motorola D2 kit’s 8 character display and numerical keypad to a door lock solenoid and used the PDP to validate the credentials. Needed to code in assembler and download to the D2 kit. I remember stepping through memory banks in hex to fix issues because it was too cumbersome to code in assembler on the PDP, then convert to hex, download to D2 and then try it. But seeing a solenoid click after entering a passcode was simply magic. I still marvel at what actually happened to make all that work. Thanks for posting I thought I would never see at this time!

@OneWildTurkey

Ай бұрын

I used to love to hate RSTS/E. I was a student lab tech and spent most of my time rebooting it. Somebody was always trying to do something they weren't supposed to. Really Slow Time Sharing - it was a great intro to my next DEC experience, a lab full of Vaxes.

like so many other commenters, this was a trip down memory lane. we had a pdp11 in my High school's computer lab. we only had the base unit, no mag tape, no ptp, no card reader. all those were on the IBM1130. thanks Dave.

In the 1980s, I met a fellow at Comdex who had a warehouse full of PDP-11 hardware. After sufficient recreation, I agreed to buy one. Several months later, he showed up at my company on 24th Street in San Francisco with a truck full of stuff. After some hard work, we had several six-foot tall 19" racks in the main room of my one-bedroom apartment on the second floor. By the time we got the machine running, he had emptied my bank account with unexpected expenses, including sending several boards off for repair. Ultimately it was all working though. I had forgotten a lot about this kind of equipment, though. It not only dimmed the neighborhood lights when I turned it on, but it was really loud. When I ran it I had to keep the sliding door to the porch open so the heat could escape. I gave terminals to several of my neighbors and ran serial cables out the porch door to their porches and, ultimately, to their terminals. I got my hands on a tape of the Decus C compiler, and I was good to go. So, Dave, I understand your desire to own one of these beasts. It is a shock when you realize that the hard disk, which may have even been 10 megabytes, was the size of a washing machine. In the end, none of the neighbors felt like using a line editor for word processing. It was just a little too retro. It gave them a taste of what it was like to have computing at home. That was Goodall Computer Systems on 24th Street. Those were some fun days.

@b43xoit

2 ай бұрын

`ed` and `troff` forever.

Does bring back memories. I wrote quite a bit of machine code on a PDP 8 and then moved to a PDP 11. Digital really nailed the instruction set on the 11 with the mov instruction, device addressing via memory locations and great interrupt system - so clean compared to the PDP 8. The machine I worked on had core memory, I think initially 4kb then we upgraded to 8k with semiconductor memory? It ran with a cassette disk drive with maybe a megabyte of capacity, huge! It could run Unix. Not sure what model it was, but it had paddle keys, with the magenta/red colouring. I had to toggle in a binary loader to get it running. Used it to run a radio telescope and sample and process the output. Amazing what you could do in 8k of memory.

@markl3893

2 ай бұрын

Yes. I started on a PDP-5 that the university had set up in an engineering building room for students only. We had our own software budget and some other old electronics that got assembled into a working analog computer interfaced to the PDP-5, and now I'm seeing analog computers getting a fresh look for some problems.

I worked for DEC in Maynard for 18 years. My first home computer, in the late 70's, was a PDP-11 named a PDT-150. (PDT = Programmable Data Terminal. Ken Olson didn't care for home 'computers') Two 8 inch floppys and a PDP-11 in a box about 2 ft square. I ran RT-11 and a VT-52. I can still recall the clanking of the big floppies as it booted. Sadly, no row of blinking lights...

The CPU interface on the front of the case is one of those interfaces I love to see. So many switches! You can TOUCH the bits! I love that.

@consultingengineer5593

2 ай бұрын

I love your phrase: "touch the bits"

@brianvogt8125

2 ай бұрын

@@consultingengineer5593 I think I can go one better. At university in 1973, the Computing 1H tutor passed a core memory board around the class. I actually touched a memory core with wires criss-crossing. The university had a CDC 6400 and some PDP-8s, so I guess the board must have been faulty from one from those.

My first system was a PDP-11/45 at collage running RSTS . They taught B.A.S.I.C , COBOL and Fortran. Was very lucky to Have Dr. James drive by and pick me up and let me do my Fortran weather simulations over winter break. Had so much FUN having the system to myself. Disk pack was the size of a washing machine. Core memory was swapped out for semiconductor a year later. The PDP replaced IBM 1620.

