KA ITS.1651. DDT.1548.

TTY 0

You're all alone, Fair share = 86%

Welcome to ITS!

For brief information, type ?
For a list of colon commands, type :? and press Enter.
For the full info system, type :INFO and Enter.

Happy hacking!

:PRINT WHAT-TO DO

...So what to do with a mainframe at home?

We’re glad you didn’t ask. But here are some suggestions:

Day 1: place the Blinkenlights Machine in a bookcase, in the living room. Mainframes expect to be placed in the biggest room in the building. Because it is powered by a Raspberry Pi inside, you can leave the machine powered up 24/7; the electricity costs are (probably much) less than $10 per year. Mainframes prefer not to be switched off and on, and the Blinkenlights will add to the ambiance of the living room.

Be sure to attach a note next to the machine, it is a tradition to be honored:

ACHTUNG!

ALLES TURISTEN UND NONTEKNISCHEN LOOKENSPEEPERS!

DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKEN.

IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.

ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.

You could place a little 7” HDMI display next to it, showing both the system console (it replaces a noisy Teletype, which does not fit the living room idea) as well as the simulated Type 340 display tube. It could run a graphics demo (Minskytron, or Game of Life), or you could run Peek, the system status program, in graphics mode. To impress visitors.

Spend the rest of the day playing spacewar! MIT students mostly spent their CPU time that way. You can look at the source code a bit too.

Day 2: learn more about operating the ITS system – :HELP, :INFO, and the ITS wiki web pages.
But do this from the comfort of the recliner chair that no doubt graces your living room. You can lazily log in with a laptop, over wifi. The PiDP-10 will not recognise that you are faking, it believes you are legit MIT staff on a serial terminal. Make sure you master the Altmode commands, they are for the true insiders and make using ITS a lot faster.

In fact, don’t log in using a bare telnet connection, instead run the TVCON program on your laptop. Now, the PiDP-10 will think you are logging in as a MIT student over the Knight TV system, which gives you a neat graphics terminal (there’s even a spacewar written for it). The TVCON simulation program can run on the Pi itself, of course, but also on a Windows or Linux laptop. It connects over a telnet port – but again, the PiDP-10 won’t be aware of that. The Knight TV terminal system was an eminently hackable PDP-11, sharing in the PDP-10's memory space. Hack it some day to scare visitors logging in. Perhaps by putting your own logo on its login screen.

For now, though, entertain yourself a bit with early AI. Run Eliza, let her cleanse your soul with her empathetic questions. Then, run TWDEMO, the famous Shrdlu AI program that knows all about the 3D world created for it. Nice graphics, too!

Day 3: set up networking a bit more and invite friends to log in to your mainframe. They can use the TVCON terminal simulator, or just plain telnet, or ssh. Go configure. They also have the option to use one of the other terminal simulators we have. A VT-52 is not uncool. But the IMLAC simulator might be a nice option. Because now, the two of you can play Maze War together.

When the day is over, read the PDP-10 System Reference Manual or System Users Guide to learn more of the exotic CPU architecture. The manuals are excellently written, well-suited to nighttime reading.

Day 4: Realise that the PiDP-10 is made to be two hearts in one body. The Raspberry Pi is perfectly usable for whatever you want to do with it whilst the PDP-10 is also running. Make the PiDP-10 a media server, file server, web server or whatever else you want to do with a Pi at home. It’s powered up 24/7 anyway (because, as per the Day 1 entry, you don’t switch off mainframes and this one happens to be very energy efficient).

Day 5: Master the ITS command line. It’s not just a regular command line, as you know it actually is the system’s debugger. One enjoyable excursion: fire up the simulated PDP-6 on the Pi. It shares the memory of the PDP-10, and to play spacewar on the PDP-6, you have to do some shared-memory hacking on the PDP-10s debugger. You’ll become familiar with the PDP-10 and ITS’s inner gubbins and be a True Hacker.

Exploring the simulated AI Lab a bit more, you could hack into the simulated PDP-11 that runs the Knight TV terminals. It could run other things too, you know? Alternatively, to avoid annoying all your friends that by now constantly log in to play the Knight TV version of spacewar (less nice than the spacewar on the Type 340 display, but still good) with each other, fire up the GT40. It is a small PDP-11 equipped with a graphics display. Play Lunar Lander on it.

Day 6: Spend some time on the source code of Minskytron and the other graphics demos in the LARS directory. Maybe this is a good base to start from, to make your own graphics demo for the PDP-10? Programming vector (vectordot is a better description) graphics is much, much more fun than pixel graphics. Ride the electron beam! We should have a mainframe democoder competition. We will, in fact, soonish.

Day 7: Networking day. The PiDP-10 has (semi)regular FTP, telnet, etc, so setting that up is useful. It might also be time add your mainframe to the worldwide HECnet. Tunneled over the Internet, this is a worldwide network of real and simulated PDP-10s and PDP-11s. There are some slight security issues, because as you know ITS does not believe in passwords or limited user rights ;-).

Day 8: You might have seen the picture of the ARPANET as it stood in 1977. Realising that the PiDP-10 and PiDP-11 software runs fine on a ‘naked’ Pi without the PiDP Blinkenlight hardware, grab some of the other Pi’s from your drawer (just a Pi Zero is already enough) and build your own ARPANET. The simulated IMP device can be your friend.

You're pretty much up to speed now. Stay on the ITS operating system and code in C, MACRO-10, Logo, Basic, FORTRAN, perhaps Cobol. Actually, Lisp might be the better idea. I mean, it's tightly integrated to the ITS emacs editor.
It might also be time to explore the other OS, TOPS-10. You can reboot the PiDP-10 for that, and perhaps, you'd want to bring up the world's first Multi-User Dragons & Dungeons? Maybe it should be ported to ITS. See youtu.be/W_knsnwrRno, mud.fandom.com/wiki/MUD1, and www.quentin.org.uk/2018/12/08/building-mud-86-from-source . But mind you, there are dozens of these mainframe rabbit holes that you can get in to. This is just one, waiting to be picked up.

The above was written tongue-in-cheek. The networking projects are non-trivial in fact, and the HECnet option is one that we’re still investigating. It will come, but joining HECnet now will not be for everyone: because of the security issues, the HECnet team will be a bit conservative in who they allow on the main HECnet backbone. But everyone can gain basic proficiency in ITS in a couple of hours, or immediately enjoy the games and graphics demos. The fun part is – this used to be for the wizards and high priests in the early 1970s. With the huge computer experience that everyone has these days, things are not so difficult anymore!

If you get stuck with any the above things (networking!), head over to the PiDP-10 Google Group at https://groups.google.com/g/pidp-10 . You will find help there - in fact, some members from the real AI Lab.