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Jen Musipack 1.0

David Ellis and the sad tale of an Italian computer music add-on that bears more than a passing resemblance to established designs from the States.

The Musipack is the first micro-based musical add-on package of European origin to reach these shores. In common with its counterparts from across the Atlantic, it works with any Apple-compatible computer but, as David Ellis discovered, the similarities don't end there...

Jen aren't the sort of company that you'd expect to come out with anything of a hotly contentious nature. After all, they've carved themselves a nice little niche in the area of low-cost monophonic synths, electronic pianos, and organs. The trouble, of course, is that the microprocessor revolution has signalled a make or break situation for such companies, and what used to be considered a 'safe' product has been ousted in favour of the higher-tech polyphonic synth with programmability, sequencing, LCD displays, and the MIDI.

Jen have been fairly astute in recognising that the sensible replacement of the electronic piano of old is the keyboard and sound synthesis add-on to the personal computer. Provided the hardware delivers the goods, the system can be upgraded simply by running it with new software: the logic of that philosophy has been amply demonstrated by two other companies predating Jen's entrance into the micro add-on arena - Syntauri and Passport Designs, makers of the alphaSyntauri and Soundchaser systems respectively.

Both of the American systems use the Apple II or IIe for the processing side of their action, together with four or five octave keyboards of their own design that plug into the Apple via an interface card, and the Mountain Computer MusicSystem digital synthesiser boards that get fed with musical instructions and waveforms from the micro's motherboard. Jen, on the other hand, have elected to go for supplying their own micro, keyboard, and synthesiser boards. Highly laudable, you might think.

Well, not quite. The micro, called the Lemon II, is an Apple II lookalike that adds little to its sweeter predecessor other than a numeric keypad, a feature which is hardly of momentous import to musical applications of micros. Talking of 'import', it's highly unlikely that the Lemon will ever appear in this country, as Apple's busy band of lawyers have served an injunction on the manufacturer of the Lemon II. So, the fact that the Musipack can be run on 'any Apple-compatible computer' is rather fortunate for Jen.

However, the lookalike factor goes a good deal further than the micro. The Jen synthesiser boards (called the DSG10) are actually exact replicas of the Mountain Computer Cards - right down to the layout of tracks, identity of ICs (though numbers have been scrubbed off in a vain attempt to divert overeager scrutiny), and value of components. Very curious.

Now, bearing in mind that the Mountain Computer boards are five years old and showing their age, you'd have thought that Jen would have taken the opportunity to improve on the original. Not a bit of it. They're still on the noisy side, rather deficient at the top end, and lacking in punch. Ironically, Passport Designs, the other company to enter into Jen's frame of reference (so to speak), have actually re-designed Mountain Computer's synthesiser boards onto just one card (the MX5 - with Mountain Computer's blessing, of course), giving improved bandwidth, reduced crosstalk, and an onboard keyboard interface and drum sync to boot.

And Jen's own IKB10 keyboard interface? Well, surprise, surprise, it's a direct copy of the interface card that Passport Designs produced for their earlier Soundchaser system. At least the five-octave KBD10 keyboard looks a little different to the Soundchaser (it's five octaves rather than four), though that woodwork and case style does look a little familiar...


According to the Musipack manual, this was 'conceived by the Edgar Varese Studio of Computational Sonology, Pescara', and the one (partly) listable program on the software disk informs us that one Piero de Berardinis owns the copyright on it.

The opening pages of the manual introduce the user to one original feature of Musipack - that of a disk-operating system that date-stamps the disk. Personally, I find this of more annoyance than value - date-stamped disks get a little wearisome when you're copying from one disk to another. Like the rest of the Musipack's operations, the opening pages of the software are menu-driven. That on booting-up includes an option marked 'E>nd'. Keying this displays the message, 'end pack (y/n)?'

Keying 'D>igitrack', on the other hand, loads up and runs the various routines needed to get the keyboard inputting notes and the synthesiser boards outputting sounds. Like most menu options, this takes time (getting on for two minutes, in fact), and you're then greeted by a further menu. '1' puts you and 'Gestast' (whatever that is) into the picture by providing a display of all the parameters that make up each of the ten instruments loaded into the memory. The keyboard also becomes active at the same time.


The way the software operates is to configure two of the 16 oscillators on the synthesiser boards for each note played on the keyboard. These come in pairs of eight, one set going to the left output and the other to the right. The nearest traditional equivalent to these oscillators is the type of DCO found in the OSCar or PPG Wave. That's because they're waveform-programmable, courtesy of a continuous stream of numbers from appropriate waveform tables in the computer's memory, with one chosen waveform going to the first oscillator and another to the second.

However, unlike the OSCar and PPG Wave 2.3, there aren't any VCFs to play around with on the Jen, so the only modification to the sound of raw waveforms is envelope shaping (the ADSR parameters shown for each oscillator) and LFO modulation (the FREMOD parameters shown underneath). The nice thing about the LFO is that each of the ten instruments can have their own waveform (which can be anything you like as opposed to the usual sine, square, sawtooth, etc.), and different modulation levels can be assigned to the two oscillators. So, by putting the right parameters in the right places, you can get delayed vibrato, reversed vibrato, and a whole host of other modulation possibilities.