My first email address was hosted on a PDP-11 in 1975 at UC Irvine. But I learned Dartmouth Basic on a PDP-8 with a teletype terminal and paper tape interface in 1973 (thanks Huntington Beach Unified School District), one of two girls in the class. I used to play Zork!, but my first video game was Star Trek on that teletype. I wanted to be a programmer, but my delicate sex and perceived poor math skills meant my school counselor steered me far away. But anyway, PDPs have always been very nostalgic for me.

This brings back lots of memories of using PDP-8, 1134, 1144, and later a VAX. I used to trade writing administrative maintenance programs in Fortran 4 for additional lab access, which i used the card reader/punch to avoid having to reserve kepunch time fot a 370 which I hated. (both the 370 and the keypunch)

I have not seen a PDP-11 in decades, takes me back !!

Thanks Dave. My first job after graduation was, in part, doing system admin for a broadcast television Teletext system,. It ran on 2x PDP-11/34s with RL02 (10MB) removable disk pack drives and the programmers front panel (octal keypad and displays - not as cool at the 11/70s paddles), one machine was equipped with 64kWord of RAM and the other had a massive 128kWord of RAM. The OS was RSX11-M-Plus. This system needed to do a lot of real time work in order to generate the teletext output steam to be synchronous with the television signal with microsecond accuracy. I've always marveled at how such a limited resource platform could keep up - truly a tribute to the efficiency of RSX11-M. Thanks Dave Cutler!

@cromulence

2 ай бұрын

This is fascinating. Who was the teletext service for?

9:33 "I actually had trouble connecting my terminal program to the five serial ports at first, but at some point it just worked" Sure, that how it often goes with RS-232!

Hi Dave, Found out I was on the Spectrum only four months ago, I'm 57 now so it takes a bit of getting used to. I used to hang around with my dad at the university computing centre and the research labs in the 1970s. I am sure I came across PDP/11s but only remember them much later when I went to university. I do remember playing the Star Trek game on the university UNIVAC mainframe in the terminal room while dad did his real stuff. I also played on a NOVA mini. Love your videos, just happened to catch this one just after you released it so I thought I would post to see if you were still watching. Cheers Andrew From Australia

Thanks for the walk down memory lane. I installed PDP-11s in robotic systems in the late 80s, early 90s. When 286, and especially 386, PCs came out the PDPs fell to the wayside. And yeah, I never played Zork on a customer's system. 😉

"Imaging how much smarter you'll be in ten minutes" - I spit out my tea! 🤣🤣🤣🤣

and people nowadays think they know how to work computers. great video Dave.

My favorite Assembly Instruction Set, ever

@davethetaswegian

2 ай бұрын

Ditto

@CFSworks

2 ай бұрын

I just realized I didn't know anything about its assembly language so I looked up some snippets. Feels very similar to MSP430 to me -- and I like the 430 instruction set!

@RalphHightower

2 ай бұрын

Yes indeed!

@SSJIndy

2 ай бұрын

Yep. I still have my fold-up PDP-11 programming card, EDT reference card and VT102 programming card.

@BoredInNW6

2 ай бұрын

The PDP-11 was a joy to program in assembler, at least compared to some other machines of the era. And when I met the 68000, one of the best microprocessors of the time, I couldn't help noticing that it was influenced by the PDP-11.

Dude, I could listen to you info-dump all day. I really appreciate you taking the time to share your knowledge. You love this stuff and it really shows. Kudos!

Around the time I was 14-15 years old, the Pinellas County Science Center had a Honeywell 1648A 3 computer (job, control, communication) timesharing system. We wrote code in Fortran and BASIC using an assortment of green-screen terminals and printer/teletypes. Those were the days.

Back in the early '90s, I was given a storage cube filled with, what I was told, three complete PDP 11/70 systems. The "only" thing missing was the OS. So I scrapped the systems, tearing them down and selling what I could (the bare racks sold amazingly well at hamfests), and recycling what the local recycler would take. I ended up with 3 of the control panels, a working DECwriter III, a rack with the PDP 11/70 faceplate on the top and both sides and front and back doors, and several of the power distribution systems. Most of those were designed for 3 phase AC, but were easily rewired to work on 110. Well, I went off to college, and I went to she shed the following spring. ALL of it was GONE. Yep, my dad trashed it. And those 11/70 control panels were MINT.

Brings back old memories. Used to work on PDP-11 product line at DEC in Maynard MA. Then went on to teach 11's. Also was tech on PDP-8's and PDP-10's. DEC was a great place to work, bar none.

