Organ is a real-time program for full organ play at home, but also in smaller halls, parish rooms, smaller churches, etc. In opposite to comparable products, there are no special requirements to the hardware. A reference equipment runs with i486 and AWE32.
Organ supports the MIDIgital Organ Conception from Hoffrichter. It involves a complete play-table with full pedal and up to three manuals.
The MIDI control is done via a standardized interface. At present, Soundblaster MIDI is supported. All SoundblasterPro compatible cards contain it. Other interfaces need a documented driver.
The reference program runs under Linux. It is possible to port it to Windows, but it is not recommended for the worse time behaviour of Windows.

The sound synthesis is done via Soundfont. The Soundfont format allows the use of samples from "natural" patterns. With it, one can completely put the best instruments in Soundfont banks. The control parameters, e.g. loops or envelopes, particularly the always relevant Release, are optimized in the Soundfonts themselves, and it is not necessary to newly calculate them in real time. The size of the Soundfont banks is only few MB, that does not make problems in old computers too.
Well-tried hardware is the EMU8K synthesizer chip, that is on Creative's AWE32 and AWE64. The sound synthesis is done completely with this chip, so that the CPU keeps free for the remaining functions.
Newer computers run also with `fluidsynth', that is a software synthesizer for Soundfonts. With this, one becomes more independent on the hardware.

Additive mixture: This is done in the Soundfont itself on the one hand, but the organist can do it usual way on the other hand. An alternative stop operation via the claviers is available for it.
It is possible with the EMU8K to play up to 30 samples at the same time. The software synthesizer has no fixed limit.
Storing all adjusted combinations in macro files. These are always readable back.
Fine tuning easily to handle.
Support up to four keyboards (i.e. pedal and three manuals).
Real time record to a standard MIDI file is possible!

Masterkeyboard with channel switch, better a complete master equipment like the MDO system from Hoffrichter.
Loudspeaker and amplifier equipment according to the spatial circumstances. Connections for headphones are usually available.
Either an i486 with AWE32 or AWE64 -
or a Pentium from 1 GHz with MIDI interface (MPU401 with input or USB MIDI interface).
Preferred OS: Linux, for the old hardware with kernel 2.0.36.

Since Linux is a multi-tasking OS, standard implementations do not necessarily optimally run with music. The real-time behaviour can be clearly improved:
If old systems are exclusively used for music, the most simple and most effective measure consists in renaming the file /etc/crontab .
At least from SuSE 10.2, following entry in the file /etc/security/limits.conf helps:
* [Tab] - [Tab] nice [Tab] -10

The organ package contains approved versions of `Organ' as well as a compiled sound module for Linux 2.0.36 und AWE32/64 from old drivers by Takashi Iwai (with sources). On compilation &c. see music package.