Introduction to ITS

Table of Contents

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Introduction to the Incompatible Timesharing System (ITS)

This is the file INFO;INTRO >, which contains information that is, one hopes, useful to the beginning user. It is an attempt to answer questions that are very common to the naive user. It is not intended as 'full' documentation.

This piece of documentation is designed for use of the new ITS user, to give him or her a broad overview of the resources available on the system.

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1 How to get your terminal set properly.

This node contains very basic information about how to get help setting your terminal type properly.

To tell this machine about the type of terminal you are on, use the :TCTYP command. Typing ":TCTYP ?" at DDT (followed by a carriage return) will give info about the setting TCTYP can have. It will also point you to more complete documentation if you desire it. One of your first concerns on this machine should be telling the computer what type of terminal you have so that it can do the most effective possible job of using your terminal's features to its advantage.

TCTYP knows about many standard types of terminal. For instance, if you are on a VT52, you should just type


and all programs on the system will be able to do appropriate things with your output to take advantage of your terminal type. (":TCTYP ?" will, of course, give you all this info.)

If you find that TCTYP does not support your terminal, or the right options to make it do reasonable things with your terminal, you should also look in the INFO program under a topic called 'CRTSTY' for a description of this program. CRTSTY knows about special terminals that the operating system doesn't, and it can be of great help in making them livable. ADM, Datapoint and Datamedia, VT100, and others are in this category.

If you are getting a double-echo when you type characters, it is because either you or your host computer is in half-duplex mode. ITS expects to be echoing your characters for you as you type. To correct the problem, make sure the button marked FULL/HALF DUPLEX on your terminal is in the "FULL" position. If it already is, then try to get your host computer to stop echoing. If this fails, be sure to specify "HALF" in the list of options to TCTYP. That will tell it that you are using a half-duplex terminal and not to echo your input. All programs on ITS assume full duplex, and some are more flexible than others about the need for full duplex, but you shouldn't expect wonders from any programs that do fancy display if you are set in half-duplex mode.

(See also the TCTYP node under INFO for more complete documentation.)

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2 All about the ITS file system.

This node contains information about the ITS file system.

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2.1 What a directory is and how to see it

This node contains information about the structure of file directories on ITS.

ITS file directories are not hierarchical in nature. There are a finite number of directories, all at one level, and no subdirectories.

To see the files in a directory, use:

             :LISTF directory-name

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2.2 How to make sense out of ITS file names.

This node is designed to teach a new user how to read and understand the various formats in which file specifications can appear.

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2.2.1 The four fields of a file name and what they mean

Each file name in an ITS file specification has four fields, not all of which need to be specified (some may default), but all of which will at some time be used. This section will deal with the meaning of each field.

A file specification will normally look something like this:

             DSK: MYDIR; MYPROG NEW

and is organized into four fields. The structure of the above file specification is as follows:

             <device>: <directory>; <file-name1> <file-name2>

where <device> = DSK, <directory> = MYDIR, <file-name1> = MYPROG, and <file-name2> = NEW.

What follows is a description of the four fields of a file name:

<device> - the hardware/software device on which the file lives. For the naive user this should always be DSK, which is the normal disk packs. The device is DSK by default, so, if you pretend it isn't there, and if you leave it out of every file name that you ever deal with, then the whole world should continue to function properly.

<directory> - the name of the directory (if applicable). Most devices (like DSK for example) do use directories of some sort.

<file-name1> - the first 1-6 characters of the file name.

<file-name2> - the second 1-6 characters of the file name.

To specify files to DDT (the top-level job that you are running) – and to almost any other job, since all try to adhere to the convention – you should type:

<device>:<directory>;<file-name1> <file-name2>

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2.2.2 Abbreviations for and alternate forms of file names.

If you wish to omit <device> or <directory> – or rearrange their order – that's OK. DDT recognizes the device because it ends with a ":" and the directory because it ends with a ";". <File-name1> and <file-name2> must be separated by a space.