Legend has it, that by placing your ear on the front of the PDP11, you hear STAYING ALIVE from Brother Gibbs! Thansk Dave! This machine is beautiful!

@nufosmatic

2 ай бұрын

The Brothers Gibb...

Hell yah, PDP11 video. You are my computing hero Daves Garage.

I used to have a PDP11 programming card that I had since the late 70's, early 80. No idea where it went when i moved in 2017. Ya. I'm old 🙂 I still remember toggling in the register entries to boot strap the thing.

@wlc7176

2 ай бұрын

I still remember how to boot TSS 8.24 and OS8 on a PDP 8/e back in 1975-1981.

PDP-11 architecture was very popular in Soviet Union. Plenty of soviet systems were compatible with it. They even made home computer on that architecture. I got a video about it.

@michaeleitel7186

2 ай бұрын

Yes. It was sold by DEC directly to Electronmasch (Kiev). As a west German young engineer I did there a 2x3 weeks training in 82. We had to use 18 of the PDP11 derivate called CM4 to control a steel plant in Kursk. Because of cold war restrictions we (on restricted time base) got 3 of them to West Germany, programmed on them, and send them back. The quality of those equipment was not good. That was the beginning of my sceptism of the "high capable" Russian technology our governments always rumble. The one original PDP11 34 we had was running flawless, the CM4's needed lot of maintenance.

@fixitalex

2 ай бұрын

@@michaeleitel7186 "Russian technology" was really different. Ministry of electronics industry, that handled CM4, got much less resources than Ministry of radio industry that handles EC series. And what was handled by Ministry of defense used to be completely different quality.

@fixitalex

2 ай бұрын

@DavesGarage is it you or somebody is tricking us?

@michaeleitel7186

2 ай бұрын

@fixitalex OK. You might know better. But what I know first hand that not only the complete plans but also the old (in bad shape) equipment to produce them was supplied. And in 82 they even where in production of their own version of VAX.

@fixitalex

2 ай бұрын

@@michaeleitel7186 There were plenty of everything. But yes by the mid 80s production and research were slowing down

@Dave's Garage - We have a complete system here in Pittsburgh that we would like to see go to a good home. Tape drives, processors, teletypes, terminals, and all original software, manuals, and every option they offered. The system was DEC support for the region because the guy I know was DEC support for this region. He was able to run and test everything on this machine set up in his home. If someone is interested in this system which is operational, we would be glad to pass it along and see it go to a good home. Are you coming to the event at the Maryland computer museum where Usagi and others are coming in May? KlodFather

This is so cool! I believe my Dad worked with the PDP-11 in the late 1970s and his experiences and tales of the early days of computer science ultimately inspired me to pursue a career in it. Great to see folks like yourself preserving such things.

This video reminds me of a good friend. He once had a working microvax in his basement, and was relentlessly curious about all things digital (and Digital).

In 1988 when I walked back to the motor control room for the 5-stand rolling mill that I had just been assigned to as an electrician, the first thing that came into view was a PDP-11/70 panel. I discovered that it was being used to interface the motor controls to the process controls at the front of the mill. Spent the next 5 years working with GE and DEC to replace the old system with a proprietary GE control and a VAX cluster.

This one brought back memories. Back in 1978, Heathkit came out with a PDP11 kit and I built one. They called it the H11. It used the LSI-11 CPU and ran the PDP-11/40 instruction set. They promised future additions to the lineup but most never came about as Heathkit was purchased by Zenith and became Zenith Data Systems and ZDS concentrated on the 8-bit computers and moved away from kits. I never did much with the H11 but I did end up representing ZDS for service in my market for several years.

@b43xoit

2 ай бұрын

I had a Heath-Zenith computer that looked like (and mostly was, volume-wise) a terminal. I guess there must have been a floppy drive. The computer ran FORTH. The CPU was tied up whenever I/O was happening.

I saw my first PDP 11 at the Hughs Missile Systems group in Canoga Park CA in 1976. I had a friend that was doing a summer internship there so he showed me around the place then showed me the 11-70. Then we played M-Trek (multi-user Startrek) on it heh.

I used to study and work using various PDP-11 systems using IAS and RSX-11 about 47 years ago. I also used briefly a Russian copy, SM system. VAX systems I mainly used just as a programmer. These were the first systems I learned in more detail. Remembering them now brings back many memories.

