ZBasic v4.20 for the Apple II - Update Information

This file contains some information that didn't make it into the manual,
such as new changes to the system, new commands or other enhancements, etc.

1 May 1987 - Added single keystroke commands in the Line Editor
     There have been two single key commands added to the command environment
     editor.  They operate in the same way as the other single key commands,
     such as the arrow keys, ';', etc., which means they must be the first
     key typed on the command line.  The first is the ESC key, and the second
     is the '+' key.  Pressing the ESC key will take you into the full screen
     editor with line-numbered lines.  This is the inverse of pressing the
     ESC key while in the full-screen editor (which returns you to the line
     editor).  The '+' key will take you into the full screen editor with
     line numbers stripped from your program lines.

1 May 1987 - Use of auxiliary slot ram cards
     Since ZBasic automatically uses a /RAM volume to speed up program
     development time, it would be nice to have some way of setting up such
     a volume during boot-up.

     For those of you with Applied Engineering's Ramworks card and the
     accompanying Prodrive software, I have some bad news.  Since the
     Prodrive program is released as a BIN type file, the only way to
     execute it is from within the Applesoft environment, or from within
     ZBasic by first using the BLOAD function to get it into memory, and
     then executing it.  You also might want to contact A.E. and see if
     they have a .SYSTEM version of the program available.  I will be working
     on modifying the existing Prodrive program to make it act more like
     what Checkmate Technology supplies with their ram card.  Read more
     about it in the following paragraph, and look for the modification
     instructions in the Z newsletter.

     For those of you with Checkmate Technology's Multi-Ram card, better
     news.  The MRAM.SYSTEM program supplied with the card is just what the
     doctor ordered.  If this is the first .SYSTEM file in the disk directory
     then it will be automatically run during boot up.  It will set up the
     ram card as a ProDOS volume, and then automatically load and execute
     the next SYS type file in the directory.  There has to be a couple of
     modifications done first, though, to make the /RAM volume a little more
     compatible with ZBasic.  First, get into Applesoft BASIC, then type:

     BLOAD MRAM.SYSTEM,TSYS,A$2000
     CALL -151
     2005:52 41 4D 33 <cr>
     298B:52 41 4D 33 <cr> (that's the return key)
     2547:D2 C1 CD B3 <cr>
     CREATE RAM3.SYSTEM,TSYS
     BSAVE RAM3.SYSTEM,TSYS,A$2000,L3226

     This changes the name given to the /RAM volume from /MRAM to /RAM3.
     This way, ZBasic will recognize the /RAM3 volume as a ram disk.

7 May 1987 - Added options for the LOCATE statement
     The locate command has been changed slightly so that either the X
     coordinate, the Y coordinate, or both, may be omitted from the statement.
     If either coordinate is absent, the compiler will generate the necessary
     code to use the current value(s) for the missing coordinate.  e.g.:

          LOCATE ,,0

     will allow the cursor to remain in it's present position, but will turn
     it off.  Another example:

          LOCATE 0,10
          PRINT 'HELLO THERE!';
          LOCATE ,11
          PRINT 'HELLO THERE AGAIN!'

     will first position the cursor to line 10, column 0, and print 'HELLO
     THERE!'  Since there is a semicolon at the end of the print statement,
     no carriage return is generated.  The next LOCATE statement moves the
     cursor to line 12, but leaves the column position alone (it was left
     at position 12 by the PRINT statement), so the next string printed will
     be printed away from the left margin.

7 May 1987 - OPEN 'C' expanded parameters
     Options have been added for the various parameters that can be specified
     with the OPEN 'C' statement.  (see the reference manual for the syntax)

     The slot # must be the slot that contains the Super Serial Card or
     equivalent. (not just -1 or -2 as stated in the manual)

     The baud rate can be any baud rate supported by the Super Serial Card:
     50, 75, 110, 135, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200,
     9600, and 19200.  Of course, this is no guarantee that your computer
     has a fast enough clock speed to support the higher baud rates.

     The parity can be one of the following:
          0     none
          1     odd (odd total number of ones)
          2     even (even total number of ones)
          3     mark (parity bit always 1)
          4     space (parity bit always 0)

24 December 1987 - ProDOS now included
    ProDOS is now included on the distribution disk.  All you have to do
    now is use any disk copy utility to make a working copy of your ZBasic
    disk, and then use that disk to boot directly into ZBasic.  If you are
    using the 64K version of the system from a 5.25 inch disk, you'll
    still have to put a copy of ProDOS on that side of the disk.  We only
    had room to put it on the 128K side of the 5.25 inch disk.