Example: The disk file on directory "JOE" with File-name1="MY" and File-name2="FILE" would look like:

                     DSK: JOE; MY FILE

Spaces may be included between any of the four items. They are necessary at the end of file-name1 and the beginning of file-name2, of course. Other valid ways of naming the same file are:

             DSK: JOE; MY FILE
             JOE; DSK: MY FILE
             DSK:JOE;MY FILE
             DSK:MY FILE JOE;
             MY JOE; FILE DSK:

and probably anything else that is similar – except, of course, that file-name2 may not precede file-name1.

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2.2.3 Special file-naming conventions.

There are a few special file-naming conventions on ITS. Some are just traditions; but some are specially recognized by the operating system, and interesting things are done with them.

Next: , Up: Convention The “>” convention.

There is one other important feature, or convention, for file names on this system. It is called the greater-than convention. This node will deal with that convention.

When the operating system sees the symbol ">" as a second file name in a file specification, it will not think you mean a file whose second file name is that character. This is a special convention which is very useful in creating numbered file names.

Why would anyone want a numbered file name? Well, let's suppose you are working on a program that involves considerable debugging. It is likely that you will want to create the program, test it, correct the file, and re-test. The most convenient way to do this on ITS is to create a file originally with a first file name the same as the name of the program, and a second file name which is a number.

So, let's say you've created a file called "MYPROG 1", and you discover it has a bug. What you would like to do is read it back into your editor (see other documentation on editors) and make corrections, writing the new revision out to "MYPROG 2". That way you can keep track of which is the newest revision, because it has the highest revision number.

To do this efficiently, there is the 'greater-than' convention. It says that if you try to read in (or print, or open for input in some other way) a file named "something >", what you really mean is to read in the file whose second name is the highest-numbered file with that first file name. And when you write out a file named "something >" – you NEVER want to clobber an existing file, so it will have a second file name one higher than any existing second file name for that group of files.

You can then go and delete the old revisions of the file by naming them explicitly.

Note that if you DELETE the ">" file, you delete the largest-numbered file in existence.

Previous: Greater-Than, Up: Convention Unusual first and second file names.

DDT treats files specially that have a first file name of TS. When a user types


DDT will look for a file named "TS <job-name>" in the directories in the user's search rules. If DDT finds such a file, the file is expected to be in a runnable binary format.

Traditionally, many second file names of files have been treated specially. The following is a list of some of those file names.

COMPRS This is a TECO compressed library. :EJ This is a TECO compiled library. (Note that ':' is special to file naming and usually means the end of a device field. To type in a file name with a ":" in it, you must type a ^Q (control-Q) immediately before the colon. Example: "DSK:FOO;BAR :EJ"

OUTPUT This is a temporary file output by a program. Such files should be renamed to something more useful when the program is finished with them. The GFR (Grim File Reaper) has been known to delete files with this name without asking.

@XGP This is a temporary file created by the ":@" command. The @ program normally queues this file for output on the XGP, and later deletes this file automatically. XGP This is a file created by some text-justifying program (for example, TJ6) for output on the XGP. Such files are also usually considered temporary. PRESS This is a file, also temporary, created for output on the Dover printer.

LAP This is a file containing a lisp-assembly program (compiled, not assembled). FASL This is a file containing a fast-loading lisp binary program (compiled and assembled).

(INIT) In the past, initialization files had funny first file names and '(INIT)' as a second file name. This convention has been flushed, in favor of a first file name the same as the user's login name and a second file name the same as the program name.

Thus, the following old file names now convert into the new file names as shown:

.DDT. (INIT) => <uname> LOGIN .DDT_ (INIT) => <uname> LOGOUT .EMACS (INIT) => <uname> EMACS .TECO. (INIT) => <uname> TECO .LISP. (INIT) => <uname> LISP MACSYM (INIT) => <uname> MACSYM

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2.3 How to manipulate files with DDT.

This node describes the DDT commands for manipulating files (for example, :PRINT, :COPY, :MOVE, :RENAME, etc.).

To print a file (don't use the term LIST - that's for directories) means to see its contents on the terminal you are typing on.