@MrEdwardhartmann

2 ай бұрын

There aren't very many IAS people out there. I worked at the Pentagon and a bunch of other military locations around the DC area maintaining PDP11/45 , 11/70 and Vax systems and our contract maintained the IAS operating system for the military. But I was a hardware guy, so I was more into the assembly language than the OS. The PDP instruction set was a work of art. A lot of people look down on the octal representation that DEC chose, but the layout of the instructions just required it. The fact that you could read a crash dump and understand what the code was doing from the numbers because it was so well laid out was just amazing.

@just42tube

2 ай бұрын

@@MrEdwardhartmann I studied in a university where they received PDP-11/70 in the first year of my studies. It was the first DEC equipment there, I think. It was used as a general use timesharing machine running IAS. After that other DEC PDP-11 systems started arriving to different departments own use in their laboratories. There where already some other mini computers but DEC sales was more success at handling university customers. Then VAX systems started arriving.

@just42tube

2 ай бұрын

@@MrEdwardhartmann I like pdp11 instruction set and assembler because it was so easy to understand. I too approached IT from the bottom up. I had at least the impression that I could understand it from transistors to logical ports to processing units up to binary code. Later processors, and software, have become so complicated that such clarity isn't easily achievable.

Hi Dave, what a great video and accomplishment. I was introduced to a PDP8 late in the 70s. We were allowed to enter a programs, line by line via the switch interface and the load switch. Once done we would set the starting point and execute the run switch and watched it work it's magic. I had decided at age 13 that computers were what I was going to work on and started a deep dive into electronics. I obtained a complete motherboard from a computer that developed the SOL-100. Dabbled with Radio Shack electronic digital clock kits and found a design flaw in there PCB. Once I corrected the connections my clock worked and still runs today. The company I went to work for (employee 15), Summa Four (bought by CISCO in the late 90s) while in college that used extensively the Rockwell 6502 and the CP/M operating system to compile and developed the code for our digital central office replacement for rural telephone companies with stepper switches. I have been able to be exposed to a lot of cool things. But your PDP11 project is the cats meow. Thank you for videos. Keep them coming. I loved Zork!

Had a PDP-1 in the Air Force, 1967. It was used with Basic on a 5 level tape to run a classified program to produce a another classified 5 level tape to run on an analog computer.

I used to develop custom cards and device drivers on the 11/70. Thanks for the great memories!

Great memories. I used a PDP11/40 or 45 (with front panel lights and switches) at school in the late 1970s. Loved playing Star Trek on it. Then got a job that had a late model PDP 11/70 with the remote console (No front panel lights and switches) we later acquired another 11/70 with the front panel lights and switches. It ran RSTS/E. I run both RSTS/E and RSX-11M on the simh emulator.

Got to use my first one as a sophomore in high school, 1980. It was life changing. Thanks, Mr. Russel, RIP.

you still amaze me with how our 2 careers paralleled each other. You went software and I was hardware. I also cut my teeth on a PDP 11 back in college . At 1st it was the 1108 and then 1103. I then worked as a user consultant for digital equipment for a pharmaceutical company for a summer.

Hi Dave, a fun video bringing back lots of memories of my time at DEC. Started with DEC October 6, 1976 (after three years with Honeywell Information Systems on 200 series and Honeywell Bull G50s) in Computer Special System (R&D control system), I was the first one to get an 11/23 module to develop control system hanging off the Qbus. I was offered to be a remote field service representative, supporting PDP11s, the whole gambit of the 11 family, and PDP 8s, I eventually was handed the opportunity to support DECsystems 10 and 20s. DEC was an awesome company to work for, they had terrific products, field service was one of the if not the best in the world, Customer First attitude. One could find many career moves, I did field management, sales and ended in FS Business / Product Line Management.

I remember i took classes at suffolk coummunity college, as i was in HS. They had a 11/34 in the late 70s PDP 11/34 i remember programming in basic then learned about the game on it dungeon remeber the scret code XYZZY , written i think by david ahl. A few months later got to meet him at SCC for a HS kid was great. I also remember they allowed me to reboot it was a combination turning a dialk and entering one a lcd screen a location of the tape or hard drive. .. was fun days...

Ahh.. PDP-11/73, running as the core of a Crosfield Studio system... Warm memories.

I had an LSI-11 with all the lights. At work I had 11-45’s, 11-60’s, 11-70’s and VAX’s. They were used in multiprocessor links to simulate radars (with hardware in the loop), aircraft and missiles for critical-time (solve x equations in less than y time) for EW work. At home I had the LSI-11 and RSX software with FORTRAN for my PhD work. Of course my fellow students would use it too for there work. I loved the machine!

