Paul Guido @RadioTeacher - Booting a PDP-11/70 From Virtual Paper-tape

okay okay so hello cyber refreshes so welcome to be sighs 2019 and I want to introduce mr. Paul he's a pioneer in network security engineer he's been working for more than 30 years and the currently is he working as senior network engineer in Broadway Bank so please welcome mr. Paul thank you all very much yeah I don't feel like a dinosaur in computing so I'm kind of showing off dinosaur type technology here today you might have to zoom in the camera down the road when we kind of show off the interface but let me let's talk about it first the Digital Equipment Corporation made computers starting in the 1960s like most computer companies the engineers kind of some of

them didn't see eye to eye with management they broke off and made their own computer company called data general and it there was always this kind of like unofficial like rivalry between data general and and and dec computer Digital Equipment Corporation it was really funny the DG guys were nuts and in the data in the deck guys were quite prim and proper not quite IBM Freeman proper but pretty prim and proper and in what caused the rift between the two engineer groups was they didn't want to go to a hex system for the computer data general did they wanted to change the the base that the computer ran on so that was like the big

engineering riff in the 1960s between those particular computing companies so the pdp-11 70 was originally introduced in 1975 it is a 16-bit word size 22 bit physical address size and virtual address size of 16 bits yeah it could directly address only four megabytes of memory that's it so if you needed something this gentleman and sitting up in the front here is nodding his head because he actually was a were you an operator sir okay so am i right about the data general versus Dec thing and by the way I knew some data general guys and they were rarely sober I'm just letting you know and look of the deck guy laughing yeah exactly it these buses are pre

forerunners the universe mass bus memory and memory bus was an innovative thing for the 1170 or the actually the the pdp-11 computers were custom-built and there were no way to expand the buses of those computers for the most part they tried to make a plug-in type arrangement where you could plug in a paper tape reader and/or paper tape writer yeah they used to literally write ones and zeros on strips of paper and then would feed that back through and that could contain the operating system have you ever had a core dump that you've done have you ever seen that why did they call it a core dump because these things ran on core memory tiny little doughnuts

of magnetic material with wires running through them in a grid arrangement that were stacked in layers and that magnetic memory that magnetic pulse would stay in it so they could turn it off like a USB Drive would remember what you had core memory will keep that magnetic material in that one and zero now it was destructive right it's a short of yours cat of make magnetic technology right is it there is it not there let's check oh I just killed it so a twisted one or zero so you could turn that thing back on so you could actually turn the pdp-11 off turn it back on and it would remember the operating system that it had running on

it and exactly the state it was at at the time so that was an advantage of core memory which is different than the other memory technologies that were available and weren't available at the time so yeah so a core dump really that we talked about today was literally talking about tiny little donuts with wires running through them that's core memory if you ever seen it it's absolutely the most beautiful work of art for electronics it looks like a tiny little carpet because of the way it's weave together a matter of fact they they had special teams of women for the most part that could see and manipulate those tiny little wires through those tiny little cores to make

those things so ads acting right every single time just unbelievable dedication and skill to be able to build those memory cores and that's exactly the same kind of memory cores that were used on the Apollo missions and stuff it's I don't know crazy notable achievements of the pdp-11 so a number of operating systems were designed for the pdp-11 this this replica of the pdp-11 runs ten different operating systems out of the box there's a set of downloads you can do for it and you can run multiple multi user and single user type operating systems including unix 2.11 there is a video I saw recently where they were talking about UNIX 2.11 versus versus modern UNIX and they were talking

about all the interdependencies of libraries of an individual program when you do an LS right and you're doing just a list you know how many dependencies that causes how many libraries that actually calls back then it was literally like twelve lines of code that's it it's really short and you can go on and on and on and look at that to try and see the historic differences but not to be I think I got that in a little bit later slide so both C programming UNIX all first ran on the pdp-11 a matter fact C was like custom made to take advantages of the processor that was built into the pdp-11 over 600,000 pdp-11 s were sold in 1995

