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Pandora DXessory

A Practical FM Editing Solution?

Article from Sound On Sound, February 1989

Martin Russ explores the merits of Desk Accessory programs with a look at this Atari-based 'pop-up' DX editor from Pandora Technology.

Martin Russ explores the merits of Desk Accessory programs with a look at this Atari-based 'pop-up' DX editor from Pandora Technology.

It's the standard nightmare: you're in the middle of creating a sequence and things are all coming together nicely, when you discover that the string pad from the DX7 is clicking at the start of every chord! Knowing that you have left the Oscillator Sync on is really only of use if you can edit it, but that means saving the work so far, quitting the sequencer and loading an editor, or even plunging into the DX's onboard editing. Or does it?


Figure 1. DXessory loads as a Desk Accessory and is called up from the Atari's Desk menu.

Apart from using another computer to perform the editing tasks, the only affordable solution to the above dilemma for most of us mere mortals is going to fall into one of three areas: Desk Accessories (DAs) are small programs which are loaded into memory when you first turn on or reboot the computer. They register themselves with the operating system and then enter a dormant state, enabling you to use your computer as normal. To wake one up, you usually select the appropriate option from a menu - such as the Desk menu on the Atari ST (see Figure 1), or press a 'hot key' combination, such as (Alt] and [Shift] together. The Desk Accessory then bursts into life, popping onto your screen and temporarily suspending the major functions of any other program which might happen to be running at the time. When you are finished, you close the desk accessory (this puts it back to sleep) and you can continue where you left off with the original program.

Switchers are programs which enable you to partition your computer's memory into separate areas, in which you can then run different programs. You can usually arrange to load in the programs with a couple of mouse clicks. Only one of the programs runs at any one time, the others are just stored away somewhere else in memory. Changing or switching (hence the name) between the programs is usually just a matter of pressing an obscure combination of keys on the computer keyboard. The Switcher program that I use is available from the SOS Shareware pages (Disk 16) for a mere £7.

Multitasking refers to the operating system of the computer itself. A multitasking operating system allows the computer to share its available processing power between several programs. There are two approaches to achieving this: 'time sharing', which allocates an amount of processor time for dealing with each program in turn; and 'backgrounding', which utilises the spare time that most programs have, especially when waiting for a user's input, to run other programs. The Atari ST only has limited capabilities in this area. For instance, the sound/MIDI ports can be run via interrupts whilst the rest of the ST is busy doing graphics. The Commodore Amiga and the Acorn Archimedes are possible routes to more sophisticated multitasking. The Apple Macintosh's MultiFinder is like a cross between a Switcher and a backgrounder, rather than a multitasker. For true running of several programs in parallel, you need a more powerful machine based upon a different type of microprocessor, such as the Inmos Transputer chips. Indeed, Atari and Commodore are both working with this sort of technology for their next generation of computers.

All three methods give the end-user the ability to flick back and forth almost instantly between two or more programs. The difference lies in the ease of use and the features. For example, if you copy a desk accessory program onto the disk you use to boot up your computer, then it will always be available 'just a mouse-click away!' - although you will have to wait for it to load into memory every time you re-boot the machine. Not a burden really. Switchers and multitaskers often mean that you have to stop what you are doing and load in another program, thus effectively interrupting any creative process that was taking place. Conversely, desk accessories occupy valuable memory all the time they are lying in wait, ready to be 'popped up', so they can reduce the amount of available storage. Whereas a switched or multitasked program can be loaded only when it is needed (provided your computer has enough memory in the first place!). So, are there any ST-based desk accessory editors for the DX7?


The DXessory from Pandora Technology is a desk accessory for the Atari ST (520 and 1040 models) and Mega STs, which provides not only a pop-up editor for use within sequencers and other programs, but also a very interesting and effective way of doing it! As the name suggests, it is designed to control the Yamaha DX series of synthesizers, specifically the 6-Operator models: DX7 MkI, MkII and DX7S, TX7, TX216, TX816 and TX802.

Figure 2. DXessory's main screen showing the pop-up Utility menu.

The opening screen (Figure 2) is the main editing page, with MIDI channel selection on the far right, and everything else clustered around the large graphic area to the lower left of the screen. Unusually, for a dialogue box, there are four pop-up menus dealing with Mode (choice of synth), Loading and Saving voices to edit, Display options, and the Utility mode (Bank transfers, Startup file, etc).

The main graphic area is the key to the functionality of the program - you click on a parameter and the relative values for all six operators will be shown, although envelope shapes can be displayed for just one or all six operators. The parameter name boxes serve a dual purpose: they change to show the actual value of the parameter being edited when the mouse is moved over them, thus saving space and avoiding screen clutter! A truly innovative use of GEM - full marks.

The two other places where graphics can be used to advantage concern the Algorithm and the Scaling, and both of these are allocated their own areas with clear diagrams of the current Operator arrangement, Rate and Level Scaling. The usual convention for using the ST's two mouse buttons is employed: the right-hand button increases the value, whilst the left-hand button decreases it. Choosing the active Operator is accomplished by clicking on one of the six numbered boxes, which are sensibly located in the centre of all the parameter boxes.

