LIFE
                              --------------------------

          This program implements the Game of Life, a diversion, by John
          Conway. It produces a new generation every 3.5 seconds.

          The rules set forth dictate that every empty cell surrounded by
          exactly 3 live neighbors gives birth. Every living cell
          surrounded by either 2 or 3 live neighbors remains alive. Any
          living cell surrounded by 4 or 5 live neighbors dies out from
          over crowding and dies from isolation if surrounded by 1 or no
          living neighbors.

          Interesting patterns emerge over generations. I find this the
          interesting feature of this diversion. An article in the
          December, 1978 issue of BYTE magazine describes some of these
          patterns. (Unfortunately, I no longer have access to that
          article. I would appreciate anyone who could electronic mail me
          the patterns mentioned in the article.)

          Some patterns are static such as in figure 1. Other patterns are
          cyclic patterns which go through a determined set of
          tranformations and return (figure 2). A few cyclic patterns,
          called gliders, move as they go through their transformations. I
          list the simplist one in figure 3. Finally, other cyclic patterns
          called generators create other patterns. After a set number of
          transformations they remain the same, but have produced some
          others along the way.

                                       x
                                      x x      xx
                                      x x      xx
                                       x

                                          Figure 1
                                      Static Patterns



                                          xxx
                                         x   x
                                         x   x       xxx
                                         x   x
                                          xxx

                                          Figure 2
                                    Oscillating Patterns



                                          x
                                           x
                                         xxx

                                       Figure 3
                                     Simple Glider

          This program will accept graphic screens created by the Palette
          program found in Library 5. The area used by life run from dot
          column 1-128 and dot rows 1-64. The center of the life grid lies
          at x=64, y=32.

          The program begins with a random 20 by 24 dot pattern.

          The following functions are provided:

                  F8      Return to menu.
                  F7      Load a screen.
                  F6      Create a random pattern.
                  F5      Save a screen.
                  F4      Reload the previous random screen.
                  PRINT   Print the screen. (DMP-400 dot matrix printer.)

          Any other key causes the program to wait until the SPACE key is
          pressed.

          To use this program download LIFEHX.DO and use James Yi's
          HXFER.100 in library 7 to change to machine code.

          This program requires approximately 11 K for buffers. Himem
          should be set (with the BASIC CLEAR command) at 10115 bytes below
          the beginning address of the program. For the default loading,
          this is 51132. The program itself occupies about 1705 bytes and
          resides at the high end of memory.

          Another screen print program may be inserted at 62711 to high
          memory on my machine, 62960. The address of this printer routine
          should be placed in a jump table at the beginning address + 7.
          (Low byte at beginning address + 7 and high byte at beginning
          address + 8.) The program jumps to 62711 when beginning address +
          6 is called. Prior to calling the printing routine, the screen is
          transfered to a 1920 byte buffer. The printing routine included
          then uses this buffer to print the image.

          Note, relocating the life program will cause compatibility
          problems with Palette. The LOAD and SAVE commands produce a
          Binary file which will load at 54254 where Palette expects to
          find it. Relocating the program will move the loading location of
          the file. To relocate the program retrieve the source file and
          use James Yi's ADSM.100 program to reassemble it. (Be careful!
          The various buffers have been arranged around the PALETTE 1920
          buffer at 54254.)

          Thanks to Robert D. Covington and his Model 100 System Map. I
          also learned much studying James Yi's HXFER.100 source code.

          John Conway's game of life.
                          SCIENTIFIC AMERICAN October 1970
                          BYTE September 1975
                          BYTE December 1978

          For those who have a dot matrix printer similar to my DMP-400 I
          include the command codes so you can poke in the proper codes for
          your machine. I have left some room for expansion. Note the code
          string should end with $FF, not the more usual $00.

          TWIXT   DB 30           ;GRAPHICS OFF - Called between each line
                  DB 27,28,$D     ;LINEFEED
                  DB      18      ;GRAPHICS MODE
                  DB      27,16   ;POSITION
                  DB      0,20    ;AT COL 20
                  DB      $FF     ;DONE
                  DB      $FF,$FF,$FF ;extra


          PSTRNG  DB      27,20   ;CONDENSED - Initial command sent to
          printer
                  DB      18      ;GRAPHICS MODE
                  DB      27,16   ;POSITION
                  DB      0,20    ;AT COL 20
                  DB      $FF     ;DONE
                  DB      $FF,$FF,$FF
                  DB      $FF     ;extra

          GOFF    DB      30,$ff,$ff ;at conclusion of printing.


          Ken Jackson
          71316,01321

          1023 West Sixth St
          Duluth, MN  55806