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~ Running MAX/FTS for NeXTStep in an emulator

The aptly named emulator Previous allows you to emulate NeXT hardware on modern platforms. It allows you to run NeXTStep and run software made for this environment. I have prepared a downloadable disk image for this emulator to experiment with an early version of MAX, a visual programming environment for music applications.

I am interested in the early days of MAX an influential visual programming environment geared towards music applications. This software originated at IRCAM and an early version was build for the NeXTcube and required a specialized soundcard (ISPW). I have been lucky to have been able to restore a NeXTCube with an ISPW soundcard but this hardware is extremely rare.

A functioning NeXTcube is already a rare collectors item and the ISPW soundcard is even more uncommon. The card was developed at IRCAM and later commercialised by Ariel Inc. which brought it to market right when NeXT announced to phase out hardware production. Overnight, the market for NeXT peripheral hardware collapsed and nobody wanted to buy an expensive soundcard for an obsolete hardware platform. The soundcard was never mass-produced: there are only the prototype boards made at IRCAM and a few batches of the commercial version. The total number ISPW soundcards must have been around a few dozen worldwide, in 1992. Now, over 30 years later, it is virtually impossible to find an ISPW card. Running an early version of MAX on original hardware is nearly impossible.


Fig: MAX 0.25 running in the Previous emulator on a modern MacOS system.

To make experiencing an early version of MAX more accessible I have prepared a disk image for the Previous emulator. The emulator emulates several NeXT machines and lets you run NeXT software on modern machines. The disc image uses NeXTStep 3.3 for OS and has MAX 0.25 pre-installed. Several NeXT machines can be emulated by Previous but, crucially for MAX, the ISPW soundcard is not emulated. This puts a severe limitation on MAX: there is no audio or MIDI input or output. However, you can start MAX in simulation mode and experience the patcher and see the original documentation and have a feel for the original supplied patches and follow the logic of patches.

To run MAX, download the disc image with NeXTStep and MAX [about 100MB]. By downloading this material you agree to use it only for academic, educational, historic or documentary use and not for commercial or other purposes. The zip-file also contains some information on how to get started and boot the system. Note that it has only been tested on an M1 mac.

For some more context please listen to Philippe Manoury on ‘Informatique musicale’ for insights into the ISPW at IRCAM. Read “Steve Jobs & the Next Big Thing (1993)” by Randall E. Stross which paints the commercially bleak history of NeXT and the (managereal, commercial, emotional) incompetence of Steve Jobs. It complements the “Steve Jobs (2011)” biography by Walter Isaacson nicely. Also see Electronic Music and the NeXTcube – Running MAX on the IRCAM Musical Workstation and USB MIDI interface for the NeXTCube – ISPW board


~ USB MIDI interface for the NeXTCube - ISPW board

I have recently restored a NeXTCube with an ISPW Ariel soundcard with the aim to put it in the hands of artists and researchers in the context of a living electronic music instrument heritage project. To make the cube talk to keyboards, synths or other audio workstations I have built a MIDI interface for the NeXTcube.


Fig: the NeXTCube with the Ariel ProPort and MIDI input/output interface.

Recently, I was able to restore a NeXTCube and install an early version of MAX – a graphical music programming environment. However, a crucial part of the system was missing: there was no way to do MIDI input/output. MIDI is used to connect controllers, keyboards, synthesizers or other musical instruments to the audio workstation. The NeXTCube itself has a serial port which allows users to connect MIDI devices. Next to the serial port on the mainboard, the NeXTCube I am working with also has a RS-422 serial port on the ISPW ‘soundcard’. The serial port uses RS-422 and mini DIN 8 connectors which provide MIDI input and output. While the MIDI data bytes are transmitted according to spec, the connector and the electrical signals are not compatible with standard MIDI.


Fig: the IRCAM/Ariel ISPW soundcard with mini DIN-8 RS-433 serial port on the right.

