INSTIGATOR INVESTIGATED

David Spencer takes a look at a mammoth new utility package from Dabs Press.

Instigator is a package which has been promised for a long time, but has suffered a number of delays - most notably the need to make it fully RISC OS compatible. Now, however, the package has finally been released.

WHAT DOES IT OFFER?

There are over eighty star commands in the 53K Instigator module, and I won't attempt to detail them all. Instead, I will describe them in the categories that are used in the manual. The first set of commands deal with pop-up windows, but should not be confused with WIMP-type windows. Instigator's own windows consist of normal text windows with a double border around them. Windows can be opened and closed at will, and Instigator will attempt to save the area of screen covered by the window. It is also possible to run a command in a window, in which case the user is prompted to press a key afterwards, and the window is closed automatically. The foreground and background colours of the windows can be changed, but currently only one window can be open at a time. My only quibble with this system is that the saved area of screen is grabbed as a system sprite. It would have been more sensible for Instigator to claim some memory from the RMA and create a user sprite area.

The second feature is the line editor, which provides word processor editing when entering commands, or Basic, or indeed anything. When in this mode, the line currently being entered can be edited by moving around the cursor and inserting and deleting characters at will. This function is performed by intercepting the RISC OS read line routine, and the line editor should therefore work with just about any package.

Next on the list is command archiving. Instigator can optionally record everything typed in, and this can subsequently be recalled as a list, or each line can be brought up one by one using the Page Up and Down keys. For example, if you need to reissue a long command that you typed previously, you simply press Page Down until it reappears on the screen and then press Return to issue it. Related to this is the cut and paste option which allows an area of text from the screen to be highlighted and copied into a buffer. The contents of this buffer can then be forced into the keyboard buffer, as if it had been typed in. This provides a very powerful copy option.

The filename completion system allows partially entered filenames to be automatically completed. For example, suppose you typed 'LOAD "$.UTILS.PR'. A single keypress would make Instigator search the $.UTILS directory for files starting 'PR', and complete the name if possible.

There are a large number of screen related commands. There is a screen dimmer which blanks out the screen after a period when the computer has not been used, and turns it back on when a key is pressed. You can also halve the brightness of the screen, or turn it off completely. There are fast screen save and load commands, including a compressed format, and all commands causing VDU output can be sent to a file, and replayed later at a variable speed. A very nice feature is the smooth scroller which replaces the RISC OS line-at-a-time scroll with a very smooth variant. For the brave, there are commands to directly reprogram the video controller, and to implement extra modes using a feature built into RISC OS. Numerous commands exist for handling colours, including the ability to store a number of palettes in memory at once.

The general commands include some to load and save the operating system variables and CMOS RAM. A full scrolling memory editor is supplied together with a memory mover and filler, a memory find, and a full disassembler. File commands allow a list of open files to be displayed, confirmation to be sought before deleting files, and also perform the usual operations of Catall, Exall, Find and Goto. Another set of commands simplify the entry of complex pathnames by allowing simple names to be tagged to directories - again a very powerful feature. Instigator's disc sector editor will edit a wide range of formats, including PC discs, and has facilities to search the disc, and to transfer sectors between memory and the disc.

Miscellaneous commands are provided to list a Basic program from a file, control the RISC OS hourglass, issue SWI calls, and display lists of available SWIs. Finally, the documentation hints that future versions of Instigator will include extra features, and if Dabs follow their normal policy then upgrades will be available at little or no cost to registered users.

DEMONSTRATION DISC

As well as the program disc, Instigator is supplied with a demo disc which contains among other things a rolling demo of all the features. This lasts for about half an hour, and while you are only likely to use it once, it does show the new user exactly what Instigator is capable of. There are also separate demonstration programs to show the use of new modes, and other Instigator features.

THE RISC OS INTERFACE

One of the problems with implementing utilities as star commands is that you have to leave the friendliness of the Desktop to issue them, and this can prove confusing to beginners. To get around this, the Instigator disc includes a Desktop application which can be installed on the iconbar. Clicking on the icon then brings up a window containing all the Instigator commands. Subsequently, clicking on a command will execute it if no parameters are needed, otherwise it will pop up a further window asking for the parameters, and give you the option to execute the command or to abort it. This might sound long-winded, but it does provide an interface to Instigator from within the Desktop.

DOCUMENTATION

Instigator is supplied with a 128 page A5 wire bound manual. This starts off with an overview of the features offered, and details of installing and running Instigator. The individual commands are then described, not in alphabetical order, but rather split into sections according to their function. The descriptions are adequate in most cases, but it is not always possible to describe all the details. For example, the section on defining new modes makes no attempt to describe the necessary data, but instead refers you to the VIDC data sheet which is available from Acorn.

My only moan about the manual is that it has no real index, although the contents section is fairly comprehensive. This can make it difficult to locate the entry for a particular command, especially because of the ordering, and the fact that the manual is written in book style, rather than having one command per page.

CONCLUSION

When I first looked at Instigator, my immediate impression of the package was that a lot of its features were little more than gimmicks, and I still doubt the usefulness of some of them. The manual suggests that a number of features, such as the window system, can be incorporated into your own programs. I am always wary of this, because it restricts the program for use on systems which have that particular utility package. However, using the package for a few minutes soon convinced me that it provides a wealth of very useful features, including just about everything offered by other toolkit packages. In particular, the memory editor and disassembler are vital to most programmers. When you consider that at £50 Instigator is no dearer than its closest competition, notably Clares' Toolkit Plus, then it seems even more attractive. To sum up, if you need a toolkit then I can highly recommend Instigator.
ProductInstigator
SupplierDabs Press,
 5 Victoria Lane,
 Whitefield,
 Manchester M25 6AL.
 Tel. 061-766 8423
Price£49.95 (inc. VAT)