COMMENT ⊗   VALID 00004 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	                             MEMORANDUM
C00006 00003	             Stanford Artificial Intelligence Laboratory
C00011 00004	                       Maximum Service Levels
C00014 ENDMK
C⊗;
                             MEMORANDUM

                                                         17 June 1970
To:      Artificial Intelligence Laboratory Users

From:    L. Earnest

Subject: Another Computer Reservation Procedure

The timesharing monitor has now been modified so that the  amount  of
processing  you  get  decreases linearly with your core size. The new
rules are given in the attachment.

The timesharing scheduler gives different priorities to each of three
user classes:
    1)  interactive users
    2)  reserved users
    3)  scavengers
The first goal of the scheduler is to provide good service to  anyone
doing interactive work such as editing.  The System decides whether a
given job is currently interactive on the  basis  of  keyboard  input
activity.

You  get  to  be  a reserved user by reserving a service level on the
signup sheet and telling the scheduler about  it.   For  example,  to
request a service level of 20%, type
    .SL 20
Whenever you are running, the scheduler will then attempt to give you
a processing level (% of CPU time) given by
    PL = SL - C/5
where SL is the service level and C is your current core size (in K).
The system will not let more than a certain total service level to be
allocated in this way (currently 80%).

If  you are neither interactive nor reserved, you get some of what is
left, which may be pitifully little.  The system is supposedly rigged
so  that  reserved  users  always  get  service  at  least as good as
scavengers.   Note that if you are editing and execute a long-running
string  search,  the  system  may decide you are a scavenger and take
forever to finish.

To keep things honest, WHO now shows service  level  declarations  at
the  right  end  of  the job line.   Users are encouraged to publicly
denounce outlaws and urge them to reform.  In case  moral  persuasion
doesn't work, let me know and I will employ immoral persuasion.

WHO  will  shortly be modified to display the actual processing level
being provided to your program, so that you may have a more  concrete
basis  for  complaint.   Hopefully, the reservation system will be in
the computer before long.  As soon as the Data Disc displays  are  in
operation, displays will no longer be rationed.
             Stanford Artificial Intelligence Laboratory


Effective date:  22 June 1970

Each  authorized  user has an allowance of two kinds of money, called
"whams" and "bams".   Whams may be  used  only  to  purchase  display
terminal  time,  while  bams  are  good  only  for  CPU service.  The
allocations are as follows.
			Whams	  Bams
    Half time user	  4	   100
    Full time user	  8	   200
    Panic User		 16	   400
You are "half time" or "full time" in accordance with the portion  of
your time devoted to A.I. activities.  In an emergency situation, you
may be given a short term appointment as a Panic user.

Your "money" allocations are actually revolving funds in that if  you
reserve  machine time and use it, you may then re-use the reservation
money.  In effect, then, there is a limitation on how  much  you  can
reserve  at  a  given time.  There is no conversion between whams and
bams, nor can funds be transferred between persons.

The display costs W (whams/hour) vary with time of day  as  given  in
the  table below. The price P (bams/hour) of buying any given service
level SL (in percent) is
        P = SL*B*T
where B is the rate (bams/hour) given in the same table and T is  the
number of hours.
       Time           0000-0900   0900-1300   1300-1800   1800-2400
	                W & B	    W & B	W & B	    W & B
  Monday-Friday	          1	      2	          3	      2
  Sat., Sun., holidays    1	      1	          2           1
You  may reserve a display without a service level or vice versa, but
reservations may be made only for integral  hours  beginning  on  the
hour.   Other  peripheral  devices  may  be reserved only if you have
reserved a service level.  Service levels may be  purchased  only  in
multiples of 5%. The attached table gives maximum service levels that
can be purchased in any given time zone.

III display reservations may be made  for  a  particular  display  by
putting  a  parenthetical  digit (0-5) after your initials.  Initials
without a digit are interpreted as "don't care  which".  In  case  of
partial equipment failure, signups on the left side of the sheet have
priority.

All entries must be in pencil.  Entries in ink are void and should be
ignored.

You may purchase unreserved or unclaimed resources (see 5 minute rule
in SAILON-37) at any time if you have enough money.   If  someone  is
logged  in  on  a display that is reserved but unclaimed, however, he
has first priority to buy that hour.  You should enter your  initials
on the reservation sheet to record ownership.
                       Maximum Service Levels


To find the maximum service level that can be reserved during a given
period,  first  look  up  the  price  B (1, 2, or 3 bams/hour), given
above, then look down the corresponding column below to the number of
hours  you  wish to run.  The maximum service level you can afford is
given under your user  class.   For  example,  in  the  afternoon  (3
bams/hour),  a  fulltime user who plans to run 3 hours may purchase a
service level of 20%.

		Price B (bams/hour)          User Class
		  3      2      1        halftime  fulltime
		--------------------   --------------------
		              1 hr         80%       80%
		       1 hr   2            50        80
		1 hr          3            30        65
		--------------------   --------------------
		       2      4            25*       50
		              5            20        40
		2      3      6            15        30
  Duration	--------------------   --------------------
		              7            10        25
		       4      8            10        25*
		3      5      9-10         10        20
		--------------------   --------------------
		4      6      11-13         5        15
		5-6    7-10   14-20         5        10
		7-13   11-20  21-40         0         5


* Indicates the level that can be purchased with  concurrent  display
service.