The 'System Exclusive Dumps' article in the March 1988 issue gave lots of ideas for using System Exclusive data but no practical hints on actually doing it. Since many readers will probably want to use MIDI Data Recorders (MDRs) to automatically configure their MIDI system for them, it seemed like a good idea to reveal how to go about doing it. In this short article, I will describe how to assemble your own 'composite' files out of the bulk dumps sent by individual MIDI devices.

SETTING UP

You will need to set up two special connection arrangements in order to first prepare, and secondly distribute, the composite files. In normal use, you will be using only the distribution set-up on a regular basis, and will only need to alter this arrangement in order to prepare a new file. All the alterations can be made a permanent part of your MIDI network by using either a matrix switching unit or a couple of MIDI switches or selectors.

In order to distribute (ie. transmit) the files to all the MIDI equipment in your set-up, you will need your MIDI equipment set out in a 'star' arrangement, ie. each unit connected via a Thru box from a master keyboard, for example (Figure 1). A MIDI switcher or MIDI selector box is a good way of switching between your MIDI Data Recorder (MDR) and master keyboard; a cheaper way is to have a 'flying' MIDI lead and manually change connections! However you do it, you will need to be able to switch between using the MIDI Out of your master keyboard and the Out of the MDR.

To assemble the bulk dumps from your equipment you need a similar system in reverse. That is, you need to be able to select from the Outs of each piece of equipment in question, and connect that Out to the In of the MDR. This, again, is best done with a MIDI switcher or selector, but I must confess to using a loose MIDI lead on the MDR and manually connecting it to the required Out - my MIDI network is permanently Thru'd in a star arrangement, but I have never got around to building or buying a MIDI selector box!

PREPARATION

Before assembling the first composite file of all the bulk data in your equipment, it is a good idea to make a safety copy of the data (voices, settings, etc) already in each machine. Performing individual bulk dumps with the MDR is probably a good way of testing that you can save and load bulk dumps successfully, as well as making sure that you are familiar with the required procedure. Remember to back up all the data from each piece of equipment first.

Once you are correctly wired up and everything checks out OK, you need to prepare the paperwork! Take a piece of paper and write down the devices you are going to be sending and receiving bulk dumps from. It is very easy to get confused whilst assembling dumps and this paper record will not only help you keep track of where you are, but will also serve as a permanent record of what is stored in the resulting data file (Figure 2).

ASSEMBLY

OK, you are all set up and ready to go. First, verify that you are ready to transmit from your first piece of MIDI equipment. Make sure that its MIDI Out is connected to the MDR's MIDI In socket, and initiate the MIDI bulk dump from the front panel (the owner's manual should specify how).

Depending on your MDR, as soon as it receives the 'End Of Exclusive' message at the end of this first bulk dump, it will display a message asking you if you wish to Save?, Append? or Stop? Saving the data you have received at this point is wrong, because you want to save the bulk data from all the equipment, not just one item. So select 'Append', as this allows you to add another bulk dump from a different instrument onto the end of the one already sent. (Some MDRs may use different terms here, and you should confirm the details in your owner's manual.)

For each successive piece of equipment, the procedure is the same. You prepare the equipment so that it is ready to send a bulk dump. Make sure that it is connected to the MDR's MIDI In, and then send the dump. You can use the list of bulk dumps as a check sheet, ticking off each piece of equipment as you transfer. When the last device has finished sending its bulk dump data, you can then save the resulting composite file on the MDR.

This file now comprises the bulk dumps of each piece of equipment, stored in the order you sent them. If you had a MIDI monitor or scope program (see 'SOS Shareware' page) on your computer or sequencer, capable of displaying MIDI codes on screen, you would see that the data was organised in the following form:

<F0> Start System Exclusive (SysEx) - start of 1st dump
<nn> Manufacturer's ID
<...> Data
<F7> End Of Exclusive (EOX) - end of 1st dump

<F0> SysEx - start of 2nd dump
<nn> Manufacturer's ID
<...> Data
<F7> EOX - end of 2nd dump

<F0> SysEx - start of 3rd dump
<nn> ID and so on ...

This composite file should now be backed up, ie. copied for safe-keeping (preferably on another disk), and clearly labelled. It is, in effect, a 'snapshot' of the control settings and contents of all your equipment at the time you transferred the data, and so can be used to recall this information at a later date. However, it is good practice to verify that you can load the data back into your equipment now rather than later.

Because each bulk dump contains information at the start which uniquely identifies the manufacturer (eg. Roland) and instrument model (eg. D50) the data is designed for, you can send the composite file to any piece of equipment in your system and each MIDI device will ignore everything except the bulk dump data it recognises.

Now try reloading the dumps and verify that it has actually happened. You should clear the internal memories of each piece of equipment before doing this, and make a backup copy of each instrument's internal data - just in case the bulk dump fails to reload.

CONCLUSION

You now have a file which can be used to restore the current set-up at a later date. This can be used in many ways. It is obviously a useful method of keeping together all the sounds you are using for a particular song. How many times have you worked on a piece of music and returned to it later, only to find that you were unable to get the exact same sounds or feel? Albums have been made using mostly demo takes because the artist was unable to recreate the track in the studio...

With the aid of what you now know, you could assemble all the sounds you need for a studio session beforehand, so that you only need to load a single file when you arrive. This could save a lot of potentially expensive time, and make you look very competent - the first saves you money, the second could make you money! Similarly, you could have a stage set stored on disk ready to be loaded at the soundcheck, rather than discover late in the day that one of the synths has lost its internal memory or your RAM pack's gone walkies!

The composite file is not restricted purely to storing sound data from synths. It could contain complete sequences or drum machine patterns. MIDI's System Exclusive treats all of these items in exactly the same way, and the method of incorporating them into the composite file is exactly the same as I have described above.

A composite MIDI file of the bulk dumps from your equipment should quickly repay the effort involved in producing it. It can save you money you would otherwise have spent on RAM cartridges, and save you time because you no longer need to make copious notes of exactly what sounds, sequences, samples, drum patterns, effects and performance memories you were using at a particular time. Assembling the files is just a matter of keeping your head and proceeding methodically through a set sequence of actions - a small price to pay for the advantages, I'm sure you'll agree!