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Unwritten bytes on a disk are set to zero. Multi-byte values have the lsb first (little-endian). This document refers to the first byte in a block as 'byte 1', not 'byte 0'. All values are decimal unless otherwise stated.
Akai hard disks and CD-ROMs use the same file format as Akai floppy disks, and virtually the same disk format.
Length Format Description
-----------------------------------------------------------
10 ASCII Filename
6 0
1 ASCII File type: 'S'=sample, 'P'=program, etc.
3 unsigned File length in bytes
2 unsigned Starting block on disk
2 S900 ID = {0,0}Bytes 1536 to 3136 (1536 to
4736 for high density) contain a map of how the blocks on the disk are used, in
the form of 2-byte unsigned integers. For example, if a file starts at block 5,
map entry 5 may contain the value 6, indicating that the next block to read is
block 6. The next block to read is then given by map entry 6. The map entry for
the last block of a file contains the value 32768. Unused blocks have a map
entry of zero. The first 4 blocks are needed for the file entries and map.
Note that the S950 can use high-density disks and can read S1000 disks, but the S900 can only read S900 or S950 low-density disks.
Length Format Description
------------------------------------------------------------
10 ASCII Filename
6 0
4 unsigned Number of sample words
2 unsigned Sample rate (Hz)
2 unsigned Tuning (16ths of a semitone, C3=960)
2 0
1 ASCII Loop mode (O=one-shot, L=loop, A=alt)
1 0
4 unsigned End marker
4 unsigned Start marker
4 unsigned Loop length
20 140,185,0,78,0,0,0,0,0,0,0,0,0,0,224,43,38,0,0,0(I
don't know what is held in the last 20 bytes, but the values shown seem to
work).
You can use lower case letters in filenames (not available from the front panel) but avoid unusual ASCII characters. Do not put two files with the same name on a disk!
The header is followed by the (12-bit signed) sample data, packed in a very strange way: For a sample of N words, the upper 4 bits of the first byte contains the lower 4 bits of the first word. The lower 4 bits of the first byte contain the lower 4 bits of word N/2. The second byte contains the upper 8 bits of the first word. This repeats for the first N bytes, after which there are N/2 bytes containing the upper 8 bits of the last N/2 words.
Character ASCII AKAII
----------------------------------
0 - 9 48 - 57 0 - 9
space 32 10
A - Z 65 - 90 11 - 36
# 35 37
+ 43 38
- 45 39
. 46 40The file entries and map are in the
same position as the S900, but have changed slightly: Length Format Description
----------------------------------------------------------------
12 AKAII Filename
4 32,32,32,32
1 ASCII File type: 's'=sample, 'p'=program, etc.
3 unsigned File length in bytes
2 unsigned Starting block on disk
2 S1000 ID = 0,3Empty entries also have the
S1000 ID byte. Note that file types are lower-case ASCII. The map now uses a
value of 19152 as an end marker, and the first five blocks (file entries and
map) are marked with values of 16384.
There is a volume label at the end of the map (byte 3136 or 4736 depending on density) consisting of a 12 byte AKAII name followed by 0,0,0,ID,0,1,1,0,0,0,50,9,12,255 where ID = 3 for the S1000.
Note that the S01 uses the S1000 format for disks and samples, but with an ID of 1,0 for high density and 0,1 for low-density unused entries. The S1100 probably uses the same format with a different ID.
Length Format Description
--------------------------------------------------------------
1 3
1 Not important: 0 for 22050Hz, 1 for 44100Hz
1 unsigned MIDI root note (C3=60)
12 AKAII Filename
1 128
1 unsigned Number of active loops
2 0,0
1 unsigned Loop mode: 0=in release 1=until release
2=none 3=play to end
1 signed Cents tune -50...+50
1 signed Semi tune -50...+50
4 0,8,2,0
4 unsigned Number of sample words
4 unsigned Start marker
4 unsigned End marker
4 unsigned Loop 1 marker
2 unsigned Loop 1 fine length (65536ths)
4 unsigned Loop 1 coarse length (words)
2 unsigned Loop 1 time (msec. or 9999=infinite)
84 [as above] Loops 2 to 8
4 0,0,255,255
2 unsigned Sampling frequency
10 0,0,0...
The sample data follows the header as signed 16-bit words.