Hi, Dave. For reproducing the bezel, you could hire a high resolution 3D scanner, maybe? The worst that could happen to the original is getting sprayed with the washable white powdery stuff that helps the surface to scan. You could then get a 3D print made, prep it with superglue and sanding so that it matches the scan as closely as possible (verifiable with a scan) and then use the print to make a mold for proper urethane resin casting.

@scottbaeder37

2 ай бұрын

or just use the 3d print.😃

@gerryjamesedwards1227

2 ай бұрын

@@scottbaeder37 that's that half-assed option.

Oh I loved the PDP11 instruction set (esp. SOB).

@b43xoit

2 ай бұрын

mov -(pc), -(pc) 013737 maybe

We had PDP-11 at the local Boy's Club in the late 1970s... could play all those old games- trek52, lunar lander, Zork, etc., or even learn BASIC. By the time the 1980s came around, DEC had put VAXes in our local schools.

As a Field Engineer for Motorola back in the late 1990's, I was sent to the Hawley Earth Station in Pennsylvania. The complex is nestled in the hills around Lake Wallenpaupack. I was there to install a digital satellite television system, which was just prior to updating all of television in North America to digital and HD from the NTSC standard. But that is a different story. While installing racks of processing equipment, I took time each day to take my breaks and lunch by spending time outside the building. Outside the data center doors, planted in the grass was what I recognized as a PDP-11. The variety of which, I could not say. The packrat in me wanted to bring it home or at least contact my boss from a previous job, who was also a great mentor. Brad had mentioned learning on a PDP-11 in college. I recall taking a photo to show him, which is on any of countless rolls of film I had from those days. This video by Dave reminded me of that trip and finding the PDP-11 lavishing in the rainy weather and wishing I had more knowledge of that kind of hardware.

Wow, that’s so sweet! PDP-11s were wonderful machines! Really well done and thanks for sharing this!

Absolutely BRILLIANT! I enjoyed your video on my big screen in 4K so much that it quenched my thirst of having to buy my own, and you saved me from overcrowding my apartment. THANK YOU! :)

Memories are coming back to me how I learned programming (both Macro-11 and Fortran 4) in the late 70s on a PDP 11/40 running RSX-11M. You definitely learned how to write small code! I loved that machine.

Now that you have a PDP-11 with a front panel, here's my suggestion for your next project if you just want to fool around: - Zero out the real or virtual disk drive. - Use the panel to deposit a minimal FORTH interpreter. - Program in FORTH from a terminal to implement whatever operating-system aspect you feel is most sorely missing if you want to program an application that you judge useful or interesting.

I was a DEC FS employee, started in '78, I was trained in Bedford, Mass on all PDP-11's. One system you might have liked was a 11/72, yes 72! It was two 11/70's with common memory in the basement in Bedford. It was very cool. Also, those panels you have could have been saved because DEC FS routinely replaced them with a Remote Diagnosis front panel that did not have switches and all the lights. It was connected to DEC in Colorado Springs. We did not have what is now self-tests at power up time, but the RDC could be into the machine while I was dispatching to remediate, a very different time than remediation now.

I was working in a "DEC shop" in the '80s, and we had a service contract. About once every two weeks one PDP-11 would just stop. The DEC serviceman would be called. He knew exactly what to do as the same board always needed replacement. Finally, an employee called me as he knew something was "off." It turned out to be a cold solder joint on the backplane. Vibration would break the power connection after a while. The boards weren't bad. The only person I impressed was the user of the computer! 😊

Thanks for the flash from the past. I learned machine code and assembly language on a PDP 11 40, and later worked with a PDP 11 4 in a mold factory. Now I really feel old and wise, though no one seems to see the wise part.

We had an 11/45 in our hackerspace back in the day. You could totally setup, run, and maintain a big PDP at your present skill and spend levels. We have faith in you, Dave. :)

@hessex1899

2 ай бұрын

Haramzada scammer :P

I was introduced to the PDP-11/20 in 1970 as a hardware design engineer. In those days the only interface the PDP came with was the serial controller for the ASR-33 teletype which was used to load the bootstrap and debug programs for development of the disk, tape, printer, and card reader controllers we developed. I continued with PDP's up to and including the Vax-11/750 where the 8-disk controller was my last hardware project. I 'jumped ship' to the software side as a system manager for large clusters until 2006. I still have LSI-11/23+ and 11/73+, as well as a 4 Micro-VAX cluster and an Alpha in storage....'till I get a bigger place. I particularly enjoyed writing assembly language programs for both PDP and VAX's. Those were the days! (I still have a Plessey 16K core memory for a UNIBUS PDP.)