Separate copying of the envelopes and the scaling is provided by two further dialogue boxes. All the global controls tend to be on the right of the screen - Feedback, LFO parameters and the Name of the voice. Selecting the function edit from the Mode menu replaces these global commands with the DX's performance parameters, again showing a complete and consistent approach. The one major omission seems to be a 'mouse play' feature (as found on Dr.T programs), where the mouse can be used to select notes and velocities - DXessory restricts you to a note event after each edit, or Function key-driven fixed note selections. Overall though, it shows evidence of a great deal of careful thought and planning to make it quick and easy to use - and it works beautifully!

Figure 3. DXessory's Bank Manager offers fullblown voice librarian facilities for organising your DX sounds.

As well as the editing functions, accessing the Bank Manager from the Utility menu provides a full DX librarian program (Figure 3), enabling disk storage of a large number of banks of 32 voices. (Single voices can be saved and loaded from the main edit page, of course. Although I had some problems using the edit page's MIDI Receive functions with my DX7 MkI, the Bank Manager worked fine - I only wish real-life bank managers were as friendly!) The librarian follows the now traditional layout, with two sets of 32 voices arranged on the left and right sides of the screen, with icons for Load, Save, Edit, Insert etc in the centre.

Searching through the menus reveals an interesting feature - there is no Quit, Exit or OK box anywhere! Before you panic, I should explain that clicking or even moving outside the edit screen boundaries will provide an escape route; and since this will normally mean that you click on one of the windows from your sequencer, it seems a very intuitive thing to do. Because DXessory remains in your computer's memory permanently (barring resets or loss of power, of course!), you can quit from one program, load another, and yet when you activate DXessory again, it will have the same voice as you left it when last editing.

Figure 4. DXessory's MIDI instrument channel assignments are accessed from within this dialogue box.


As I mentioned above, the problem with desk accessories, like DXessory, is that they use up RAM, and this restricts the available storage space left for musical events. The advantage is that this space is allocated at the time of loading the accessory, so there are no problems later with insufficient memory to load another program, as can happen with Switcher devices! DXessory uses about 80Kbytes of RAM. So, assuming between two to four bytes are required per note event, this could reduce the maximum note storage capacity of your computer by something like 20-40,000 notes, depending upon your sequencer. The obvious area of concern here would be when you are running larger music programs, like C-Lab's Notator, where the reduction in note storage could be very limiting. The advantages of co-residency of editor and sequencer could well force an upgrade to a Mega ST for the power user!

Co-residency has many potential traps for the unwary programmer. I tried DXessory with Steinberg Pro24 III, Hollis Research Trackman, Intelligent Music M and System Exclusive Iconix to assess its performance in co-operation with a wide range of potential sequencing partners. Pro24 still worked, although making edits with a sequence running seemed to be trouble-prone - DXessory managed fine when Pro24 was stopped. Trackman behaved perfectly, with sequences running whilst editing and no hanging notes. With M running, DXessory was slow to redraw itself on-screen and the edits themselves were slowed down considerably, with occasional sustaining notes resulting. Iconix redrew itself beautifully and worked fine, although editing with a sequence running did produce lots of droning notes!

In a world of constant updates and seemingly endless revisions, it hardly needs me to tell you that it is going to be difficult for programmers of desk accessories to maintain perfect operation with all programs at all times. The best guarantee of compatibility is really how well the sequencer program is implemented, since DXessory seems to work very well with the neatly coded Trackman, and less with the sometimes rather fragile M! The nature of the Atari's operating system forces desk accessory programmers to follow the rules closely in order to realise a working program, and it is a pity that the same stringency does not apply to ordinary application programs. DXessory comes on a copy protected 3.5" disk, and you always need to boot with the disk in drive A:, but it does free the cartridge port for other dongle-based programs like Pro24 or Trackman.


This is a very well-crafted piece of software, with careful attention paid to detail and usability. The choice of Desk Accessory format means that some problems of compatibility with other programs may occur, and this has to be weighed against the considerable advantage of having a DX editor and sequencer (say) instantly available at the whim of the user. It means an end to searching through banks of DX sounds looking for a slightly brighter string sound or a bass with less edge; you can edit to your own taste, in situ!

With an idea as good as this, it won't surprise you to learn that there are other editors in the Pandora range - a Korg M1 editor, for example.


£99.95 inc VAT.

MCMXCIX, (Contact Details).

Also featuring gear in this article

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Shape of Things to Come

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High Noon!

Publisher: Sound On Sound - SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.

The current copyright owner/s of this content may differ from the originally published copyright notice.
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Sound On Sound - Feb 1989

Donated & scanned by: Mike Gorman

Gear in this article:

Software: Editor/Librarian > Pandora > DXessory

Gear Tags:

Atari ST Platform

Review by Martin Russ

Previous article in this issue:

> Shape of Things to Come

Next article in this issue:

> High Noon!

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