I'm at a Shell oil and gas many exploration Department that was down in the South Texas coast I was doing some work on their Novell servers yeah another set of dinosaurs that don't exist and I looked over in the room and there's a two racks and one of them has a pdp-11 in it and next to it was the rack that had dispatch in it so think about round platters about the size of I'd say records but that's even the old technology now to your right in the records 12-inch I don't know big discs four or five stacks of discs and they take these discs and put him in the machine and pray to God they didn't

get any dust on them so they wouldn't scratch them because that would take the meteorite off of them and then it would run the disk those were five megabytes those disks what this particular computer did was absolutely pedestrian right systems out there would call into it via phone modem back in 95 and say my tank is full and they'd send a truck over there and they'd empty the tank pretty straightforward stuff but that's kind of what it was used for it was just a workaholic it would just sit there and crunch out this stuff and they were like you know we could replace this thing but it's running you know and and it's not like the code is hard either it's pretty

straightforward code that they had for the modems to be able to get all that to work so these things were just absolute workhorse um I'm gonna see if I can pop up a video here yeah of course I trust this it's not my laptop sorry dude no oh here groan and there I got it yeah so I don't know if that's going to have audio or not but oh it's not up oh oh it's not up there one second let me swing it to the other oh

you're the whole thing right right yeah and oh and wait where's my no I did it again why is it Oh cuz I got to do it there oh yeah that's it because I'm sorry should I stop the slideshow that's what I got to do is to go back to the slideshow click and escape there we go yeah and now let's see if I can do that yeah No okay let's do the old tap thing there we go so here's a gentleman that just released this video like six days ago and it's so awesome I'll kind of get to talk through let me go ahead and grab the mic again here in a second I'll

start back the beginning so what this gentleman is doing is he's going to load what is it rt-11 as an operating system so what you first have to start with as you go and you go into the sim program that's on here which I'm going to talk about in a moment and you tell it don't boot an operating system or don't even boot blinky lights this is just a running program that says run blinky lights and so he's going to go ahead is did I stop it and I stopped it no it's running good okay and so he's gonna grab an address and I think it's what and see which one he's gonna get here I don't have audio

but it should be coming up pretty soon because he's he's got to put in a lot of hex not hex I'm sorry octal commands so you see this suit that's the way the switches are aligned so he stops the operating system and then he's going to start loading things there's like down here there's three of one color and then three of another and three of another and three of another and three of another this computer is octal so it's space is 0 through 7 that's it there's no hex up to F there's no buying it well there is binary underneath that fall but it's octal 0 through 7 so that's why the switches are arranged in threes in

different colors so we can go ahead and count across so if he needs to put in a thousand that means the second set of red over he's got to do a 1 and then 0 0 0 on the next sets of threes and that would be a thousand or the equivalent of one zero zero zero so so he's flipping up different addresses and then he's going to go ahead and flip the load switch and load that in there and as he does that it's going to sequence across the top which instruction he's putting in when he's done he's going to hit start I'll go ahead and forward it after he gets the operating system fully in when kind of get it

there and then he's going to flip up the start button which is at the end and when he does it's going to go ahead and fire up that rt-11 operating system so he's looking and loading specific memory addresses in in the computer to make that happen and here comes start boom and now he's running rt-11 it's I was going to do this but you mess up one code switch while you're trying to do this in a live demo and you know what's going to happen it will fail every time that's why I had flad this gentleman put up this wonderful video okay enough of that back here and a five and do do do do do don't

do okay all that is wonderful because of sim H sim H a guy named Roberts but Nick is a former deck engineer started making this multi operating system system it also runs on Windows and other operating systems this is running on a Raspberry Pi on the back of this interface this is about 60% scale of the original face panel that was there it can emulate over 40 different operating systems and you've got to get hub repository there so if you wanted to emulate an Atari or you want to emulate an IBM whatever system three you happen to have old code from those things this guy's program will run that natively so there was this wonderful