byte description default range/comments
---------------------------------------------------------------------------
1 program ID 1
2-3 first keygroup address 150,0
4-15 program name 10,10,10... AKAII character set
16 MIDI program number 0 0..127
17 MIDI channel 0 0..15, 255=OMNI
18 polyphony 15 1..16
19 priority 1 0=LOW 1=NORM 2=HIGH 3=HOLD
20 low key 24 24..127
21 high key 127 24..127
22 octave shift 0 -2..2
23 aux output select 255 0..7, 255=OFF
24 mix output level 99 0..99
25 mix output pan 0 -50..50
26 volume 80 0..99
27 vel>volume 20 -50..50
28 key>volume 0 -50..50
29 pres>volume 0 -50..50
30 pan lfo rate 50 0..99
31 pan lfo depth 0 0..99
32 pan lfo delay 0 0..99
33 key>pan 0 -50..50
34 lfo rate 50 0..99
35 lfo depth 0 0..99
36 lfo delay 0 0..99
37 mod>lfo depth 30 0..99
38 pres>lfo depth 0 0..99
39 vel>lfo depth 0 0..99
40 bend>pitch 2 0..12 semitones
41 pres>pitch 0 -12..12 semitones
42 keygroup crossfade 0 0=OFF 1=ON
43 number of keygroups 1 1..99
44 (internal use) 0 program number
45-56 key temperament C,C#,D... 0 -25..25 cents
57 fx output 0 0=OFF 1=ON
58 mod>pan 0 -50..50
59 stereo coherence 0 0=OFF 1=ON
60 lfo desync 1 0=OFF 1=ON
61 pitch law 0 0=LINEAR
62 voice re-assign 0 0=OLDEST 1=QUIETEST
63 softped>volume 10 0..99
64 softped>attack 10 0..99
65 softped>filt 10 0..99
66 tune cents 0 -128..127 (-50..50 cents)
67 tune semitones 0 -50..50
68 key>lfo rate 0 -50..50
69 key>lfo depth 0 -50..50
70 key>lfo delay 0 -50..50
71 voice output scale 1 0=-6dB 1=0dB 2=+12dB
72 stereo output scale 0 0=0dB 1=+6dB
73-150 (not used)
byte description default range/comments
---------------------------------------------------------------------------
1 keygroup ID 2
2-3 next keygroup address 44,1 300,450,600,750.. (16-bit)
4 low key 24 24..127
5 high key 127 24..127
6 tune cents 0 -128..127 (-50..50 cents)
7 tune semitones 0 -50..50
8 filter 99 0..99
9 key>filter 12 0..24 semitone/oct
10 vel>filt 0 -50..50
11 pres>filt 0 -50..50
12 env2>filt 0 -50..50
13 env1 attack 0 0..99
14 env1 decay 30 0..99
15 env1 sustain 99 0..99
16 env1 release 45 0..99
17 env1 vel>attack 0 -50..50
18 env1 vel>release 0 -50..50
19 env1 offvel>release 0 -50..50
20 env1 key>dec&rel 0 -50..50
21 env2 attack 0 0..99
22 env2 decay 50 0..99
23 env2 sustain 99 0..99
24 env2 release 45 0..99
25 env2 vel>attack 0 -50..50
26 env2 vel>release 0 -50..50
27 env2 offvel>release 0 -50..50
28 env2 key>dec&rel 0 -50..50
29 vel>env2>filter 0 -50..50
30 env2>pitch 0 -50..50
31 vel zone crossfade 1 0=OFF 1=ON
32 vel zones used 4
33 (internal use) 255
34 (internal use) 255
35-46 sample 1 name 10,10,10... AKAII character set
47 low vel 0 0..127
48 high vel 127 0..127
49 tune cents 0 -128..127 (-50..50 cents)
50 tune semitones 0 -50..50
51 loudness 0 -50..+50
52 filter 0 -50..+50
53 pan 0 -50..+50
54 loop mode 0 0=AS_SAMPLE 1=LOOP_IN_REL
2=LOOP_UNTIL_REL 3=NO_LOOP
4=PLAY_TO_END
55 (internal use) 255
56 (internal use) 255
57-58 (internal use) 44,1
59-82 [repeat 35-58 for sample 2]
83-106 [repeat 35-58 for sample 3]
107-130 [repeat 35-58 for sample 4]
131 beat detune 0 -50..50
132 hold attack until loop 0 0=OFF 1=ON
133-136 sample 1-4 key tracking 0 0=TRACK 1=FIXED
137-140 sample 1-4 aux out offset 0 0..7
141-148 vel>sample start 0 -9999..9999 (16-bit signed)
149 vel>volume offset 0 -50..50
150 (not used)
Length Format Description
--------------------------------------------------------------------
12 AKAII Filename
4 0,0,0,2 (1 for low density?)
1 ASCII + 128 File type: 211=sample, 208=program, etc.
3 unsigned File length in bytes
2 unsigned Starting block on disk
2 S3000 ID = 0,12 or 0,11 for low densityThe
disk label is the same as the S1000 except for the S3000 ID byte. Subtracting
128 from the S3000 file type gives a set of ASCII characters shared with the
earlier samplers: A,O All Settings B SysEx Data C,Y Operating System D Drum Triggers P Program Q Cue List T Take List X Effects Settings
Stereo samples are stored as two separate mono files with the 11th and 12th characters of the filename set to -L or -R. The S01 and S20 use preset filenames of the form AKAI A1#.%1 where # is a hexadecimal character representing the sample number and % is S for mono and left-channel samples or R for right-channel samples.
