When the response is an ACK. she S-770 starts data packet transmission. When the response is a Wail, the S-770 pauses data transfer until the next message is received. Each parameter is to be sent Ii>D first. FO 7E cc 0! ss ss 10 ff if fi № gg hh hh hh it Channel number Sample number {0 - 1023) Sample formal (I Gbit) Sample period (1/'sample rate, nanoseconds) Data (word) length Sample loop start point (Wrod number) Sustain loop end |x>im (Word number) Loop time (****) 00 = Towards Only (unidirectional) 01 - Backwards/Forwards (bi - directional) 7F = Off EOX O Data packet The Data packet consists of a Header, Packet number. 120- byie data, Checksum and the End of exclusive (EOX). The packet starts with number 00 up to 7FH and then returns back to 00. The receiving device can judge whether the incoming packet is a new one or retransmitted one by checking the number. Each data is formatted in 3 bytes (7 bits each) /'word, left justfied, upix.t byte first. 40 words comprise a packet with each word containing "0” at lower 5 bits place in the 3rd byte. Checksum is done by an exclusive-OR operation of 7E 02 (packet number> < 120 bytes>. Once the S-770 sends a packet, it monitor the MIDI IN port, and will send out the next packet upon finding an ACK. If NAK instead of ACK, the S-770 retransmits the packet slated in the NAK message. When the S-770 receives a Wait, it waits for a message: maybe ACK, NAK or Cancel. The above prodecures will be repealed until the bytes to be sent arc less than 121. The final packet, therefore, must fill the bianks with "0‘s” lo have 120 daia bytes. The receiving device must send a handshaking flag (ACK) at the end of data receiving. Format ■ Universal System Exclusive Message • Sample dump standard The sample dump standard specifies the following messages to be used for a kind of data transfer. FO 7E 02 kk Channel number Packet number 1 } ) 120 - byte data О Dump request This is a dump request command specifying the sample numtx’r lo be sent from a device at ihe other end of the interface. When the S-770 receives this command, it checks the sample number if it is in the specified range. When in the range, the S 770 will send the correct sample lo the other рапу for dumping. The ,4-770 will not send this message. FO 7E 03 ss ss Channel number Request sample (LSD first} EOX Checksum EOX O ACK A handshake flag meaning ''Received the last data of the packet, send the next data”. The packet number indicates the packet recognized. Format_ FO 7E cc 7F pp F7 Channel number Packet number EOX O NAK A handshake flag warning ’’Received (he last data of Ihe packet incorrectly. Send it again". The packet number indicates that data lo be retransmitted. Format FO 7E cc 7E PP F7 Channel number Packet number EOX 234 O Cancel handshake flag informing “Slop dumping". 'The packet number indicates (he packet to bo rejecled. This message will Ix.* sent when the memory in the receving unit has no room to accommodate another data. rormat__ FO 7F. cc Channel number 7D PP Packet number i:7 i-:ox O Wait A handshake flag requiring "No more packet until signal”. The packet number indicates the packet lo Iw rejected. This message wilt be sent when the receving unit needs lime for being ready fur receiving the next data. After that, ihe receiving unit will send either: 1) an ACK to require the next data transmission or 2) a Cancel, if not want. Formal_ FO IV. cc Channel number 70 pp Packet number FT EOX DIGITAL SAMPLER Date : Jan, 19. 1990 Mode! s-770 MIDI Implementation Chart Version : 1.00 Function ••• Transmitted Recognized Remarks Basic Default X 1 - 16,OFF * 4 * 2 Channel Changed X 1 - 16,OFF * 4 Default X 3 Mode Messages X X Alterd ********* X Note X 21 - 108 Number True Voice ********* 21-108 Velocity Note ON Note OFF X X * 1 X V = 1 - 127 After Key's X * 1 Touch Ch's X * 1 Pitch Bender X * 1 1 X * 1 Modulation 2 X * 1 Breath 7 X * 1 Volume 64 X * 1 Hold 1 0-31 X * 1 * 5 100,101 X * 1 RPC LSB.MSB Control Change 6,38 X * 1 Data Entry LSB.MSB NumberO:P i tch Bend Sens it i v i t y Numberl:Master Tune Prog * 1 0-127 0 - 127 * 1 * 3 Change True # ********* 0-127 System Exclusive * 1 * 1 System Common Song Pos Song Sel Tune X X X X X X System Real Time Clock Commands X X X X Local ON/OFF X X Aux All Notes OFF X 0 (123 - 127) Messages Active Sense Reset X X О X Notes * 1 Can be set to С or X manually and memorized by disk. * 2 Memorized by S- 770, *3 Patch numbers for each program change number can be set in any order. * 4 MIDI channel of each voice group can be set. * 5 Can be set to any Control Number and memorized by disk. Mode I : OMNI ON, POLY Mode 2 : OMNI ON, MONO Mode 3 : OMNI OFF, POLY Mode 4 : OMNI OFF, MONO О : Yes X : No ■ How to read a MIDI Implementa...
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