thing out there right you can run it like a PDP 11 or a PDP one or a PDP 11 and 10 all these different versions that was really neat but that was all in software right it's like running a VM and like a VM you don't have that physical connection to the computer right back when I was running old compact computers and stuff you had a physical connection to that disks array that you're building there right you had physical you could touch it nowadays with VMs yeah somebody asked hey where's that computer running that's uh you know under PCI and I go it's here somewhere in this general area of rax you know cuz I can't tell where the VM

moved to and it could remove and rebalance at any time and they were like what you know auditors the official site for sem h is sem h trailing edge comm if you don't want to get that plus if you want to the presentation and another presentation i have i've got pastebin.com i'm i'm radio teacher on on twitter as it said at the very beginning so if you go pastebin.com /u for user / radio teacher you'll see b-sides 2019 and they'll be direct links to these presentations there so you can go get them so that's the crazy guy that makes the sim program right this is the crazy guy that makes this interface he first made just a standard little computer

interface that was like a little hex computer I can't even describe it then he decided to ramp up his game and he made this replica of a PDP 8 and once again it tied back to the sim program so it was a physical representation where you actually could have switches that actually did something that controlled the VM on the inside which was awesome stepped up his game one more and he just came out with this back in October of last year if you do any kind of security podcast one of the ones I would recommend highly especially if you're just starting out is called security now it's got Steve Gibson in it Steve had built and written articles and

everything for as long as I can remember back in the 80s I was reading his works in info world and I was just in trolled because every time I would InfoWorld I would look for his articles now I listened to his two-hour plus podcast every week just to try and keep up with what's going on Omar sitting there shaking his head and not only is he a very he's a very patient teacher and he talks about things in very technical terms but in easy to understand terms when this thing came out he was like gotta have one and and Oscar this Swedish gentleman he did the plastic injection molding all of the switch information how to build this

thing there's like 64 LEDs in this thing that make it work and the switches have to go in in a very specific order so they give you actually a template yeah sorry about that moved a little bit on you they give you a specific template on how to put these switches in and it's really hard to get them perfectly straight I did a pretty good job and stuff but if I wanted to like once again I could I could flip the switches and stop it and start it let's see here's halt and that stops it and I could go ahead and start it again boom and stuff so this is a physically controlling the VM that's running in memory on a

Raspberry Pi on the inside it's a wonderful piece of technology it's only about a if you want to build one I recommend it I think it's $250 it all-in-all was shipping everything it's about three hundred dollars or so because of its coming out of Sweden no Sweden no Switzerland Switzerland as where Oscar lives so it came by you know Swiss Post it was really kind of cool I don't get to mentioning some Swiss post so and he's a really nice guy they do production runs on these things and occasionally this isn't really a moneymaker for him this is expensive to build all of this injection molding stuff and the circuit boards and everything else is it perfect no but

it's pretty darn close now somebody has stepped up Oscar's game with this piece of hardware there's something called a field programmable gate array with that type of hardware you can emulate things you can actually go in program what a computer does and so there are people out there that have got a field programmable gate array that can actually emulate a pdp-11 and then what they did is they actually interfaced it to this so it's got a real console cable port it's got real manifestations or everything else the trick was how do you get that field programmable gate array to hook up to this guy because it's voltages are different than the voltages that this thing was designed for the trick was

putting a hundred ohm resistor across a couple of resistors that were there on the board done but they figured it out just literally last week so there's an active forum going on for this device and his future devices that he's making his next one it's really stupid but I don't know what the guys who would dec were thinking but there was the PDP one and then the PDP a then in the pdp-10 wait no the 11 the 10 came after the the 11 yeah what really guys and that one is a 36 bit computer yeah just to keep you on your toes right and it's a much bigger computer too it's physically it was like