Length Format Description
----------------------------------------------------------------------
1 3
1 Not important: 0 for 22050Hz, 1 for 44100Hz
1 unsigned char MIDI root note (C3=60)
12 AKAII (see above) Filename
1 128
1 unsigned char Number of active loops
1 unsigned char First active loop (0 for none)
1 0
1 Loop mode: 0=in release 1=until release
2=none 3=play to end
1 signed char Cents tune -50...+50
1 signed char Semi tune -50...+50
4 0,8,2,0
4 unsigned long int Number of sample words
4 unsigned long int Start marker (first word is 0)
4 unsigned long int End marker
4 unsigned long int Loop 1 marker
2 unsigned int Loop 1 fine length (65536ths)
4 unsigned long int Loop 1 coarse length (words)
2 unsigned int Loop 1 time (milliseconds)
84 [as above] Loops 2 to 8
(Loop 5 marker may be 234,255,151,122)
4 0,0,255,255
2 unsigned int Sampling frequency
1 signed char Loop tune offset -50...+50
39 0,0,0...
Sometimes the sampler will insert more blank space at the end of the header! Make sure your samples are at least a few thousand words long or they will not play correctly. The sample data follows the header as signed 16-bit words. For details of the S3000 program format see the SysEx information on Akai's web site.
The MPC2000 and other related models use DOS formatted disks. Samples are saved with a .SND extension and contain 16-bit signed data after a 42 byte header:
Length Format Description
----------------------------------------------------------------------
2 1,4
16 ASCII Filename (without extension, space padded)
1 0
1 unsigned char Level 0...200 (default 100)
1 unsigned char Tune -120...+120
1 unsigned char Channels: 0=Mono 1=Stereo
4 unsigned long Start
4 unsigned long Loop End
4 unsigned long End
4 unsigned long Loop Length
1 unsigned char Loop Mode: 0=Off 1=On
1 unsigned char Beats in loop 1...16 (default 1)
2 unsigned short Sampling frequency (default 44100)
MPC2000 programs have a .PRG extension and are partially described here:
Length Format Description
----------------------------------------------------------------------
2 7,4
2 unsigned short Number of samples 1...64
1 0
Repeat for 64 samples...
16 ASCII Sample Name
1 0
2 30,0
16 ASCII Program Name
15 0,136,120,12,45,0,20,206,50,0,35,64,0,25,0
Repeat for MIDI notes 35...98
1 unsigned char Sample 0...64 (255=none)
24 0,44,0,88,0,0,0,0,0,0,0,0,0,100,0,0,0,0,100,0,0,0,0,0
388 6,0,100,50,100,0,0...(see .PGM file)
Repeat for Pads A01...D12
1 unsigned char Note number 35...98
Akai distribute some of their sound library in the Teledisk .TD0 format. Following a variable length header (including several null-terminated comment lines) data blocks from the floppy disk are stored sequentially. In the uncompressed format each 1024 byte block is preceded by 9 bytes of address information with an additional 4 bytes at each track boundary. Any further information on this mysterious format would be welcomed!
Length Format Description
--------------------------------------------------------------------
4 ASCII Chunk name 'mesa'
4 unsigned long int Chunk length: 141 bytes
141 S3000 sample header (see above)
1 0 Padding to make chunk length evenMESA
II for PC does not use a <mesa> chunk, but uses the standard <smpl>
chunk for tuning and looping information with sample start and end points stored
in a <cue > chunk.
For more information on the WAV file format see http://www.wotsit.org/
RIFF 'WAVE'
<fmt > - Describes mono or stereo 16-bit PCM (plus 2 unused bytes at end)
<fact> - Describes number of sample words (not actually required for PCM)
<smpl> - Tuning and loop information plus 18 bytes of manufacturer specific data
<data> - Waveform data (16-bit signed, interleaved if stereo)
A single loop is supported, with the loop mode held in the manufacturer specific data. The <smpl> chunk is written before the <data> chunk and any other chunks are stripped off by the sampler. To ensure smooth operation filenames should be less than 20 characters with the WAV extension capitalised. The manufacturer specific data (manufacturer 71, product 94) contains the following parameters but can be omitted if not needed:
Length Description Default
----------------------------------------------------------------------
2 1,0
1 Original root note 60
1 Semitone tune +/-36 0
1 Fine tune +/-50 0
1 0
1 Play mode 0=NO LOOPING 1=ONE SHOT 2=LOOP IN REL 3=LOOP TIL REL
3 0,0,0
4 Start point 0
4 End point (number of sample words)
A loop tuning parameter is also stored in the above structure but is not yet implemented in the sampler operating systems.
Program files have an .AKP extension and are described here.
Multi files
(multitimbral setups of programs) have an .AKM extension.
Both formats are
loosely based on the RIFF file format.
Code for the adisk4 program is provided here showing how to re-program the floppy drive for Akai disk access and includes read, write and format functions. Note that the code is primitive both in style and content! The software will work under DOS and Windows 3.x/95/98, but not NT which blocks direct disk access.
Not all PCs can read all Akai disks. Some modern PCs are obviously not as "IBM Compatible" as they should be, but problems can also be caused by the long hard life many Akai floppy drives have had. Some problems can be solved by using a disk formatted in Akai format by the PC rather than the sampler.
This document Copyright ©1995-2000 Paul Kellett (paul.kellett@maxim.abel.co.uk). You may copy and distribute it. If you develop any software based on this information please give me a credit in it (or its documentation) and send me a copy! The information in this document is believed to be correct, though is known to be incomplete and must be used entirely at your own risk.