    If you're using a 3.5 inch disk, you obviously don't have to worry
    about which side is which.  The two different versions can be found
    in two subdirectories on the disk.  We have also added a program on
    the disk which is run automatically when you boot the disk.  This
    program will allow you to select which version to run at boot time.

22 January 1988 - enhanced POINT function
    The point function has been enhanced to allow you to read characters
    from the text screens.  The syntax is exactly the same as specified
    in the manual, except that the value returned is the ASCII code for
    the character at the position specified.

    The coordinates are normally specified using the ZBasic Independent
    Coordinate System, but you can use a POKE &85,0 to allow a program
    to specify a position using row/column coordinates (like in the
    LOCATE statement).

    As mentioned previously, the value returned is the ASCII code for
    the character at the position specified.  No distinction is made
    between normal or inverse text, or normal or Mousetext.

    The sample program MOUSECLICK.BAS demonstrates this function by
    allowing you to move the mouse pointer on the screen and click on
    a letter.  The program will pick up the letter from the screen and
    display it for you.

    One application for this function would be a program using overlapping
    windows and/or pull-down menus.  The POINT function could be used
    to save the characters on the portion of the screen that will be
    overwritten by the new window, so that the screen can be restored
    after the new window is closed again.

9 February 1988 - enhanced CALL statement
    The CALL statement will now accept a numeric expression as an
    argument specifying the address to call.  Previously, the statement
    would only accept a constant.  What this means is that you can now
    use an integer variable to hold an address of a subroutine, and then
    access this subroutine by CALLing the variable.  For example:

        Monitor% = &FF69 : REM Address on monitor entry point
        .
        .
        .
        CALL Monitor% : REM Enters the Apple Monitor, CTRL-Y to exit

    This is most useful when you DIMension an array to reserve memory,
    and then use this memory to BLOAD a machine language subroutine.
    You can then use the VARPTR function to retrieve the address of
    the array, and then use this address in the CALL statement.  In
    the 64K version, both CALL constant and CALL expression perform a
    CALL within the main 64K bank of memory (since the 64K version only
    supports the main 64K bank.)  The 128K version handles the two
    different types of CALLs differently.  If you CALL constant, ZBasic
    will assume that you wish to call a subroutine in the currently
    executing program, which resides in the auxilliary bank of memory.
    CALL expression will call a subroutine that resides in the main bank
    of memory (which is where ZBasic's variables are stored).  This
    allows the technique of BLOADing a subroutine described above.  You
    can also POKE a subroutine into memory and CALL it this way, since
    POKE also operates on the main bank of memory.

11 March 1988 - Enhanced INKEY$ function
    The INKEY$ function has been enhanced so that in addition to returning
    a keypress from the keyboard, it will also return information on
    whether one of the Apple keys was pressed at the same time.

    Normally, the INKEY$ functions returns a string with a length of 1 if
    the user pressed a key, or a length of 0 if no keypress was available.
    With the new INKEY$ function, the string will have a length of 2 if
    the Open-Apple and/or Solid-Apple keys were pressed at the same time
    as the normal keypress.

    The string returned in this instance will contain two characters.  The
    first character will have one of three ASCII values.  If the Open-
    Apple key was pressed, the character will have an ASCII value of 1.
    If the Solid-Apple key was pressed, the character will have an ASCII
    value of 2.  If both Apple keys were pressed, the character will be
    an ASCII 3.  The second character of the string will be the value of
    the standard keypress.  If ONLY one of the Apple keys was pressed
    (without a normal keypress), INKEY$ will still return a NULL string

    There is a sample program included on your ZBasic master disk that
    demonstrates a method of recognizing an Open-Apple and/or Solid-
    Apple keypress event.  The program is named INPUT.APPLE and can
    be found in the SAMPLE.PROGRAMS subdirectory on the 128K side of
    the diskette.

15 Mar 1988 - Cross-reference utility added
    Version 4.2 of ZBasic includes a cross-reference utility (written in
    ZBasic, of course) that you can use to get information on your ZBasic
    programs.  The program source code and a short documentation file can be
    found in the XREF subdirectory on the 128K side of your ZBasic master
    diskette.