:PRINT <file specification>

will print a file. For example, to print out the documentation on DDT, you would do:


Remember, the ">" asks for the highest-numbered revision (which will be the latest documentation).

Other useful things to do with files are:

:RENAME <file-spec1>,<file-spec2> This will change the name of <file-spec1> to <file-spec2> – providing they are both on the same directory.

:COPY <file-spec1>,<file-spec2> This will copy a file named <file-spec1> anywhere, including between directories, to the location specified by <file-spec2>. Be careful that you have no existing <file-spec2>, because it will be destroyed by this operation.

:MOVE <file-spec1>,<file-spec2> This is just like :COPY but deletes <file-spec1> if the copying to <file-spec2> is successful.

:DELETE <file-specification> This makes <file-specification> go away. Be careful with this! Type the whole file specification. Don't leave any of the pieces out. The file specified by default (if you just type :DELETE followed by a carriage return) is the last file you referred to with DDT! There is no protection on files around here to keep them from being deleted. Users are expected to be sensible enough not to delete files that aren't their own (unless they have the owner's consent, of course).

A full list of all DDT commands can be gotten by typing ":?" at DDT.

While we're on the subject of printing, deleting, etc., it is well to mention that most of these commands have control-character abbreviations to aid in typing speed. ":PRINT" can be abbreviated as "^R" (Control-R). Thus you can do


to print DDT documentation if you don't like typing all of


With such power comes danger. ^O (control-O) deletes files. If you are a TENEX hacker, DON'T use ^O thinking it means to stop output!! It doesn't – it deletes files! (^S stops output.) ^O followed by a carriage return will delete the last file you printed or copied or otherwise referred to with DDT.

The :? commands will list these abbreviations (if there are any; :MOVE doesn't have one) in brackets at the end of the description. For example, the entry for :COPY is

:COPY <old file>,<new file> copy file, preserving date & FN2 [◊ ^R]

The abbreviation is "◊ ^R". One thing that should be mentioned: When you see a "$", it is probably NOT a dollar-sign, but an escape, so what you should type is <escape><control-R>

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3 How to create and manipulate jobs with DDT.

When you log in you are initially typing at DDT. DDT is your top-level job. Its primary responsibility is to help you in your use of other jobs. Things DDT can do fall into two categories: (1) DDT commands and (2) jobs.

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3.1 What are DDT commands; why are they useful?

This node will describe what DDT commands there are, and what you can do with them.

DDT itself is a job (DDT's formal name for a program), and it takes up a job slot in the system. The system has a fixed number of job slots (95 for MC, which has a large amount of real memory, fewer for the other ITS sites). Most DDT commands do not take up job slots (except those which are specific requests for creation of a job) – instead, you may think of them as subroutines in the DDT job. A full list of all DDT commands can be gotten by doing ":?" – any command that you do from DDT which is not on the list you get with ":?" is not a DDT command but a job. (See next section: Programs.) DDT commands include some file manipulation commands (see section on file manipulation), system status, and many debugging commands.

All commands and job names are only six characters or fewer. You may type more characters, but only the first six will be used in the creation of a job name.

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3.2 What is a user program? How does it differ from a DDT command?

Your process is structured in the form of a tree with its root at the top. DDT is at the top and it may create lower nodes which may (on rare occasions) create lower nodes below them. When you run a DDT command, you stay in the node of the tree called HACTRN (the job name of your DDT). If you create two jobs (called FOO and BAR, for instance), your tree would look like this:

                            /      \
                         FOO        BAR

DDT itself is a job. Other jobs can be created by DDT. DDT is responsible for keeping track of which job you are in and moving you from job to job. Jobs are created by typing a ":" followed by a job name followed by a carriage return. (Note, many DDT commands use the same syntax – there are no jobs with the same name as DDT commands, so this isn't a problem.) For example, typing ":NAME" followed by a carriage return will start a job that will tell you the names of all the people logged into the system.

