1 = Left Channel Output                              2 = Ground (Connect the cable screens to this pin)                              3 = Left Channel Input                              4 = Right Channel Output                              5 = Right Channel Input i.e. pins 1 and 4 take the audio to the cassette, with screens to 2.   (Short pins 1&4 and 3&5 for mono) If your cassette deck uses stereo jack plugs then you will have the input plug connected to pins 3 and 5 with the screening on 2.

MIDI Interface

The functionality of the connectors is:

MIDI OUT                Midi Data Output

MIDI IN                    Midi Data Input

MIDI THRU              Mirrors data at the INPUT

Note:  The purpose of MIDI THRU is to enable (Daisy Chaining) of the MIDI data

There is no limit physically to the number of devices one could chain, but as this is serial data, each MIDI THRU connection adds an amount of delay that could become significant.  In this case it is better to use a MIDI distribution unit where one INPUT fans out to a number of OUTPUTS.

Connections.        Data connection is simple as the data only uses two pins of a standard 5-pin DIN connector.  Unlike the audio cable the ground connection is only included to ground the screen. This is an electrostatic function and as such it should only be connected at one end of the cable to prevent earth loops.

Do not forget to connect up the audio, for details of which you should refer to my AUDIO connections section.

MIDI interface cables are quite readily purchased off the shelf in most parts of the world, probably at a much cheaper price than one could build them oneself.  It would however not be correct for me not to include a description of typical connections.  For these the most likely requirement are to connect ones WERSI instrument up to an expander, or to a PC or MAC.  Included below are diagrams to show connections and pin-outs for both organ to an expander or organ to the Joystick port of a “Creative Labs” compatible “SoundBlaster” PC card.  If the PC interface card does not include a proper MIDI interface (i.e. with opto-isolator on the PC card) then additional components need to be included in the cabling. 

For MIDI the physical connection is the easy part, the MIDI protocols or IRQ and DMA conflicts that may occur on connection to a PC are beyond the scope of this article and well covered on other web sites.

RS232 Interface

1. Requirements

   To interface an organ to a PC, providing it has an RS232 interface, are as follows:-

   • To physically connect the RS232 port on the organ to a serial port on the PC via a "null modem".

   • Applications software on the PC to send and receive data on the serial port.

   • Set up protocols on the Organ and PC to match.

   • Transfer the data to a PC file which may be e-mailed to myself or other interested WERSI enthusiasts.

2. Hardware connection

   The RS232 connection can be up to a distance of 10 metres or so. It is not necessary therefore for the PC to be adjacant. If you are able to make your own lead then a single cable connection configured as a null modem will suffice. Purchasing ready made it may be necessary to buy a single straight RS232 cable with a seperate "null modem" attatchment at one end. Below I have shown the most common connection which assumes a 9 pin "D-connector" serial port connection on the PC and a 25 pin "D-connector" on the organ.

   Service	PC 9 pin Socket	Organ 25 pin Plug
   TxD Data from PC	2	2
   RxD Data to PC	3	3
   Data Ground	5	7
   RTS	9	20

3. Application Software

   This is software required both in the organ and the PC to carry out the data transfer. It should be noted here that most communications software for PC's is too "clever" for our requirements here. Data transfer is normally to recognised data transfer protocols such as XMODEM or KERMIT, this enables the software to check for corruptions when the data is carried via modems on noisy lines. It also enables the software to check when the data transfer is complete. The organ has no such protocols so it must be possible to copy raw data files, these are sometimes referred to as "binary". ASCII Text is not suitable. I have been using "Procom plus" this has a useful facility in that if there is no input for about 5 seconds it will close the file automatically. It is also quite user friendly, "clicking" a file icon with an incoming arrow for downloading data and a file icon with an outgoing arrow to upload data.
   Another option is to use the Serial Port Terminal Emulation Software, availiable from the download page of The Creative Communication Consultant

4. Operation

   • Set the communication software on the PC to 8 bit no parity.

   • Set the Baud rate to 9.6kbit/s

   • Set the Baud rate on the Organ serial port to 9.6kbit/s

   • Set the communication software on the PC to spool data directly to an empty file.

   • Set the Organ to send data to the RS232 port, Rhythms, Registrations etc. as required.

   • When data transmisson is complete ensure that the file on the PC is closed, some softwares can do this automatically.

5. Organ Specific

   For way the above procedures are performed will naturally depend both on the type of organ you have and the software and operating system in your PC or MAC. As I have a WERSI Beta myself I cannot describe the procedures for all WERSI models. It will be necessary to consult your organ handbook on this. If anyone wishes to send me any information on their particular model, I will copy them to this page.

   The procedures for the BETA are as follows:-

   • To set the Baud rate to 9.6kbit/s. "Compute","W","Compute".

   • To download file, Rhythms and Instruments, "Interface","W","Compute".

   • To Upload file, "Interface",""W","E","R","S","I","Compute".

   File sizes:-

   • WERSI DX300 = 6,984 bytes

   • WERSI DX350 = 9,404 bytes

   • WERSI DX400/500 = 16,412 bytes

   Note: the file sizes above are a good guide that the procedure has been performed correctly