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      º   Lesson 1 Part 5.0  F-PC 3.5 Tutorial by Jack Brown  º
      ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ

Welcome back.  In this lesson we will take a look at how to use F-PC's
built in editor.

Our first program will is going to display a checker board on the
display screen.  Instead of typing the program directly line by line as
we did with our simple databases we will type the program into a
separate text file using the EDitor.  The advantage is that it will be
easier to fix our mistakes, (won't have to retype the whole program) and
we will have a permanent copy of our final working program.

In F-PC the default extension for Forth source code files is SEQ.

Lets call the file that we will contain our checker board program
BOARD1.SEQ  where the 1 is for our first attempt (there may be many!).

Before we start the EDitor let's make sure that the current directory is
the work directory.  Type:

CD  C:\WORK <enter>  <----  or what ever you called your work directory.

If you wanted to keep your files on the A: drive instead you could just
type:

A: <enter>
CD  A:\WORK  <enter>   <---- if you have a WORK sub directory on A:

To start editing a new file called BOARD1.SEQ, Press <ESC> and select
the New File option and enter the file name BOARD1 when prompted to do
so.   You can begin editing a new file by pressing  <ALT> N and entering
the file name when prompted to do so.  Do this now and you should see
something like the display below.

ÉÍÍINSERT  Line=1  Column=0  Page#=1  Lines=2   Characters=2  ÍÍÍÍÍÍ»
º                                                                   º
º             ( this takes up the full screen!)                     º
º                                                                   º
ÈÍÍHELP=F1ÍÍÍÍÍÍÍÍÍÍÍFile = C:\WORK\board1.seq ÍÍÍÍÍMENU=ESCÍÍÍÍÍÍÍͼ

The graphics display here is no match for Zimmer's!

The editor is for the most part uses commands similar to the wordstar
editor, sidekick editor, and those included with the Borland Turbo
products.  Use the Help function key F1 to get HELP screen and choose
the SED-Help menu item for further help with the editor commands. Enter
the following program using the editor.

\ CHECKER BOARD PROGRAM
\ Version Number: 1
\ Date: September 18, 1988
\ Author:  <your name>

: BLACK ( -- )
        SPACE SPACE ;

: WHITE ( -- )
        177 EMIT 177 EMIT ;

: ROW1  ( -- )
      CR BLACK WHITE BLACK WHITE
         BLACK WHITE BLACK WHITE ;

: ROW2  ( -- )
       CR WHITE BLACK WHITE BLACK
          WHITE BLACK WHITE BLACK ;

: BOARD ( -- )
       CR ROW1  ROW2  ROW1  ROW2
          ROW1  ROW2  ROW1  ROW2  ;

: CHECKER_BOARD  ( -- )
          BOARD  CR CR ;
----- end of program -----------<don't type this line!

To leave the editor and save the program press SHIFT F10
and you will be back in Forth with the " ok " prompt.
To load the program type:

FLOAD BOARD1.SEQ <enter>  and you will see:

BLACK isn't unique        <--- don't worry about this it means
WHITE isn't unique  ok    <--- the Forth also has words BLACK and WHITE

To test the program type:
CHECKER_BOARD <enter>    and you will see the checker board!
If you have an error re-edit BOARD1.SEQ and fix it! and repeat
the above process.  That's all the room this time!

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³  Please move to Lesson 1 Part 6.0  ³
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