As the display indicates, these parameters appear as hexadecimal values (counting 0 through F), so a maximum value appears as FF rather than 255. Not very friendly, really. I mean, would you buy a keyboard that told you via its LCD that you'd just punched up preset number 7F? So why, then, have Jen insisted on using hex values when there's ample space in the display for normal base 10 values? Well, this is where the lookalike story re-surfaces. It just so happens that Passport's Soundchaser also uses hexadecimal for its representation of parameter values, though this time for the good reason of wanting to squash a lot of data into a small space. However, the similarity between the two systems goes a good deal deeper than that. In fact, all the parameter names for the ADSRs, LFO, volume and octave settings show a remarkable degree of concordance between the Jen Musipack and Soundchaser. To cap it all, the Musipack software turned out to be perfectly happy running my Mountain Computer boards rather than Jen's own lookalikes - even when using the Soundchaser keyboard instead of the Jen variety. Indeed, with the same preset parameters on-screen, there was actually no difference between what the two systems were doing and what sounds emerged.


More fuel was added to my suspicions when I looked at the sequencing side of the Musipack software. To get into this from the preset display, you simply key the Escape button and a different display materialises. The sequencer works in either of two ways. First, as a one-pass polyphonic sequencer of 4400 notes (the 'Mono' mode); and second, as a four-track sequencer with space for 1100 notes per track (the 'Track' mode). Recording is accomplished by keying in the track number you want to record onto ('R' for Record), and pressing the space bar to start. At the end of recording, the space bar is pressed again, and keying in the same track number and 'P' (for Play) provides the proof of the playful pudding. To record on the other tracks, you simply play along with the first whilst recording on another, and the whole lot should be in sync on playback. Then, with all the notes in place, you can start assigning different preset instruments to each of the tracks: you can even go back to the preset display to change parameters in real time as it's playing.

I say the tracks 'should be in sync' because one slight problem is encountered if you try changing the playback speed (with the left and right cursor keys on the computer) whilst it's doing its thing - namely that it gets out of sync. Hmm, that rings a bell. Strange that that was also one of the bugs in the Soundchaser software. Come to think of it, the entire sequencer has a more than faint resemblance to Passport's offspring - even down to the 'bleep' that accompanies the pressing of the space bar.

Taking a four-track sequencer note file (BOP.TRAKS) that I'd created with the Sondchaser sequencer, altering it to meet the disk filing conventions of Musipack (to SYST.BOP), and then loading it into the Apple for playback by the Jen 'Digitrack' sequencer demonstrated that there was actually no earthly difference between the two. In other words, it would seem that the sequencer side of the Musipack software has also been purloined from Passport Designs.


The final part of the Musipack software concerns the actual construction of waveforms for consumption by the 16 digital oscillators. Thankfully, the 'Spectre' program does apear to contain a vestige of original programming. The lazy way of constructing waveforms is to ask the user to input harmonic numbers with relative amplitudes and then let the computer generate a 256-byte waveform table from the data - the approach taken by both Passport and Syntauri with their systems. However, a fact of life is that the harmonics constituting a complex waveform don't always tow the line when it comes to digging their feet in at the starting grid. Putting this into a mathematical perspective, the best sort of waveform synthesis needs to consider not only the number and amplitude of each harmonic but also its phase, ie. where it starts off from zero amplitude in relation to its neighbours. Unfortunately, this takes time, and entering values for all 24 possible harmonics occupies four minutes of computer (and user) time before they can be displayed and auditioned. Still, this is a step in the right direction. The other side of the coin is the 'Grafond' program, a draw-your-waveform-with-game-paddles approach. This is familiar Soundchaser territory, and there's nothing in Jen's implementation that even hints at originality.


By now, you may be wondering what the hell is going on. Frankly, so am I.

It's quite clear what's been going on in the Edgar Varese Studio. The original Soundchaser software comprised a machine code program for scanning the keyboard and running the synthesiser hardware, plus a BASIC program for setting up screen displays and interacting with the user. The bald fact of the matter is that Jen's machine code routines are identical to Passport's. The BASIC program, on the other hand, has been taken apart to make up the various separate Musipack programs, altered to suit Jen's own display requirements, and then compiled into machine code - effectively hiding all of Passport's original work from all but those with a penchant for machine code.

If this reads like a detective story, I'm hardly surprised. The unnerving point is that Jen have infringed copyright in four areas - the computer itself, the synthesiser boards, the keyboard interface, and the software. Unlike the reviewer in another magazine with a not altogether dissimilar acronym to E&MM, I don't feel that it's responsible journalism to write about something in glowing terms if it owes its existence to plagiarism on such a grand scale.

Unfortunately, things are unlikely to stop here. Jen have promised future updates along the lines of 16-track sequencing with drum sync and a music transcribing option. Passport also produce a 16-track sequencer with drum sync (Turbo Traks - reviewed in E&MM November 83) and a music transcriber (Notewriter).

What more can I say?

Prices and availability: the Jen Musipack 1-0 is distributed in the UK by British Music Strings, (Contact Details), and the £900 price tag includes the KBD10 five-octave keyboard, IKB10 interface card, DSG10 synthesiser boards, and 1.0 software.

Also featuring gear in this article

Jen Musipack 1.0
(ES May 84)

Browse category: Software: Synth > Jen

Previous Article in this issue

Boss DD2 Digital Delay Pedal

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MFB Digital Drum Machine

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


Electronics & Music Maker - Jun 1984

Gear in this article:

Software: Synth > Jen > Musipack 1.0

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Apple II Platform

Review by David Ellis

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> Boss DD2 Digital Delay Pedal...

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