JJazzlab installation under Linux

Just enter a few chords and get a backing band to practice? Try JJazzlab. These short instructions describe how to get a permanent MIDI connection device under Linux.

  • Unpack the archive to a location with write privileges if you like (JJazzlab can apply updates itself)
  • Add the following line to /etc/modules:
  • Create the file /etc/modprobe.d/snd-virmidi_options.conf with the content:
    options snd-virmidi midi_devs=1
  • Reboot
  • Start JJazzlab
  • Under options configure JJazzlab to use “VirMIDI” as MIDI out

  • You can now use the output “Virtual Raw MIDI 0-0 16: VirMIDI 0-0″ to connect a soundfont / synthesizer

Squid / Privoxy for the impatient

Do you need a caching proxy which blocks tracking and advertising for your whole network? Here’s a quick start guide:

Install Squid and Privoxy:

sudo apt install squid privoxy

Add the following lines to /etc/squid.conf with:

# Allow access for whole network
http_access allow localnet

# Privoxy start
# Forward request to Privoxy
cache_peer localhost parent 8118 7 no-query default no-digest no-netdb-exchange

# ACL for FTP
acl ftp proto FTP

# No FTP through Privoxy
always_direct allow ftp

# Use Privoxy, if available
prefer_direct off
nonhierarchical_direct off
# Privoxy end

# Immediate restart
shutdown_lifetime 0 seconds

Restart Squid to activate the changes. On all Clients, configure http://PROXY-IP:3128 as a proxy.

Yamaha MODX, Linux and DAW-Integration


  • Use MIDI Port 1 for transmission of notes, controllers and time syncing
  • Use MIDI Port 2 as a control port to connect a DAW (MODX acts as a Mackie Control Unit)
  • If possible, select a Mackie Control Unit as a controller using MIDI port 2
  • Set MODX settings for Performance/Remote to (Ableton) ‘Live’ (Works best for MIDI learning functions)

DAW Remote functions

Transport Control Mode

Works as expected

Track Control Mode

The four turning knobs above the sliders do not send values from 0 to 127, try to configure a Mackie Control unit, if possible

Plugin Control Mode

Works as expected

DAW configurations


  • Choose a “Mackie Control Unit” as a Controller, connect it with MIDI port 2

Tracktion Waveform

  • Choose a “Mackie Control Unit” as a Controller, connect it with MIDI port 2


  • Set MODX settings for Performance/Remote to ‘Live’ (Works best for MIDI learning functions)
  • Activate “Dedicated Control Port” under View/Options
  • Connect MODX MIDI 1 with Qtractor
  • Connect MODX MIDI 2 with Qtractor’s control port
  • Teach shortcuts to Qtractor
  • Remove “Latch” option from shortcuts for buttons

Midi learning

  • Configure MIDI Elements under “View/Controllers”
  • Configure sliders with “Logarithmic” option
  • Learning MIDI commands for Transport control

The Yamaha MODX Music Synthesizer and Linux


The Yamaha MODX Music Synthesizer has a builtin class compliant audio interface which works out of the box under Linux. The audio capabilities are:

  • Sampling rate: 44100hz (fixed)
  • Analog outputs: 10
  • Analog inputs: 4
  • MIDI inputs/outputs: 3
All inputs and outputs can be used

Jack settings

Only with the Jack audio system all 10 outputs and 4 inputs can be used with the following settings:

  • Sampling rate: 44100 (fixed)
  • Frames: 512 / 256 / 128 / 64 / 32 / 16 (the lower the better for latency)
  • Buffer: 3 / 2 (the lower the better for latency)


The MODX comes with four MIDI templates for proprietary DAWs, there are three MIDI inputs/outputs:

  • 1: Contains notes, controllers and time syncing
  • 2: Should be used as a control port to connect a DAW (to a Mackie Control Unit)
  • 3: Reserved for future use?

DAW Integration

DAW integration has moved here.

Using the Univention Corporate Server with single email addresses and Postfix

Email for small setups with Postfix

A lot of system services rely on email or integrate this service. To use the Univention infrastructure with single email addresses, the following postfix configuration can be used.These instructions describe a setup for three freemail accounts using two different providers. Do not enter the freemail domains in UCS as a mail domain.

First install the following apps using the app center:

  • Fetchmail
  • Kopano Core (or another groupware)
  • Kopano Webapp
  • Kopano Z-Push

Receiving emails

Add the three user accounts using the UMC, enter the freemail address as the primary e-mail account. Configure fetchmail by opening the extended configuration from all the three user accounts. Send an e-mail from external clients to these accounts and wait up to 20 minutes until the e-mails appear in Kopano.