Brings back memories. I remember the slow process of writing a program using the PDP-11 panel just like yours. I worked at DEC in Alkuberky decades ago. Thanks for the memories.

Ah memories. Back in the day, I linked six PDP 11's together in a parallel computing system to simulate aircraft dynamics. Now I could probably do the same problem on an SBC...or my phone for that matter.

My first 'personal computer'. Loved it and RSX-11M. Writing overlay descriptions was so much fun.

Cool video Dave - ex-DEC Field Service Engineer here and while I was primarily a VAX Systems Engineer they had 11/03 as a boot front end. I was also KI/KL10 (PDP-10) trained - monster 36 bit behemoths that used an 11/44 as it's front end processor for boot and comms like serial, printer, ethernet.. We used to carry out preventative maintenance on these weekly, mostly replacing burntout light bulbs on the 768kb of core memory! I would love to see a DECSystem 1090 or 2065 in your shop :)

We had a PDP11/34 with two RL-01 disc drives that came with the Datacolor spectrophotometer and color matching software for our paint lab in the late 1970s. I recall the system came with close to a dozen large 3-ring binders of documentation and one disc (16" diameter) cost $200. We learned a lot about programming during those days. The complete system cost more than $50K.

Thanks for your excellent PDP blog Dave, it brought back a lot of memories. In the 80s I worked as an electronics tech for a UK research group that used a PDP11 with an A to D card to collect and process experimental data. The Prof who headed the group was not satisfied with the setup so he set about rewriting the operating system to enhance its performance with the A to D. He was so successful that DEC sent two engineers from the States to see how the hell he did it! In the early 90s the PDP was scrapped to make way for an IBM 286 PC based system. I have always regretted not rescuing the PDP, but I don't think my wife would have welcomed it into our living room! I did remove the 16K x 16 core store board before it went which I still have in my collection of electronic artifacts.

Very fun. I have a soft spot in my heart for the various IMSAI and Vector computers you had to boot by toggling a bunch of switches and then got to enjoy the light show. Oh, and huge rotary drum line printers with the fan-fold paper that could actually murder you to death if you did something stupid like getting a tie caught in it with the lid open. For fun you could start a print job with nothing but CTRL-Ls (form feed) and watch people freak out. Those things could spit out something like 10 pages a second.

I first programmed a LINC-8 in the late 60s in university. Two full size cabinets. DEC tape and analog inputs. (This was a vet research lab) To boot it you had to use the front panel switches to enter the boot program into 12 bit core memory ... Yes, real core 4K

The most blinkenlights I ever saw was (in the Navy) a room containing four CDC-1604 mainframes. Open the panels, turn out the room lights, and enjoy the show.

Back in the late '70s, my student job was in a behavioral psychology lab. The post-doc I worked for ran his experiments on a PDP-8E (yeah, I know, 12 bits vs 16) using.a process control language called SKED, and analyzed the data using a FORTRAN program. The 8E had those cool flippy switches, and you booted it by entering instructions into memory locations 30 and 31 (6031 and 5035 octal IIRC, which I probably don't) and hitting run. Good times. Wound up working on the real-time stuff for the SKED language.

Amazing system, Dave. Watching the instructions getting executed on the terminal as the LEDs light up is a vista into watching the processor functioning in real time!

My first computer experience was doing 9 track backups at age 6 standing on a chair and I worked the PDP1170 running RSTS. My parent's owned the company Spartin Systems back in the 70's through the 90's where they bought, sold and leased time on the PDP11's . I remember adjusting tape head alignment with my Swiss army knife and dripping wax on the pot switch so it wouldn't move with the vibrations.

We used pdp-11s for controlling electrical high-voltage substations from 1975 to about 1990. The last have been switched off because people feared the millennium bug. For control software, we used assembly language software which was very easy to write and read. Much better than most other systems.

Great episode. I cut my teeth on PDP-11/70s, ‘44s and the mini ‘23s, before moving on to VAX’s and Alpha’s. Most were running RSTS/E and VMS with the odd Ultrix install. I would program the ‘44s using octal on the front panel to boot to a 10Mb hard drive the size of a washing machine.

I worked on these before I knew anything about computers! If it’s working don’t touch it! Nice video! Especially the home system in the living room!