To return from a job to DDT temporarily, you can type ^Z (control-Z), which will harmlessly leave the job in a manner that it can be re-entered later. For example, if you are in a Macsyma and receive a message from another user to which you would like to reply, you can type control-Z, which will return you to DDT temporarily; then send your reply; then re-enter your Macsyma with ":CONTINUE" (see below) without having harmed what you were doing in it.

The following DDT commands may be useful for manipulating jobs:

:LISTJ - lists all of your jobs. The current job (if you have any jobs) will have a "*" beside it.

:CONTIN - continues running the current job, as if you had never left it.

:JOB - rotates the job tree. (It selects the next job in the tree as the current job. It may be useful to think of your jobs as being in a circle, upon which :JOB will move you from point to point.) Typing this when you have no jobs will give the response: "JOB?". This is a DDT error message equivalent to "Are you implying that you think you have a job?" It isn't asking for an answer – all DDT errors just seem to end in a "?".

:KILL - You will see many jobs do this on their own when they are done doing their thing (:NAME for instance). If you have control-Z'd out of a job and are done with it, you should do ":KILL" to free up the job slot it consumes.

:MASSAC - (short for :MASSACRE, but, due to the rule about 6 characters, :MASSACHUSETTS will also work if you're fond of extra typing) will kill all of your jobs in one fell swoop. (It won't affect detached trees, however – there's an entry later on about how to deal with detached trees if you've run across one and wondered what to do.)

Some DDT commands and jobs require additional information in order to do their thing. Some may allow additional info but not require it. This additional is called JCL (Job Control Language), and, unlike IBM JCL, ITS JCL is simple and does not require years of study to master – you just put the info the job needs on the line after the job name and before the carriage return.

For example, the ":JOB" command – that we mentioned will rotate your tree to the next job – may be given JCL to get it to do something different. If you do something like


you will reselect the job FOO, no matter where it is in your job tree. (Note: If no such job FOO exists in this case, a slot will be allocated for it. The job will have no program in it and will be essentially useless to you. If this happens, you can make the job go away with ":KILL".)

Also note that there is a DDT command called :JCL that allows you to specify JCL for a job. Do NOT use it for the time being. Using it correctly requires more advanced knowledge of DDT than you probably have right now if you are reading this. It will likely have an un-noticed effect on your jobs, but it may produce VERY odd results as well under certain circumstances.

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3.3 Useful control characters.

This node will discuss some of the useful control characters which are recognized by DDT, and how to make use of them.

Control characters are produced by holding the control-key on your terminal and typing the character. (It's like a different flavor of Shift key.) Control characters are printed usually as up-arrow ("^") followed by the character. Don't type the "^" – just hold down "control" and type the character following the "^".

<Altmode>, ◊, or ^[ Many programs, including DDT, treat this character specially. Note that there is a character $ (dollar sign) on your terminal, and it probably echoes the same as ◊ (Altmode). To get <Altmode>, type the key marked <ESC> or <ALT> or <SEL> on your terminal. It will echo as a ◊. Very few programs mean $ (dollar sign) when they echo the dollarsign - most mean <Alt>. But be aware that there is a difference, so you're not completely lost.

If you're using a very fancy TV keyboard, there may be two keys - one marked ESC and one marked ALT. Use ONLY the key marked ALT in that case.

^D This flushes any partial input to DDT.

^G This is DDT's quit character. If you are at DDT level, this will echo "QUIT?" (which doesn't mean it wants an answer). You are then ready to type a new command to DDT.

If you are using another program, ^G will be handled by the program. Most programs will handle ^G by quitting and going back to the main command reader.

^L This clears the screen. If there are pending, unprocessed characters (that is, you're in the middle of typing a command) it will redisplay those characters.

^S This flushes output at DDT level. Once a given output is flushed, you must type the command again and restart the output all over. There is no way to resume a flushed output from the point it was stopped. This command is not meant to stop a command from working. It just stops its output.

^Z This causes a program interrupt asking a job to return to its superior. If you are running a program, EMACS for example, and wish to exit for a moment to do something else, type ^Z. This will bring you back to DDT, suspending your EMACS job. (For more info on job selection and re-entering jobs, see the section on job manipulation.)

