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        º  Lesson 1 Part 3.0  F-PC 3.5 Tutorial by Jack Brown  º
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Glad to see you back.  Start you Forth engines, we are about to begin
again.  Here is a summary of the ideas of the last message and some new
words that we are going to look at.

                 ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
                 ³  Elementary Word Definitions.  ³
                 ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ

: {name}    word1  word2 . . . wordn  ;

:       Begin a word definition.

;       End a word definition.

{name}  This is the name of the new word definition.

word1 word2 ...  Forth words in definition.

Example:

: FIRST   CR  ." This is my first FORTH program. "  ;

."  {string}"   Compiles string,  when word is executed string
                is displayed on the display or console device.

CR              Start a new line. ( carriage return/line feed )

               ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
               ³   Some Important System Words.  ³
               ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ

WORDS         List all words in the FORTH dictionary.

EMPTY         Remove all new words added since entering FORTH

FORGET {name} Remove {name} and all words defined since {name}
              from the FORTH dictionary.

First try  WORDS <enter>    <---- quickly press  ESC before

your screen fills up!  You can also use the space bar to temporarily
halt the words listing.  You should see the first name list for you
favorite people phone list if you saved the system as instructed in the
last message.

Let's  suppose that you don't like these people any more and that you
want to remove them from the system.  To do this you can just type:

EMPTY <enter>  <---- do this now.

Now try getting my phone number by typing  JACK as before.
Did you get the phone number ??  Type:

WORDS <enter>   <---  Stop it quickly !!

Do you see the phone list ???   Your phone list should be gone.  You
have Forth back to its original state. Now exit the Forth system. Type:

BYE <enter>

And start it up again with   F at the DOS prompt. Type:

WORDS <enter>

and you should see the phone list again.  This is because we did not
re-save the forth system using the FSAVE command.  We will do this
shortly but first lets suppose you don't want to forget the entire phone
list. Suppose you only want to forget the last word (person) that you
added.  To do this type

FORGET  {name}  <enter>

Do this now and type WORDS to see if  {name} has been forgotten. You
could also type {name} to see if Forth can still find the phone number.

Well let's get rid of the phone list once and for all!  We will have to
empty the system of all the words that we have added by typing  EMPTY
<enter>  again.  And then we will have to re-save the Forth system by
typing

FSAVE F <enter>

Do this now and then exit Forth by typing BYE. Now start Forth again and
see if your phone list has been forgotten for good.  You can find out by
trying to get back one of the phone numbers or by using WORDS to look
for your favorite people.  You should find that they no longer exist!

ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³  Please move to Lesson 1 Part 4.0  ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