We put the POWER in DOS!

What's New in PowerBASIC 3.5 since version 3.2?

• $ELSEIF metastatement added for enhanced control of conditional compiling.
• The ampersand character (&) can now be used to concatenate strings:

  MyString$ = MyString$ & "1"

• ASC statement added to allow placing a byte value into an existing string:

  ASC(MyString$, 5) = 65   'change the 5th char to an "A"

  This is functionally equivalent to:

  MID$(MyString$, 5, 1) = CHR$(65)

  However, the ASC statement uses more efficient code.
• ASC/ASCII functions support an optional parameter, which allows you to get the byte value of a character beyond the first byte in a string.
• ASCIIZ string data type has been added. An ASCIIZ string is the same as a fixed-length string, except that the last character in the string is always a null [CHR$(0)].
• CONSIN function returns the status of input (keyboard) redirection. If standard input originates from the console (keyboard), it returns true (-1). If redirected from a file, it returns false (0).
• CONSOUT function returns the status of output (screen) redirection. If standard output displays on the console (screen), it returns true (-1). If redirected to a file, it returns false (0).
• The CVI, CVL, etc. functions now support an optional parameter which is the starting location within a string to extract a value. For example, to extract an integer value from the 5th position in a binary string:

  x% = CVI(My$, 5)

• FRE(-11) function added to return the number of free bytes in EMS memory. Before you allocate a virtual array, you should use FRE to make sure enough memory exists to hold the array.
• Pointer variables now support 'indexes'. This allows you to assign a value to a pointer variable and access data as if it were an array.

  DIM x AS INTEGER PTR
  x = Address???
  a = @x     'get integer at Address&
  b = @x[4]  'get integer at Address& + 8

  In this example, the 5th integer (index pointers all start at zero and are not effected by the OPTION BASE value) is retrieved without us having to modify the Address& value.
• The REDIM statement now supports the optional PRESERVE modifier. This allows you to change the number of elements in an existing array without destroying its contents. Note: REDIM PRESERVE does not work with virtual arrays.
• The RND function has been enhanced to return integer class random numbers using the RND(a, z) syntax. Where 'a' is the lowest random value to return and 'z' is the highest random value to return.
• SETEOF statement has been added to truncate an open file at the current file pointer. This is equivalent to using PUT$ to store a null (zero length) string in binary mode.
• SIZEOF function has been added to return the memory size of variables. Unlike the LEN function, SIZEOF will return the size of the storage buffer available in ASCIIZ strings and the size of a string's handle (not the size of the string contents).
• STDERR statement has been added to print data to the "standard error device". Typically, this is the screen, and output using STDERR can not be redirected to a file.
• STDIN/STDIN LINE statements have been added to read keyboard data from the "standard input" device. Typically this is the keyboard. However, if a file has been redirected to your program STDIN will read from the file instead.
• STDOUT statement has been added to print data to the "standard output device". Typically, this is the screen, and output using STDOUT can be redirected to a file or other device. Note: Only text printed with the the STDOUT statement will be redirected to a file. The PRINT statement prints data to the screen, regardless of output redirect status.
• TRIM$ function added to trim the spaces (or other optional characters) from both the front and back of strings.
• User-Defined Type and Union variables now support static arrays:

  TYPE a
  b(1 TO 50) AS INTEGER
  c AS LONG
  END TYPE

• Virtual Arrays in EMS memory. PowerBASIC now allows you to create numeric, fixed-length string, ASCIIZ string, and user-defined type arrays in EMS memory up to the LIM specification (16 megabytes).

  DIM VIRTUAL x&(1 TO 10000)

  If you are debugging a program with virtual arrays and an END statement is encountered (or a program ends with an error), you can no longer watch elements from a virtual array. You must restart the program. In order to create a virtual array, an EMS driver (such as EMM386.EXE or QEMM386.SYS) installed on the computer running your program. For DOS and Windows 95 users, the easiest way to add EMS memory is to run the MEMMAKER utility included. When asked if you want to add EMS memory, answer with a "yes". Or you can manually add the EMM386.EXE driver to your CONFIG.SYS file with the following line:

  device=C:\DOS\EMM386.EXE

  Be sure to use the correct drive and directory if the EMM386.EXE driver is not located in your C:\DOS directory. Windows NT uses will need to create a shortcut to their DOS program and add EMS memory in the "memory" tab of the properties dialog for their program. For additional information, select "Help" from the Start menu and search for the keyword "EMS".
  
  Important: The ARRAY SORT, SCAN, INSERT and DELETE statements will not work with virtual arrays. For an example of sorting a virtual array, see the SORT.BAS source file in the EXAMPLE directory. The SWAP statement does not work with virtual arrays. You may not pass a virtual array to a Sub or Function by Reference. Only by Value. See 'Virtual Arrays' in chapter 5 of your User's Guide for additional information.
• We have compiled a list of Frequently Asked Questions (FAQs) and placed a series of text files with these questions and their answers in the PB35\FAQ subdirectory. You'll find information such as linking .OBJ's created in Borland C or Microsoft C into your programs and saving graphics screens from EGA and VGA screen modes to a disk file.
  
  Important: Because of the added support for virtual memory arrays and other features, any unit files (.PBU) or library files (.PBL) created in earlier versions of PowerBASIC will need to be recompiled using version 3.5 of the compiler.

PowerBASIC Help Kit

Starting with version 3.0c of PowerBASIC, a full copy of the PB3 Help Kit is provided so that you can create custom add-on help files for use with the PowerBASIC IDE. The primary purpose is to allow vendors of programming tools compatible with PowerBASIC to make on-line help easily available to you. However, there are many other uses as well. For example, a programming team leader might create a help file to describe required documentation style for the group. Or you might use it to remind yourself of structure and goals. Regardless of the task, the tool is now available, just add a bit of your imagination.

Complete documentation for the PowerBASIC Help Kit is provided in the add-on help file USERHELP.PBH. Just copy that file into the directory which contains PBHELP.PBH, and press SHIFT-F1. This add-on help file will provide all the guidance you need to create your own help files. Of course, add-on help files will only work with the PowerBASIC IDE. They are not designed to be used with user-written programs.

MAKEHELP [source[.txt] [helpfile[.pbh]]]

MAKEHELP

MAKEHELP userhelp.txt

MAKEHELP userhelp.txt userhelp.pbh

The PowerBASIC online manuals