For MIDI I/O we need a device which allows to connect the RS-422 MIDI to both legacy MIDI devices and to computers via USB MIDI. If a MIDI event arrives from the NeXTCube’s RS-422 it needs to be passed through to the USB and legacy MIDI ports and the other way around. The Teensy platform is ideal: it supports hardware serial and USB MIDI. In this retro-computing project, it seems wasteful to use the 600MHz Teensy 4.0 only for message passing: the Teensy has much more computing power than NeXTcube but it is cheap, easy to program, available and practical.

The RS-422 serial port uses -6V to 6V logic which needs to be transformed to the 0V to 3.3V logic for the Teensy microcontroller. A PCB provides this capability and is connected to a hardware serial port of the Teensy. The pinout of the RS-422 port was measured via a scope and matched the documentation. The Teensy has an usbMIDI mode and can present itself as a standard MIDI device to a PC. Two opto-isolated legacy MIDI DIN-5 ports were connected to another hardware serial port. The software on the Teensy conducts the three-way MIDI message passing.

Vid: Max/FTS FM synth reacting to USB MIDI input.

The electronics were fixed into a reused metal enclosure. The front panel of the enclosure was replaced by a custom 3D printed panel. The front contains the RS-422 port, two MIDI DIN 5 ports and a micro usb port either for power alone or MIDI messages and power. Feel free to check out the OpenSCAD design with a level MINI DIN8 hole.

With a working MIDI interface for the NeXTcube allows interfacing with MIDI keyboards and controllers. It can also be used to measure roundtrip latency. MIDI to sound latency determines how long it takes between pressing a MIDI key and hearing sound. MIDI to MIDI roundtrip latency determines how long it takes to process, parse and return a MIDI message. For a responsive, reliable system both types of latencies should be constant and preferably in the range of 10ms or below.


Fig: Measured MIDI roundtrip latency on the ISPW board for the NeXTCube.

Measuring the MIDI roundtrip latency shows that the system is able to respond in 3.6+-0.4 ms (N=300). A combination of a MAX patch and Teensy firmware was used to measure this automatically. The MIDI-to-audio latency was measured a few times manually and always was around 13ms. These figures show that the system is ideal for low-latency real-time music making in its default configuration. In MAX the audio buffer sizes could be reduced to achieve an even lower latency but with the risk of running into buffer underruns and audio glitches.

Small discussion the USB MIDI interface for the NeXTCube on Hackaday


~ Electronic Music and the NeXTcube - Running MAX on the IRCAM Musical Workstation

The NeXTcube is an influential machine in computing history. The NeXTcube, with an additional soundcard, was also one of the first off-the-shelf devices for high-quality, real-time music applications. I have restored a NeXTcube to run an early version of MAX, an environment for interactive music applications.

The NeXTcube context and the IRCAM Musical Workstation

In 1990 NeXT started selling the NeXTcube, a high-end workstation. It introduced or brought together many concepts (objective-c, the Mach kernel, postscript, an app store) which are still in use today. The NeXTcube’s influence is especially felt in the Apple ecosystem with Mac OS X, iPhones and iPads being direct decedents of NeXT’s line of computers.

Due to its high price, the NeXTcube was not a commercial success. It mainly ended up at companies or in the hands of researchers. Two of those researchers, Tim Berners-Lee and Robert Cailliau created the first http server and web browser at CERN on a NeXTcube. Coincidently, the http software was publicly released exactly 30 years ago today. Famously, the cube was also used to develop games like the original Doom and Quake. So yes, the NeXTcube runs Doom.


Fig: the NeXTcube’s design stood out compared to the contemporary beige box PCs.

Less well known is the fact that the NeXTcube is also one of the first computing devices capable enough for real-time, high-quality interactive music applications. In the mid 1980s this was still a dream at IRCAM, a French research institute with the aim to ‘contribute to the renewal of musical expression through science and technology’. The bespoke hardware and software systems for music applications from the mid 80s were further developed and commercialised in the early 90s. Together these developments resulted in a commercially available version of the “IRCAM Musical Workstation (IMW)”, an early, if not the first, off-the-shelf computer for interactive music applications.

