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SDA Promidi Studio System

Software for the IBM PC

System Design Associates' Promidi Studio System is a powerful sequencing package for IBM and compatible computers that records straight to disk. Ian Waugh checks it out.

An IBM PC sequencing package powerful enough to boast direct-to-hard disk recording is sure to attract its share of attention.

Play/Record screen

"CAN YOUR SEQUENCER do this?", asks the advert: "Record three million MIDI events? Record songs direct to disk? Play songs without waiting for them to load?" (Trick question.) "Does it give you an unlimited number of tracks and an unlimited track length?"

Unless you have Promidi, I think you'll have to answer "No" to most of these. Promidi differs from yer average MIDI sequencing program in several ways. It records direct to disk; it needn't be a hard disk but if you want to store 3,000,000 events you'll need a 20Meg drive. A floppy disk will store about 60,000 events.

It stores music as files on disk instead of as tracks in memory. If you're used to "conventional" sequencers, this will take some getting used to. But get used to it you must, for it is the hub of Promidi's operation.

The package comes with its own MIDIcard which plugs into one of the slots at the back of the computer. It contains its own RAM and part of the program loads into the computer's RAM and part into the MIDIcard. Updates will be in software form (for the price of a disk and p&p) so you don't have to worry about forking out for a new card.

It has a timing resolution of 192 clocks per beat. There's nothing new about that, but it also has a tempo resolution of up to 762 beats per minute. Yep, that's fast.

You can install a RAM disk to speed up disk operations. While a hard disk won't increase Promidi's actual recording ability, it will speed up some of its other disk-intensive activities such as filtering, mixing and editing (all coming up in good time).

As it saves direct to disk the program requires relatively little onboard RAM. The minimum requirement is 320K, which still leaves room for a small RAM disk. A hard disk will improve the Punch In/Out function by a factor of about five times, a RAM disk will increase it by a factor of 19.

Another consequence of saving direct to disk is that should a failure or power loss occur, your data is already there on disk. One word of advice if you use a RAM disk, however, don't forget to back it up.

Promidi was developed by SDA - System Design Associates of America, not to be confused with Steinberg Digital Audio which is something else altogether.

So, introductions over, let's get started. The version under review is E1.2, the manual is 94 pages long and contains 6 pages of addendum.

Getting started

THE FIRST THING you have to do is make a bootable disk from the one supplied. If you've a hard disk you can install it quite easily. If you've a double disk drive it won't take very long but if you've only one drive your arms will drop off swapping disks during the conversion process.

This is as good a time as any to say that the system was mode for hard disk although it is still eminently useable with 5 floppies.

The conversion, copying and installation over, you boot the disk and get a few screens of welcoming words leading to the Main Menu which has six sub-screens: Directory, Play/Record, Mixing, MIDI Channel, File Maintenance and Filter. The program is menu driven, mainly by the function keys. Pressing Escape at any time will take you back through a menu or two, eventually returning to the Main Menu. You'll never get lost, although you may occasionally be confused over which screen (or sub-screen) you need to do a particular job.

Most of the menu screens contain diagrams of the function keys with arrows pointing to a description of their function. Reading a screen is a little like following a route map.

You can call up Help screens from any part of the program by pressing "H". The Help files are stored on disk and if you keep them on your work disk you'll be left with a meagre 22K of music storage space. They can be removed, however, once you're comfortable with the program; alternatively you can use an empty work disk - or get a second disk drive or hard disk.


RECORDING IS NOT just a matter of pressing a button and playing. First you must select/create a directory and then enter a filename for the track/music line you are going to play.

Filenames can be up to eight characters long and they are suffixed with a version number. If you're really in a hurry you can jump in and go by pressing "T" to create temporary files called TV01, TV02, TV03 and so on. You can rename them later. Promidi allows 99 versions of a file to appear in each directory - I wish you the best of luck sorting them out. Pressing the "=" key lets you draft a note of up to 1036 characters to accompany each file. Useful.