I don't know _why_ (I really DON'T) I found this SO compelling ! Maybe its because my first CAD assignment ran on a PDP-8E and I fell in love with it . I We rotated shifts , my terminal being one of 8 in a smoke-glass encased room . Fond memories !

Somewhere on the DECUS PDP11 tapes (circa ‘79/‘80) are my MACRO-11 programs that emulates RSX-11M, 11D, RSTS, led rotating patterns. They are all different. Why? So that I could confuse DEC engineers into thinking a different OS was actually running on a PDP11/70. So much fun! Gladly I went on to write more useful code during my s/w career! (I think)

@b43xoit

2 ай бұрын

Yeah, it was also possible on Unix to write idle-lights programs.

I had VAX11/730 at home as a teenager and then later on in my own flat the same plus a 11/750 great for winter time - 20mins up and its shorts and t-shirt weather and drinking pina coladas

I just auto-like a Dave's garage video before I even get past the cold open as a matter of course, love your content

I loved the machine. The assembly code was a precursor to C++ and Unix. I wrote my own realtime OS to simulate radars, aircraft, Gatling guns and missiles with hardware and people in the loop.

@laustinspeiss

2 ай бұрын

There’s a lot that modern coders could learn from the PDP-11 design. Just bump it forward 50 years !

@b43xoit

2 ай бұрын

In particular, a PDP-11 addressing mode inspired the postfix `++` operator, which made its way into the name "C++".

We used PDP-11 computers in mid '70's where I worked.

Takes me back to my first summer job in college! Thanks for the great video!

Less than a year after I started my first real job out of college I was made administrator of the sites VAX cluster. I fondly remember the shelves full of extremely detailed orange binders full of documentation for VMS and the system itself. The neighboring site had a couple of 11/780's still running which I helped out with occasionally but they were MUCH bigger and noisier and hotter than my micro-Vaxen. Plus, I had much bigger disk drives - a full 6o MB for the O/S, and a 600MB (14 inch naturally) re-writable optical disk. Very cutting edge for 1989. Along with the normal 9 track tape drive and tk-50. I discovered - to my chagrin - about a year into the job that VMS would happily fill the O/S disk until the system crashed and was unbootable by writing to log files. No one had ever told me I needed to purge them manually on a schedule..... I can tell you booting enough of VMS from a tk-50 tape to purge the logs is painful and takes hours.... Undoubtedly the best documented computer I've ever used.

The first computer I used was a PDP-8 that my High School rented. The I/O device was a Teletype with paper tape reader/punch. All the trig functions had to be deleted to make space to run a program.

In the mid-1980s I was responsible for a PDP-11/45 on our kibbutz. It ran RSX-11 and supported manufacturing systems for a plastics factory and a concrete plant, as well as accounting and other functions for the kibbutz as a whole. I put in a phone line to my apartment (I also maintained the phone system there) and wrote terminal programs for my Sinclair QL computer, first emulating the VT52 and then the VT100. DEC documentation was great and I learned so much in those days!

I worked on a PDP-11 for a while, after cutting my teeth on a Sperry-Univac - what a revelation to have my very own VT100 and not have to punch cards or find a hand-trolley for the compiler error report.

In 78' I was building and selling IMSAI 8080's - thought those were amazing with paddle switches and LED's and your PDP no doubt inspired it!

I remember the PDP-11, was used for industrial automation purposes at my workplace in Norway

Hey Dave! Its a small world. I think that we're the same age and I grew up in Regina too. It was really shocking to see the photo in this video as I worked with Gary and Roe at a little Commodore computer store in the basement of 1942 Hamilton Street in 1983. They were hired to build some software for use on Commodore SuperPETs...we'd burn it on to EEPROMS and erase them with a similarly ultraviolet light as Kramer encountered! I hope those guys are doing well, I've not seen them in 40 years! Thanks for your videos, they are great!

Blinking lights, lots of switches and a few knobs... What 12 year old (or any year old) could resist wanting one? Dave is fortunate to have the knowledge and the means even if a few decades after first sight.

@brianvogt8125

2 ай бұрын

Lights & switches were our interface to the bits where important things happened. Without them, understanding would have been abstract.

You have certainly tapped a rich vein of retired a DEC users who are trying to figure out where the years went! What a pleasure to see this stuff again. 😊

All this PDP stuff is a little bit before my time, but I distinctly remember as a kid taking books out the library in the early 90s and staring at the pictures of those massive banks of storage and processors. It’s super interesting to have more context for how those systems operated. Great video as usual!