a desk and that's the next one that Oscars building he's designing the pdp-10 right now I had a picture of the original look he got the colors just right in the way that this thing's laid out it's amazing it's the same feel and everything this is the pdp-11 website for oscar and once again you can get those presentations off of my pastebin site it got a wonderful bright up in magpie a matter of fact it was rated a 9 of 10 for as a you know an extension for the Raspberry Pi let me turn this thing around since you got the video so close right so you can see the Raspberry Pi in there I've got a keyboard get attached

to it in a mouse but I really don't need it to run the thing and then this is a rs-232 port for it as well so I can go ahead and get on the console of it as well but to make that port work I had to populate some chips and compacity up here and then bring in some cabling to to make that function so so get a kit heat up a soldering iron and it's all about LEDs and switches on this baby like I said there's about sixty four LEDs and there's a lot of switches and the switches have to go in in a very specific order or they won't toggle up as you would normally have that feel or

load down or start down or address up so once again that Raspberry Pi and simay can just bring out and physically manifest what it was like to have at your disposal a pdp-11 70 and then they can also run other pdp-11 versions but of course their interfaces were slightly different so the other thing there's a couple of hidden commands in here these actually push to have extra switches in them that was not a function of the original pdp-11 but that was something so they can control more information on sem h to load other operating systems and stuff so in development up you ain't got it yet drivers are being ripped written right now to emulate paper terminals so the

original terminals didn't have display tube x' or anything for characters it was literally it looked like a typewriter piece of paper would come out that's a different kind of feel than one that's got a terminal back space isn't back space there is no back space that the carriage doesn't go that way the carriage only goes this way it's a physical writing device so they are working to emulate that and actually get that to work with typewriters and stuff they're interfacing them to the device yeah they've got a web server running on UNIX 211 and they also have web running I think on rt-11 as well their their writing software for those old operating systems a matter of fact some

crazy person actually has one of those web servers on the internet running on the PI on that's emulating UNIX 211 it's very simple so once again hopefully the attack surface is light yeah that's what I'm saying a 36 bit PDP 11 s in the offing and then this is that video that I showed you earlier do you all have any questions about all this stuff I know it's a lot to take in to think that some body crazy enough to go you know it's nice to have a virtual machine that emulates these things but wouldn't it be nice to actually touch the computer the way it was so any questions about this or anything yes Omar true but it's also

exploratory right so if you wanted to learn how to write drivers do you want to learn how to write a video driver than 64-bit or do you want to learn how to run a write a paper tape driver that's 16-bit right so it's the same kind of concepts right but you're going to be doing it in machine language at a much simpler machine than it would then hopefully you would be doing today yeah and it wouldn't and you know what it's it's non explodable you can't blow it up and if you do no one's gonna care you just go back to a previous backup of your PI and you keep going on that's right yeah yeah it's like oh my driver

took out linic or Raspberry Pi or raspberry n' or or sim h fine just go to the github download it all start over have a nice day so as someone that's just learning how to code what a great experience for someone to code in and you know what it's like teaching kids music teaching kids octal wouldn't be a bad plan either you're right because knowing how to do things other than hex or binary or decimal to have that other math base in your head gives you a capability that hopefully gets you where you can thank better on your feet because things are not so foreign for you for an experience and stuff oh wow I'm running out of time I see they're

getting ready to pull a hook on me I'm sorry yes absolutely it does keep oh yeah so the the question is from it's good for I'm a hobbyist point of view but what what do I think about it from a historical perspective that's exactly why I like it I when I grew up I was reading magazines in the 70s and this guy was like the bomb this was like oh my god what a computer it's like racks of supercomputers today would be to look at or whatever operating systems that are out there that they can do this and once again before we we started I talked about it to really emulate the feel of this you

also have to have three heaters running and a couple of vacuum cleaners right because you have to get the feel and the sound of what this thing was like right and that's about what it would be like it loud and it would be hot so I'm running out of time thank y'all very much and y'all have a great rest of the b-side San Antonio [Applause] thank you Paul so it's a