Linux MIDI: a Brief History, Part 1
The OSS/Free kernel sound API supported the basic MIDI capabilities of the original SoundBlaster soundcards. This offered a maximum of 16 channels--no support for multiport interfaces--and support for hardware interfaces only in UART mode, also called dumb mode for its relatively simple capabilities. The OSS/Free API supported a raw MIDI device, /dev/midi, and an advanced device, /dev/sequencer, for interfaces controlling the timing of the MIDI data queue.
From kernel 2.6 onward, ALSA (the Advanced Linux Sound Architecture) is the kernel sound system. Among its many features, ALSA includes backwards-compatibility with OSS/Free MIDI support while offering new support for more modern MIDI systems, including a sequencer architecture that allows easy connections between ALSA sequencer clients and a module for creating virtual MIDI ports on machines without MIDI hardware--very handy on my laptop. ALSA's MIDI hardware support includes standalone MIDI cards, soundcard MIDI hardware connectors, serial and parallel port interfaces and USB MIDI interfaces. The system also installs some useful MIDI utilities, such as the aconnect sequencer client router, the amidi tool for sending and receiving raw MIDI data and the amidirecord utility for recording a standard MIDI file at the command prompt. Besides the OSS/Free /dev/midi and /dev/sequencer devices, ALSA adds its own /dev/snd/midiCxDx logical devices, where C is the card number and D is the device number.
The ALSA sequencer API is a most welcome evolution in Linux MIDI support. Compliant programs may be connected freely, with multiple inputs allowable on a single port. Graphic patch bays are available that display and edit the send/receive status of the available clients. Incidentally, ALSA's virmidi (virtual MIDI) ports appear to the system as though they are real ports, and their data may be routed to and from any other port, real or virtual.
I also must mention that Linux MIDI support extends to a number of operating system and CPU emulation environments, with especially good results achievable with DOSemu, an MS-DOS emulator, and XSteem, an AtariST emulator.
At the least, a complete software-based MIDI music-making environment should include a MIDI sequencer, a rhythm programmer and one or more software synthesizers. Serious MIDI musicians also should include helper applications, such as patch bays and MIDI event filters. Many interesting MIDI composition environments are available, including MIDI programming languages and GUI-based programs. Music notation programs especially have benefited from MIDI connectivity. Standard MIDI files are fairly easy to convert to notation, and your notated compositions can be rendered and performed easily by way of MIDI.
In Part 2, I will describe Linux programs and utilities in all of these categories. For now I leave you with some eye candy taken from the current Linux MIDI software scene. Enjoy!
Similis sum folio de quo ludunt venti.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- Stunnel Security for Oracle
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Managing Linux Using Puppet
- My +1 Sword of Productivity
- SUSE LLC's SUSE Manager
- Parsing an RSS News Feed with a Bash Script
- Doing for User Space What We Did for Kernel Space
- SuperTuxKart 0.9.2 Released
- Google's SwiftShader Released
- Non-Linux FOSS: Caffeine!
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide