The S950 is always a slave; it will never send unless it is told to. This means all data transfers out of the S950 must use two-way communication. The S950 can however receive with an incoming connection only. Reception of sample dump is speeded up with a two-way connection.
Programs and samples are requested by number. In the case of programs this will correspond to the number on the PLAY menu decreased by one. For samples the number will be the order in which they are in the S950's RAM. The program/name catalog sent by the S950 has a number against each name, starting with 0.
When the S950 receives a sample, the name it shows will be that number. Programs are received with an alphanumeric name.
Sample transfer is according to the standard described in the Prophet 2000 manual. This uses system exclusive common which does not include a manufacturer's prefix code. As it does not include a MIDI channel code, any samples sent, or request for samples would be responded to by all samplers on the same MIDI line. The system exclusive common reception enable and disable messages--which DO include a MIDI channel number--can be used to select one of several S950's on the same line.
A further enhancement of the standard sample dump protocol is that when closed loop transmission is used, gaps between blocks may be as long as 10 seconds rather than the 20 msec specified. This allows the computer to use its disk in the middle of a long file. This variation maintains full compatibility with the standard.
There are several parameters associated with an S950 sample that are not included in the Prophet 2000 sample dump. These may be sent with the Akai exclusive sample parameters messages.
The use of the above enhancements will not prevent the S950 from being completely compatible with the Prophet 2000 sample dump format.
The machine code execution facility allows the operating system within the S950's memory to be altered by MIDI messages.
where d0 is the parameter's least significant bit.
Specification for RS232-C:
|Connector||25 pin "D". S950 is female.|
|Levels||High +3V to +15V, low -3V to -15V.|
|Baud rate||300, 600, 1200, 2400, 4800, 9600, and 19200. Also many non-standard rates up to 100000. The default baud rate is 9600; transmission at higher rates than 19200 should use a short cable.|
|Protocol||Hardware handshake using CTS/RTS. Handshake need not be used on rates below 50000 baud, in which case RTS should be tied high.|
The S950 is configured as DCE and should be connected to most computers with a non-switching cable with the following pin connections:
|2||RXD||TXD||Data in to S950|
|3||TXD||RXD||Data out of S950|
|4||CTS||RTS||Clear to send|
|5||RTS||CTS||Request to send|