Almathera Ten Pack 3: CDPD 3/Almathera Ten on Ten - Disc 3: CDPD3.iso/ab20/ab20_archive/utilities/emulators/apple2emul.lzh/Samp.disk/MUSYS DOCUMENTATION.txt

Text File | 1991-04-18 | 10KB | 399 lines

                              MUSYS DOCUMENTATION



                         Musys, written by Rich Skrenta

                         Quick summary and instructions




           I wrote Musys to experiment with multitasking on the Apple.

        It was never intended to be especially useful, but rather to

        look, from the surface, something like a "big system."  Please

        keep this in mind while reading this.  I am writing this because

        a few people have expressed interest in Musys, and some of its

        nicest features need some explanation.



           First, here are some important terms which I used and what

        they mean in the Musys evironment:



           STATUS     Level or importance of job.  1 is an operator, 2 a
                      wheel, below 10 is privileged, below 50 is logged
                      in, and above 60 is not logged in.

           PRIORITY   How often a job executes.  In other words, how
                      fast it goes.  1 is fastest, 10 is very slow, 0 is
                      slowest.

           RUNSTATUS  Condition of job:

                      128  is a safe job.  Left alone by system.
                      64   is a batch job.  Killed when there is no more
                           input or output.
                      32   is not logged in.  Killed after 2 minutes.
                      16   is being logged out.  Killed after output
                           buffer is empty (logout message sent) or 2
                           minutes.

           USERID     Up to six letters describing user of a job.
















                              MUSYS DOCUMENTATION




           First of all, you might want to get into the system and see

        what I am talking about.  Brunning MULOAD puts Musys in the

        language card and gives you 18 jobs max.  Brunning MUSYS gives

        you 8 jobs max.


           After you Brun in, nothing will appear to happen except a

        short line will appear.  That is the cursor.  You can hit return

        or ctrl-c to start.  It will print a short login message, saying

        what job you are, and give you the "@" prompt. (you can change

        it).  This is the exec level, from which most commands are

        typed.


           Now, a word about jobs.  Musys has real jobs.  It doesn't

        just make it look like they're there, they really are.  8 pages

        of memory are allocated for each job, 5 of which are used (the

        other 3 are wasted, but it doesn't matter).  Each job has an

        input device, an input buffer, an output device, and an output

        buffer.  Every MUSYS cycle (once through the big loop) Musys

        will check the input device for data.  If there is some, it

        pushes it onto the input buffer (all buffers are fifo, by the

        way).  It also looks for something in the out buffer, and sends

        it to the output device, if it can.



           Now, for my device list.  These are the devices available:

           1     SYSTEM CONSOLE
                      Fancy name for combination of keyboard & screen.

           2     PRINTER (slot 1)
           3     D.C. HAYES MICROMODEM (slot 2)
          ...









                              MUSYS DOCUMENTATION


          ...
          (now, the hard part)

           16-31   PSEUDO-TERMINALS

                       Well, almost.  Devices 16-31 are 256 byte fifo

                       buffers which can be used just like devices.

                       Stuff output to them goes in, and input comes

                       out.  They are very useful.



           About the parser:  I wrote a nice parser for Musys.  The

        first feature is that you don't have to type the whole command,

        only the first unique letters.  For example, there are the

        commands TEST and TIME.  If you typed T return, you get an

        ambiguous command error.  But you can type TE to start tester,

        or TI to read or set the time.  Simple, huh?  By the way, you

        can type the whole command, if you want.


           Second feature:  the ? option.

        Typing a ? in gives you the options for a particular level.  For

        example, typing just ? return gives you all the exec commands.

        Typing DO ? return gives you the options for the DO command.

        Got it?


           Oh, one more thing.  Commands and options can be seperated by

        any of the following:

          (space) "(),./:;=<>

        so, any of the following would do the same thing.

        DATE 6/6/67
        DAT   "06/06/67"
        DATE      6,6,   67
        DAT   (6..;6;;=67)>










                              MUSYS DOCUMENTATION


        Isn't that nice?
           A word about control characters.  Musys recognizes the

        following controls:



           C          two control c's bring you back to the exec
                      immediately, one at the next input.

           H          delete
           L          clear screen & retype line
           O          suspend/restore output
           Q          undo a ctrl-s
           R          retype line
           S          put job on hold until ctrl-c or ctrl-q
           T          print out job information



           Finally, the commands.  I wrote a lot of commands for Musys.

        Most of them, however, just do things to the system itself.  No

        practical application, you see.



        Anyway, the Most Important Command:

           SYSTAT     Tells you all about all of the jobs currently

        running.  Gives the devices (input,output), the userid, name of

        the program it is currently in, etc.


        Next command:

           DO         /OUTPUT:
                      /PRIORITY:
                      /STATUS:

        The DO command is for batch jobs.  When you type DO return, it

        will open a pseudo-terminal and tell you.  Then you can type in

        commands to the # prompt, and they will to into the fifo device.

        When you are satisfied, hit ctrl-z, and if there are no

        problems, Musys will make a job whose INPUT device is the pseudo

        terminal you just put commands into.









                              MUSYS DOCUMENTATION



        POSSIBLE ERRORS:   NO FREE PSEUDO-TERMINALS
                           NO FREE JOB SLOTS
                           BUFFER OVERFLOW

        The output option allows you to send the job output somewhere

        (normally, it goes to device 0, the null device).  Example:

        DO O 2

        would send the do jobs output to the printer.


           Remember, some commands require a special status, such as

        operator, to do.  I will briefly explain a few more commands.

        The rest should be self explanatory.


        KTIME is the clock constant.  Fiddling with this make make the

              time a bit more accurate.

        HALT  puts you in the monitor to make changes.  You can restart,

              with all of your jobs intact, by typing ctrl-y return.

        PICKUP  picks up the modem.  Someone should then be able to log

              in on the modem with a few ctrl-c's, but you may have to

              type pickup a few times at first.

        HANGUP  hangs up the modem

        TIME   read or set time

        DATE   read or set date

        DAYTIME  read time and date.

        LOGIN (userid)  logs in a wheel, priority 1 with the indicated

        usreid.

        TERMINAL   HALF        half duplex
                   FULL        full duplex
                   OPERATOR    secret passwords make job an operator
                               job. (oh well, the pass is "stick")












                              MUSYS DOCUMENTATION




           Why all the protection junk, you ask?  Well, about the most

        use I've found for my program is "terminal wars".  In this game,

        formerly playable only on big systems at a great risk, you try

        to become an operator and blow your opponent's jobs away.  Well,

        now the lowly Apple owner can have fun, too and blow away all

        the jobs he wants to.


           And just to make it sneakier, there is a strange trapdoor in

        the system.  If you type ctrl-shift-n, you instantly become job

        3, an operator, and are completely safe from attacks.  People on

        the modem cant do this.



           Not very useful, but it can be a lot of fun.  The first 3

        days, at least.  GOOD LUCK!!



        Special thanks to Tom Markson, the only other person who really

        knows what it can do.