Having recorded a file you can play it back straight away by pressing F1 (to nominate the file as a playback file) then F2 (to play it). To record one file while another plays back you must designate both a record and a playback file. This requires a brief excursion to the Directory Screen to select the Playback file.

To playback several files at the same time you must mix them. You can do this from the Play/Record screen with the Listen function (which automatically produces a file called $LISTEN) or from the Mixing Screen (which lets you choose your own filename). You can then play this new file while recording another. If you want to mute a track/file within the mixed file you have to do another mix.

Promidi's powerful recording facilities will record multiple MIDI channels at once. You can extract specific channel information from the file and edit it.

On the Play/Record screen you can adjust the tempo and fast forward and rewind to a specific location in the file. The Beat and Bar Numbers are shown as the piece plays. You can pause the music by pressing the space bar and "rocking" the fast forward and rewind buttons, then pressing F2 (play) again. Really odd.

On the Level

ON THE LEFT of the Play/Record screen is a box containing five options which are activated by the function keys. Pressing + cycles through three more sets of options (the program calls these Levels). Let's see what we've got here.

F1 sends a file from the Record box to the Playback box. F3 toggles the Queued function which puts the sequencer under the control of external MIDI equipment (strange name). F5 lets you set the time signature and F7 toggles the metronome on and off (it plays through a separate audio out on the MIDIcard). F9 lets you punch time signatures, tempo and program changes into a file: the position is defined in beats.

On Level two, F1 accesses the Step Editor (coming up). F3 is an auto punch-in function allowing you to record a section inside a file. F5 toggles the Master control on and off which puts the sequencer under timing control of the MIDIcard. F6 toggles Omni mode and F9 toggles looping on and off allowing you to playback or overdub a file continuously.

On Level three, F1 will trim empty beats from the beginning and end of a file while F3 and F5 add empty beats. F7 shows you where the Marks are and F9 lets you set up to 16 Marks in a file. These are inserted in real time as the file plays back. Pressing "M" advances you to the next Marked position.

At Level four, F1 Cuts, Blanks and Copies segments from a file: the segment must be defined in terms of beats. F3 is the Paste function and F5 adjusts the metronome volume. F7 lets you chain up to ten files together, allowing you to specify leader beats and the number of repeats. Adjacent files can be made to play simultaneously and you can even perform an overdub. The flexibility of this process allows you to construct songs based on patterns as well as linear, tape-like constructions.

As you may have gathered, all positions within a file are referred to in terms of beats and some reference to bars (or Measures as the program calls them) would have been helpful.

Step Edit screen

Step Editor

THE STEP EDITOR loads a part of a file from disk into RAM for editing; the buffer size is variable allowing you to compensate for very dense files. Again, the segment of the file is specified in beats and it may take up to 40 seconds to load.

You can adjust the magnification of the Step window to show one, two or four beats surrounding the current note. There are two Step Edit displays. The first shows only one note and the second shows notes across an octave range with the note names by the left. If simultaneous notes are more than an octave apart the editor toggles between them as you step through it; not an ideal situation.

Both displays show a keyboard at the bottom of the screen with the current note highlighted (it would be nice if it showed middle C).

The layout looks like it could be the forerunner of grid-based editing, but it has no grid and the information is not as easily assimilated.

You can edit virtually any aspect of the music here. You can alter a note's position, duration, velocity, pitch and MIDI channel. You can add and delete notes and insert MIDI events, although the program expects them in hex. Who's it kidding? Most modem sequencers list the options in English - program change, pitch bend, even System Exclusive messages.

The cursor can be moved from note-to-note or from step-to-step (you can vary the step size) and you can change notes by playing them on your MIDI keyboard. Positions are given in dock pulses and beat numbers. Where are the bars?

Step-time Recording

TO RECORD IN step-time you must first "record" a blank file of the required length. Then select a step value and press "R" to go into step-time record. Each note you play will take the value of the step and you can enter chords by holding down several notes at once.