Sending emails

Add the following lines to /etc/postfix/main.cf.local (not main.cf):

sender_dependent_relayhost_maps = hash:/etc/postfix/relaymap
smtp_sender_dependent_authentication = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwords
smtp_sasl_security_options = noanonymous
transport_maps = hash:/etc/postfix/transport

Activate changes:

ucr commit /etc/postfix/main.cf

Define freemailer smtp relays, create the file /etc/postfix/relaymap

@freemail1.de smtp.freemail1.de
@freemail2.de smtp.freemail2.de

Create hashfile:

postmap /etc/postfix/relaymap

Now configure the passwords for sending e-mails for every account, create the file /etc/postfix/sasl_passwords

user1@freemail1.de user1@freemail1.de:User1MailPassword
user2@freemail1.de user2@freemail1.de:User2MailPassword
user3@freemail2.de user3@freemail2.de:User3MailPassword

Create hashfile and restart postfix:

postmap /etc/postfix/sasl_passwords
service postfix restart
Local delivery

At this point Kopano webmail can be used to send e-mails from one account to another, but every mail is sent to and fetched from the freemail provider. To ensure that local accounts communicate only using the UCS add the following:

Add to /etc/univention/templates/files/etc/postfix/transport.d/10_base

user1@freemail1.de lmtp:
user2@freemail1.de lmtp:
user3@freemail2.de lmtp:

Activate changes with:

ucr commit /etc/postfix/transport
service postfix restart

The Univention Corporate Server (UCS)

UCS as a Server infrastructure

The Univention Corporate Server (UCS) based on Linux allows the central administration of users, systems and services for small, medium and huge infrastructures. The Core Edition can be used for free, a lot of popular and complex software solutions like groupware or office services can be installed easily using a web frontend.

User and access management

every user account is managed through a web interface, Univention realised the management of 30 million users for one customer.


The Univention infrastructure provides a lot of network services, hardware integration and administration frontends.


  • Installing Univention in a virtual machine allows creating backups/snapshots of the whole system easily.
  • Many services integrate or rely on email as a service. Configuring email following the documentation is a good starting point. To use single email addresses without a registered domain, follow these instructions.

S.u.S.E. 4.4.1 – Linux in 1997

S.u.S.E. 4.4.1 can still be installed using a virtual machine (KVM/QEMU). Thanks to very old standard technologies like ‘PS/2’ and ‘VGA’ even the graphical desktop can be configured. The installation was quite complicated, but there was a manual containing over 500 pages of help. Installation requirements were 8MB of RAM for text based operations and 12MB for the X-Window system.

Live-System, floppy boot disc and two CDROM

The CDROM was not bootable, you had to use a floppy boot disk.YAST was used for installation and configuration:

YAST for configuration and administration

Linux already supported a lot of hardware:

List of supported graphic adapters

The graphical desktop had to be started using the command line with ‘startx’.

The X-Window system


The graphical interface has not changed that much. Vim and the Midnight Commander (mc) were already preinstalled.

Linux on a Fujitsu Siemens ESPRIMO Mobile D9510 from 2009

Fujitsu Siemens ESPRIMO Mobile D9510

Linux runs well on an old Laptop after installing a SSD. A quick test with Linux Mint Xfce 20.1 showed:

  • Boot (Grub) to login: 15 seconds
  • Login to desktop: 8 seconds

The left four of the five buttons on top of the keyboard beneath the power button do not work out of the box:

Buttons D9510

To enable these buttons permanently, enter:

sudo crontab -e

Append the line:

@reboot /usr/bin/setkeycodes e001 182 e002 183 e003 184 e004 185

Now these buttons can be used for starting programs or other shortcuts.

Thunderbird – More than an e-mail client

Thunderbird can be used for e-mails, appointments, notes, RSS-Feeds and much more.


Thunderbird recognizes the correct settings from many email providers. Just enter your email address and the correct password. The use of the IMAP protocol ensures that the emails stay on the providers servers. Benefits: emails can be sent using a file manager or an office suite, there is a full integration into the desktop


Lightning is an integrated component which handles calendars using the CalDAV protocol.

Address book / ActiveSync

Thunderbird itself has no CardDav support at the moment. You can install the TBSync plugin for CalDAV, CardDAV and
Exchange ActiveSync (EAS) support. Be sure to install the TBSync provider for the above protocols, too.

Debugging / Logging

Open a terminal and enter:

export NSPR_LOG_MODULES=all:5

This will enable the maximum debug output for all modules. Further informations for logging can be found on Mozillas Web Docs