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3.4 How to get back a detached tree.

If you have a detached (job) tree, you will be told so when you log in. Typing <Space> to the message "–Attach your detached tree–" will work.

If you miss your chance, type the following magic incantation immediately after you have logged in (if you want the old tree back):

                     :REATTACH <your-name>

where <your-name> gets replaced by the login name you use. For example, if you log in as JSMITH, you do

                     :REATTACH JSMITH

and your old tree will be magically reowned. If this doesn't work, or you are unsure, feel free to do :LUSER, which will request a system wizard to help you.

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4 How to find and communicate with other users.

ITS is a time-sharing system. There are many other users who use the computer, and it can be to everyone's advantage if you are able to know who is logged in and how to communicate with them when you need help (as well has how to give help to others when they need it). This node attempts to deal with some of these issues.

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4.1 How to find out who's logged in.

There are many system programs for finding out who is using or has used this computer, and whether they are currently logged in. This node gives a brief description of what each does.

The following commands will give info about who's on the system (in increasing levels of verbosity):

:U or :USERS lists the user names only of all users logged in.

:W or :WHO lists the user names and TTY (terminal) numbers of all logged in.

:WHOJ lists the user names, TTY numbers, and job names of all logged in.

:NAME, :FINGER, :F lists the user names, affiliations, real names, job names, idle time (time since the user typed on the terminal) if any, TTY number, and TTY location for all logged in.

:WHOIS lists the same as :NAME plus an incredible array of extra stuff like home addresses, nicknames, remarks to INQUIR, etc. for all logged in.

Some of the commands do different things with something on the same line as the command (JCL line). Examples:

:WHOIS <name> lists personal description of <name> regardless of whether he or she is logged in.

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4.2 Communicating with other users using MAIL and SEND.

There are two basic forms of message sending, SEND and MAIL. This node talks about how the :SEND and :MAIL commands are used, and the cases in which it is desirable to use one over the other.

SEND is something that you use to send a message to a person who is currently logged in and whom you want to get the message right away. The usage is:

:SEND <name> <message> ^C

Note that since the message is terminated with a control-C, it may extend over more than one line. So something like:

:SEND JOHN Hi. How are you. I have a problem. I don't know how to use :SEND ^C

is perfectly acceptable.

When you type the control-C at the end of the send, JOHN will immediately receive the message on his terminal. It will look like:

[Message from <Yourname> at <Machine> <Time>] Hi. How are you. I have a problem. I don't know how to use :SEND

He can then respond to you with a message explaining that you are bothering him with untrue complaints since you had to know about :SEND to send the message. Anything a user receives that is sent via :SEND will be deleted when the user logs out. Until then, it is accessible by the :PRSEND command...

:PRSEND or :PRSEND <name>

For more info on how to use :SEND try typing ":SEND ?" immediately followed by a carriage return.

MAIL is the way to send mail to another user that you don't expect to be read now or that you want to be saveable. MAIL will not be deleted until it is explicitly read by the recipient(s). If they are logged in, DDT will print a message on their terminal(s) telling them they have mail, which they may choose to look at or not, depending on how busy they are. If you try :SEND <name> and it immediately types "(Mail)", it means the user is not logged in or not accepting messages (perhaps they are trying to get a nice printout), and your SEND will go as mail.

To print your mail, use :PRMAIL. The usage is:

:PRMAIL or :PRMAIL <name>

For more detailed information on MAIL, see *Note Mail:(Mail).

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4.3 How to enter items for others to read in :MSGS

Announcements are messages that everyone will read with the :MSGS command.

There are two kinds of announcements: System Messages and Bulletin-Board Messages. (See *Note Announcements: (SYSMSG). You can do that by typing "F" for footnote, followed by enough letters of the word "Announcements" to distinguish it from the other footnotes in this node. Then, type "L" to come back here to continue with your introduction.)

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4.4 How to tell if the system is 'heavily loaded'

This node describes how to recognize a heavily loaded system, and the meaning of the term "fair share," and what net ports are.

It is hard to define precisely what is meant by a "loaded" system. There are several different kinds of system resources which are needed from time to time, and, if any of them are exhausted, the system may be said to be heavily loaded.

If you are connected to an ITS machine from the ARPAnet (or another ITS machine), then you are using a net connection called a "port." If you are using the CRTSTY program for a terminal type which ITS does not support directly (VT100, ADM3A, etc.), you are using two net ports. There are a limited number of net ports.

Additionally, your CRTSTY is using a job slot. A job slot is just what it sounds like. Your HACTRN (the monitor program you are running when you aren't doing anything else) and this INFO program are examples of jobs. Like the number of net ports, the number of job slots is limited, and it varies from site to site.

If you want to find out about system status, you can call the LOADP program by typing


If you type ^Z and :LOADP now, you'll see something which looks like this:

          12 users idle less than 1 minute.
          5 idle 1 to 5 minutes.
          3 idle 5 to 10 minutes.
          4 free net ports.
          3 free job slots.
          :KILL INFO◊ J

Type "◊ P" (or ":CONTIN ", since they do the same thing) to return to INFO.

The load described in the above example is too much for tourist usage on any machine but MC.

SSTATUS is a DDT command which prints out some other system load information. The following guidelines may be helpful in interpreting the information that :SSTATUS will give you:

[1] Fair share below 40% – Fair share changes a lot from moment to moment, even with light load, but, if it is consistently below 40% or (Heaven forbid!) 10%, then the system is pretty loaded.

[2] Over 18 users on MC, 15 on AI, 7 on ML and DM. No matter what else is happening, things start to slow down and job slots start to get scarce when the number of users starts to climb.

[3] Fewer than 10 job slots.

Any time you get a message from a lab member (or the SYSTEM OVERSEER or GUNNER) asking that you log out, you should do so immediately. Even if the above guidlines indicate that you should be able to stay logged in, other factors which are not mentioned here may be in play.

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5 Where to get written documentation.

This node contains documentation about where to find written documentation on and offline.

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5.1 How to order manuals.

Available from the MIT Laboratory for Computer Science publications office:

* MacLisp Manuals ("Saturday Evening" Edition, 1983) are $8.90, postage included.

* The Macsyma Manual (9th edition, maybe out of print) costs $5.00. A 10th edition, published in 1982, is available as a three-volume set. It costs more; we should look up the price and insert it here sometime.

* There are two manuals for MDL:

"The MDL Programming Language" ($4.00) describes the language itself.

"The MDL Programming Environment" ($3.50) describes MDL programs that can raise a MDL programmer from "basic survival" to "comfortable living".

* A list of other LCS publications is free. These include Technical Reports, Technical Memoranda, and Progress Reports.

The address of the MIT Lab for Computer Science publications office is

Publications Distribution MIT Laboratory for Computer Science 545 Technology Square, room 112 Cambridge, MA 02139

Make all checks payable to "MIT Laboratory for Computer Science."

Please add $1.00 per order for postage and handling unless otherwise noted.

—— —— ——

Available from the publications office of the MIT A.I. Laboratory:

* The Lisp Machine Manual

* A list of AI Lab publications is free. These include Technical Reports, Memos, Working Papers, Books in Print, etc.

The address of the MIT A.I. Lab publications office is

Publications MIT Artificial Intelligence Laboratory 545 Technology Square, room 908 Cambridge, MA 02139

Make all checks payable to "MIT Artificial Intelligence Laboratory."

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5.2 On-line (non-interactive) help files.

This node contains nodes which are the long documentation files for some of the major user programs available. These files are on-line with more or less complete documentation about certain major aspects of the system. (These files are ones which are not currently structured for the INFO program.)

Note: ITS TECO is not the same as DEC's version. Read the documentation before using it (especially for any commands starting with "F" or "E", which are all different on ITS).

Other files on the .INFO. directory may also be useful. Do ":LISTF .INFO." for a list of the files.

There is also an INFO directory, which contains files in a format used by the :INFO program. Don't bother to print these; run :INFO instead, since it knows how to read those files in a nicer way!

