Powerbase Shareware Database
!Powerbase
Powerbase is for
Acorn 32-bit machines and their successors.
None of these programs will run on a PC or Mac.
For information about Acorn Computers and RISC OS click the cogwheel above or see
The RISC OS Site
Richard Atterer's history of Acorn
and follow the links from each site.
Click here to find out about Powerbase in general.
Click here to go to the Download area
Click here to retun to Boulsworth Main Index
What's New?
Site last updated:
09 May 2012
The most recent version of Powerbase, v.9.84 (08-05-2012) is now available for download. Two new field types have been introduced:
- A JPEG button to add to the family of Text, Sprite and Draw buttons. Like the older three types the new one will accept only the specified file type (JPEG) and copies the dropped file into an automatically-created tree of subdirectories within the database directory.
- A Scaled image field which will accept, and scale to the defined rectangle, files of type JPEG Sprite and Draw. "But wasn't that introduced some time ago?" you ask. Yes, it was, but that is what I called a Remote field which stores only the pathname of the image leaving the image file itself where it was. In other words the image is not part of the database but is referenced by pathname. This field type is now called a Referenced (rather than Remote) scaled image field. The new type is more like the old Text block and Picture fields in that it copies the image into the database directory in the same way as the JPEG, Text, Sprite and Draw button fields referred to above.
The two Scaled image field types can now be made to automatically display their images in an external application (!EasyView is recommended) as you browse the records. Consistency with other graphical field types is ensured by using the Ctrl-ADJUST click to toggle the feature ON/OFF. Temporary alterations to the scaling option (which formerly used Ctrl-ADJUST) are now made using Alt-ADJUST.
There are also three new script commands:
- !SLIDESHOW enables you to display a specified sequence of records by clicking SELECT (and to go backwards by clicking ADJUST) without worrying about where the mouse pointer is. The required records may be specified in various ways.
- !POINTER is meant for use in conjunction with !SLIDSHOW: if the position of the pointer is irrelevant then why not turn it off? !POINTER enables you to do just that (and, of course, turn it back on). You can now view your selection of records on your big flat-screen monitor while sitting back in your armchair using wireless mouse like a TV remote.
- !PREPROCESS. It has been possible for a long time now to search for a record in a more "human-readable" way than by typing the key. This is useful where complex, multi-part, keys are concerned. Many script commands make use of lists of keys and it is now possible to take advantage of this feature by executing the !PREPROCESS command prior to whatever script command handles the list.
The documentation in HTML format has been completely revised so that all the newest features are fully described.
Powerbase SUDOKU
!Sudoku is a database which makes use of some of the newest features of Powerbase and also demonstrates how databases can be customised with non-standard features. Each record has just two editable fields: a Name field and a 9-column scrollable list in the form of a Sudoku grid. The custom features enable you to:
- type in a Sudoku puzzle then "fix" it so that only the blank squares are editable thereafter. (The puzzle can be "unfixed" if you made a mistake when entering it!)
- set about solving the puzzle by filling in the blanks. "Illegal" entries will be disallowed.
- click a Help button to tell you what numbers are allowed in the current square.
- reset the puzzle to its initial state if you make a mistake.
- solve the whole thing automatically (but you don't really want to do that, do you?)
- generate new puzzles automatically.
- merge puzzle into an Ovation Pro document at the click of a button. Print the puzzle on paper, with or without the addition of numbers which could go in each blank square.
Get !Sudoku from the Download area. Requires Powerbase v.9.44 or later; v.9.84 recommended.
Distribution list generator
!Distrib is a customised database which might prove useful for anyone who distributes magazines or newsletters to a list of subscribers, some of whom act as sub-distributors to subscribers living nearby. It will work if some of the latter subscribers are themselves sub-sub-distributors and so on! A mixture of postal and hand-deliveries is supported as are extra copies (e.g. for placing in a club or school) and large-print copies. Mailing labels may be printed for postal deliveries. The customisation library was written in response to a real situation faced by a long-term Powerbase user. The version now on the website incorporates a number of changes requested by the user.
Get !Distrib from the Download area. Requires Powerbase v.9.44 or later; v.9.84 recommended.
Manuals and Tutorials
The extensive improvements to Powerbase, especially those introduced in versions 9.25, 9.40 and 9.70 rendered the old documentation woefully out of date. The Ovation Pro and PDF documentation has now been withdrawn and only the HTML-based form, as described below, is supported.
!PbaseDoc — comprehensive HTML documentation
The HTML versions of the tutorials and the reference manual have been incorporated in an application !PbaseDoc. Since this is especially easy to modify and keep up to date it should henceforth be regarded as the definitive version of Powerbase documentation. Besides being extensively illustrated much attention has been devoted to the problem of navigating the large reference manual which constitutes the main part of the application. To this end the manual features:
- a list of chapters
- individual contents lists at the start of each chapter
- an alphabetical index
all of which are provided with HTML links. In addition, there is copious cross-linking between chapters and between parts of chapters, wherever the text refers to another part of the manual. If you follow such a link you will usually find that a return link is provided to get back to where you were before. Button links occur frequently to take you to the start of a chapter or to an illustration of an important dialogue box.
PbaseDoc can be run from the new Help button on Powerbase's iconbar Info window, provided that PbaseDoc and your web browser have both been "seen" by the filer. The very limited Helpreader text incorporated in previous versions of Powerbase has now been removed along with the menu entries which invoked it.
32-bit compatible sliding-heap module
The sliding-heap module was written by Steven Haslam in 1992. It creates and manages any required number of
memory blocks at the top of a program's Wimpslot and allows them to be resized, scrapped and re-created at will.
Because increasing the size of a block is achieved by moving up blocks at higher addresses, and shrinking or
destroying a block results in the "hole" being closed by other blocks sliding down, memory fragmentation is avoided.
The module has now been upgraded to make it 32-bit compatible. Visit the Download area
to obtain a copy of this module for use in your own programs, along with extensive documentation, a library of
BASIC routines for accessing the module's SWIs and a demonstration of the module in action. Thanks are due to
Christopher and Harriet Bazley for undertaking this work.
Powerbase is shareware. Registration costs 10 GBP, payable by cheque to Derek Haslam.
You may register by credit card through APDL.
This site (http://www.boulsworth.co.uk/) is for distribution of Powerbase,
Derek Haslam's shareware database for RiscOS computers.
for more information about Powerbase or if you have comments about the website.
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