First mainframe I ever worked on during my Marine Corps career was the PDP-11/70. Give me a few minutes with one and I might actually remember how to boot one from a tape drive.

Brings back memories. Worked for a bank in the late 70s. We need to replace our check processing system and we spent months deciding between 3 options. IBM, Burroughs, and REI with a PDP-11. After determining the weights of the features of each system. After evaluating and assigning a number for each feature we picked a winner. In the end leadership picked option 4 (nothing we evaluated). I think the deal was made on the golf course. That was my experience with Unix and the PDP-11. Finally got into Unix systems in the early 90s when the client/server and data warehouse’s became a thing. Spent time going to Microsoft working with other vendors on Windows DNA FS.

In 1984 I learnt to program in Fortran77 on a PDP11 running VMS. I still use those skills I learned then today …

This sends me back. Back in the late 70's and early 80's I got my start on PDP-11's. I started out on a PDP-11/40 with 112 KW of main memory. For some reason it didn't have a full load of 124 KW of main memory (memory was counted in 16-bit words, not 8-bit bytes). It had dual 2.5 MB RK05 disks and a couple of 1600 BPI tape drives and a customized BB-11 data acquisition box. It also had the original GT-40 graphics display (on which you could run the original Lunar Lander game). It was officially used to collect and display data from an early cryogenic gravity wave detector. Quite the beast. In order to boot the beast, you had to toggle in the correct starting address on the Boot ROM, depending on whether you wanted to boot from disk 0 or 1 or even tape drive 0 (the latter was used to system updates or loading diagnostics). The Boot ROM was a sight to behold. It was a "6-high" Unibus board covered in "bits" literally. It had zero ohm resistors soldered all over it in an array. Each resistor was a "1" and if it was missing, it was a "0". So the boot code was "soldered" in by "hand" and extremely limited in size. But at least I know what a bit looks like! This was better than the PDP-11/10 a buddy of mine had down the hall. It didn't even have a boot ROM, so you had to toggle in each instruction with the front switches and deposit it in memory. The address would auto-increment to the next address and then you toggled in the next instruction. At one point you toggled in whether you were booting the unit 0 or 1 of the RX02 8-inch floppies the system used as the main disk for its RT-11 Operating System. There was a cheat sheet with 30 or so boot code instructions on it. The rule of thumb was you if it didn't boot, you tried it again from scratch. If it didn't work the second time, you had to deposit all zeros in all of memory for the first 1000 (octal) words and try it again. If that didn't work, you let your boss try (although he was generally useless on the "damn thing"). When all else fails, you'd walk down the hall to the electronic shop and get one of them to try and/or start poking at it with a multimeter. Both the 11/10 and 11/40 had similar, but simpler, front panels to an 11/70, but their lights didn't cycle on idle like the 11/70. Depending on which OS you loaded, the lights rotated differently. RT-11 rotated them Left to Right, RSX-11M, rotated them Outside to Middle, like you show on this video, and RSTS rotated them Right to Left if memory serves me after all these years. (Edit: On the 11/70 the idle loop on RSX-11M-PLUS (or maybe RSTS) used Supervisor Mode addressing to run the light pattern across on the Data LEDs then Back on the Address LEDs making a full circle. This was the only place in the OS code that used Supervisor Address mode. It's been a long while since then) This came in handy later when I "Managed" four huge 11/70s after I graduated for the corporate HQ of a big manufacturing company. They usually ran RSTS for data entry (as a front end for the big IBM mainframes on the other end of the huge computer room) and word processing, too. One of them was a spare that I would boot RSX on to support the real time systems I supported at various plants "out in the field". Just one glance at the front panel would tell you which OS was loaded and how busy the systems were. The faster the lights spun, the less the load was.

Back down memory lane!

Takes me way back, Reed College - I arrived as a Freshman in 1982. Their PDP-11/70 handled the load for administration, and had a student lab with a mix of Tektronix and VT-100 terminals. Learned to format my term papers with nroff/troff, and we were required to buy our own 8" floppies for personal storage, and ribbons for the daisy wheel printer we had to get "special dispensation" to access for our final output. All this was a great foundation for the eventual development of my IT career, and also some great memories. Note Reed had at the time had the only research nuclear reactor (10 watts of power!) on any college campus. A student run project was completed to create an open air laser link back to the PDP-11 from the reactor to facilitate data processing, pretty unique at the time. Also very pretty in the fog!

@nufosmatic

2 ай бұрын

I was a roff-ing fool once upon a time...