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5.2.1 MDL Documentation

The MUDMAN directory is the place to look for documentation on MDL. There are two separate "manuals" on this directory. The larger is an on-line copy of the printed "The MDL Programming Language". It is contained in the file DM:MUDMAN;REFERENCE MANUAL. Its separate chapters are in the ARChive file DM:MUDMAN;ARC MANUAL. You can "step through" it a chapter at a time by


and incrementing the chapter number until you run out of them.

The :MUD program on DM may be useful in obtaining documentation on individual primitives (SUBRs or FSUBRs) from a shorter on-line reference manual (MUDMAN;MUDDLE ORDER). Sample usage:

:MUD This command will list all of the MDL SUBRs and FSUBRs and a short (one-line) description of what they do.

:MUD MAPF This command will describe the MDL SUBR MAPF.

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5.3 Programs that give on-line help.

This node deals with programs running on ITS that give helpful information or documentation about programs not described through INFO.

The following other methods of obtaining info on this machine's programs are available (in addition to the INFO which you are now running):

:? This will give a full list of DDT commands.

:LUSER This will send a message to any system people now logged in, saying that you are in trouble or greatly confused and need help. It will send to a large number of people if all the helpers are logged in, so try not to rely on it always, but these people can be very helpful if you are really lost.

:SEND (fully described in the section on SEND/MAIL commands in this file) can be used of course, too. If you're wondering whom to ask, do :NAME and pick a system native out of the logged-in users. Natives to MC will have an "M" by their names, natives to ML a "P" or "Z", natives to AI an "A", and natives to DM a "D". They can probably either answer your question or suggest someone else who can help.

>>> How NEVER to request info:

:SHOUT This is a command to send a message to all users. It works like :SEND but doesn't need a name of a person to send to, since it sends to all logged-in users. This is NOT for casual use, since it interrupts everyone. If you are thinking of using this to find out the answer to a question, don't. Use :LUSER, which will bother only people who have volunteered to help out in such situations.

This command also DOES NOT put something in the system messages that you see when you log in. The way to send a system message is documented elsewhere in this file.

Next: , Previous: Helpers, Up: Documentation

5.4 Programs that teach things.

There are a few programs available, which will actually attempt to teach you how to use themselves: EMACS (a text editor) and MACSYMA (a symbolic algebra system (running on MC only)). This node will tell you about how to start them up in teaching mode.

:TEACHE This program works only if you are on a display terminal (CRT which can display on other than just the bottom line of the screen) and ITS knows your terminal type (via :TCTYP). This program will teach the EMACS editor – by far the fanciest and most powerful of the editors available.

On the MC machine (ARPAnet host 236 decimal), the following are also available:

:TEACHM This program goes through a basic primer for the Macsyma language, interactively. Macsyma doesn't run on ITS machines other than MC, so neither does this program.

:TEACH;LISP This program offers an interactive introduction to the Maclisp language. It is also available at MIT-OZ as <KMP.TEACH>TEACH-LISP.

Previous: Teachers, Up: Documentation

5.5 How to order other documentation (besides manuals).

This node contains information about ordering Macsyma documentation via US Mail.

Documentation, which accompanies orders for Macsyma manuals automatically, but which may be ordered separately if needed, includes:

"An Introduction To ITS for the Macsyma User" – $1.00 (available on-line as .INFO.;ITS PRIMER)

"The Macsyma Primer" – free (available on-line and interactively through :TEACHM)

If you need a photo-copy of these, you can send mail to MATHLAB-SECRETARY (that is, :MAIL MATHLAB-SECRETARY ...) asking for info. If you don't know how to send mail, there are directions elsewhere in this piece of documentation.

If you are not planning to use Macsyma regularly, don't ask for the documentation unless you are seriously interested in it and cannot obtain it another way. Remember that you are asking a favor of the secretary, so don't irritate her with messages like "Send one manual immediately to ..." – introduce yourself and explain that you would appreciate it, etc., and you will have a much better chance of being taken seriously.