You can program notes on your MIDI keyboard to alter the step size so pressing them will advance the cursor by an eighth- or quarter-note, for example. By using a few carefully-chosen durations you'll be able to enter most types of music without too much trouble but again, the display is in beats only, not bars.

During recording and editing I got a "Can't open Playback file" error but renaming the file solved the problem.


THE FILTER SCREEN has five options: Auto-correct, Velocity Control, Channel Management, Transposition and Slide. A Source file is selected along with a filter operation and a target file must be named. That way you keep your original data intact. You can set start and end beat markers so you needn't filter the whole file.

There are lots of options within each filter process. There are three levels of Auto-correction, for example: note on only, simple auto-correct (for use with drum tracks) and MaxAuto which quantises both note on and off messages. There's also a swing option which is defined as a percentage.

The Velocity Filter lets you adjust the upper and lower dynamic range and the amount of gain.

Channel Management lets you record, extract or remove a range of pitches and MIDI messages from a channel. Here you can set a file to play on a particular MIDI channel. The process is rather circumlocutory, however: having entered the Filter menu you must select the file, enter a target filename, select Channel Management from the Filter menu, set the options and then filter. Whew (or similar comicbook expression of exhaustion).

The Transpositions Filter lets you run your piece through harmonic and melodic scale transpositions as well as just shifting it up and down. Slide lets you move a file back or forward in clock ticks.

Beware of hitting Escape to get you out of the Filter Screen as this will save the processed file without any warning.

Other Screens

THE MIXER SCREEN offers an alternative to the program's auto Listen function and lets you mix up to six files. A new file is created so you don't lose your original data.

The File Maintenance screen is where you change directories, rename, copy, delete and append files. You can't append a file directly to itself although you can append it to a "blank" file up to 100 times (disk space permitting).

The system sometimes generates temporary files and you can rename or delete them. There's no way to tell how long a file is without loading it.

The MIDI Channel screen allows you to select MIDI record channels and MIDI Thru channels so, for example, you can route what you play on your Master Keyboard to an expander.


THE MIDICARD HAS sync-to-tape input and output sockets and in Remote mode it can interface with SMPTE equipment via a SMPTE-to-MIDI converter.

The manual tells you how to set up dump and load messages to send and load voice banks to and from your equipment, but you need to be able to send those requests to Promidi via your equipment in the first place.

SDA have just released Midicard+ (£65), a plug-in platform for MIDIcard to give it compatibility with Roland MPU401-based software. They are also providing a number of file-conversion programs to allow Promidi files to be read by other PC software and they are working on the standard MIDI File Format.


WELL, PROMIDI HAS power but I'm afraid, for me, it could fare a lot better in the ease-of-use department. There are a few shortcuts but most operations require you to button-push your way through a series of menus and options, and some of the operations aren't particularly user-friendly. This is partly a result of recording direct to disk but the design must also share some of the responsibility.

Music software has developed enormously over the past couple of years. Most good programs nowadays fall under your fingers after a short period of use, and while Promidi may have been state-of-the-art in 1985 (when it was first launched), I could find little in it that was instinctive or intuitive. It has a very long learning curve and I think in 1988 musicians expect something more immediately accessible.

Promidi has three things going for it: the ability to create an unbelievably long piece of music (provided you have a hard disk) with an unlimited track length and a unlimited number of tracks. In addition, the distributors, MIDI Music, offer a free helpline service to Promidi owners. The importance of customer service in this business should never be underestimated.

If this appeals to you then take a look at Promidi by all means, but be prepared to spend a long time getting to know it.

Prices Promidi £399 including VAT; Demo disk £2.

(Contact Details)

Also featuring gear in this article

Previous Article in this issue

The Secrets of Timbre

Next article in this issue

FM 4-Operator Editors

Music Technology - Copyright: Music Maker Publications (UK), Future Publishing.


Music Technology - Jul 1988

Review by Ian Waugh

Previous article in this issue:

> The Secrets of Timbre

Next article in this issue:

> FM 4-Operator Editors

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