The IRCAM Musical Workstation (IMW), sometimes called the IRCAM Signal Processing Workstation (ISPW), consisted of several hard and software modules working together to enable interactive music applications. An important component was a ‘soundcard’ which had two beefy 40MHz i860 intel CPUs for DSP. When installed in the NeXTcube, the soundcard had more computing power than the rest of the computer. This is similar to modern computers where some graphics cards have more raw computing power than the main CPU. The soundcard was developed at IRCAM and commercialized by Ariel inc. under the name “Ariel ProPort”.


The IRCAM Ariel DSP coprocessor, soundcard.

A few software environments were developed at IRCAM which made use of the new hardware. One was Animal, another, was the much more influential MAX. MAX provides a graphical programming environment specific for music applications. Descendants of MAX are still used today, see Ableton Max for Live and Pure Data. I consider the introduction of MAX as a pivotal point in electronic music history. Up until the introduction of MAX, creating a new electronic music instrument meant bespoke hardware development. With MAX, this is done purely in software. This made electronic sound or instrument design not only faster but also accessible to a much wider audience of composers, artists and thinkerers.

The NeXTcube at IPEM

IPEM was an early electronic music production studio embedded at Ghent University, Belgium. Now it is active as a internationally acclaimed research center for interdisciplinary music research. In the early 90s IPEM acquired a NeXTcube Turbo with an internal diskette drive, SCSI hard disk, NextDimension color graphics card and an Ariel ProPort DSP/ISPW module. The cube was preserved well and came with many of the original software, books and manuals. I have been trying to get this machine working and configure it as an “IRCAM Musical Workstation”.


IPEM’s NeXTcube with IRCAM Ariel ProPort.

There were a few practical issues: the mouse was broken, the hard drive unreliable and the main system fan loud and full of dust. The mouse had a broken cable which was fixed, the hard drive was replaced by a SCSI2SD setup and the fan was replaced with a new one. On the software side of things, the Internet Archive hosts NeXTStep 3.3 which, after many attempts, was installed on the cube. Unfortunately there seemed to be a compatibility issue. The Ariel ProPort kernel module did not work. I started over installed NeXTStep 3.1, with the same result. Finally, I installed NeXTStep 3.0 which was compatible with the kernel module and MAX/FTS!

Vid: Max/FTS with a commercial Ariel soundcard running on a NeXTcube Turbo.

The restoration of the IRCAM Signal Processing Workstation instruments fits in a university project on living heritage The idea is to get key historic electronic music instruments into the hands of researchers and artists to pull the fading knowledge on these devices back into a living culture of interaction. This idea already resulted in an album: DEEWEE Sessions vol. 01. Currently the collection includes a 1960s reverb plate, an EMS Synti 100 analog synthesizer from the 70s, a Yamaha DX7 (80s) and finally the NeXTCube/ISPW represents the early 90s and the departure of physical instruments to immaterial software based systems.

Acknowledgements & Further reading

This project was made possible with the support of the Belgian Music Instrument Museum and IPEM, Ghent University. I was fortunate to get assistance by Ivan Schepers and Marc Leman at IPEM but also by the main developers of MAX: Miller Puckette. I would also like to thank Anthony Agnello formerly at Ariel Corp for additional image material and info. I also found the WinWorld and NeXTComputers communities and resources extremely helpful. Thanks a lot!


See also the discussion on this article at Hacker News
Lindemann, E., Dechelle, F., Smith, B., & Starkier, M. (1991). The Architecture of the IRCAM Musical Workstation – Computer Music Journal, 15(3), 41–49.
Puckette, M. (1991). FTS: A Real-Time Monitor for Multiprocessor Music Synthesis. Computer Music Journal, 15(3), 58–67.
Puckette, M. 1988. The Patcher, Proceedings, ICMC. San Francisco: International Computer Music Association, pp. 420-429.
Puckette, M. 1991. Combining Event and Signal Processing in the MAX Graphical Programming Environment. Computer Music Journal 15(3): 68-77.