A-Series System Files (SYSTEM / SYSTEM2)

The A-series SYSTEM and SYSTEM2 files store partition-level sampler configuration separately from Programs and Volumes. A normal Volume save does not contain this environment. These records use the PRF3 type, but the type tag alone does not identify a System File: pathname, exact record size and the inner signature also matter.

Offsets below are hexadecimal. Body offsets start after the 0x30-byte shared SFS record envelope. Add 0x30 for a logical-file offset. The parameter area begins at body 0x20; a parameter-area offset is therefore body offset minus 0x20. These offsets must not be substituted directly for MIDI transfer offsets. Multi-byte numeric fields are big-endian unless stated otherwise.

Framing And Model Differences

Partition-relative path	Model	Logical file size	Body size	Parameter area
\PRF3\SYSTEM	A3000	0x430	0x400	Body 0x020..0x367; 0x98 trailing bytes
\PRF3\SYSTEM2	A4000/A5000	0x1030	0x1000	Body 0x020..0xfff

The shared envelope begins with FSFSDEV3SPLXPRF3. Each body begins with a 0x20-byte header. The following byte values describe the listed software versions; version text is not an independent hardware-model identifier.

Body offset	Size	SYSTEM	SYSTEM2
0x00	4	Signature 21 52 05 31	Signature de ad fa ce
0x04..0x07	4	Unspecified	Unspecified
0x08..0x0c	5	Version text 0200A for V2	0107A for 1.07; 0150A for 1.50
0x0d	1	Unspecified	Unspecified
0x0e	1	Storage revision 0	Storage revision 0 or 1
0x0f..0x1f	17	Unspecified	Unspecified

The version text occupies exactly five bytes; 0x0d is not specified as a required string terminator. A reset does not establish complete initial values for the unspecified header bytes. Preserve them when modifying an existing file.

SYSTEM2 revision does not distinguish A4000 from A5000. Both revisions store 32 Multi assignments; A4000 uses 16 parts and A5000 uses 32. A3000 has neither the saved Program Mode nor the Multi Part table.

System Load does not apply every saved byte. A3000 applies body [0x020,0x368). A4000/A5000 software 1.07 applies [0x020,0x664) and 1.50 applies [0x020,0x67c). The remaining saved bytes are not thereby padding or free space. Preserve them. Software 1.07 accepts revision 0; 1.50 accepts revision 1 and has a revision-0 conversion path. Its complete conversion and hardware-dependent initialization rules are not specified here.

The header is read separately. A3000 then reads body [0x020,0x368); A4000/A5000 reads [0x020,0x1000) before applying its shorter prefix. A short read within a requested range aborts parameter application. This does not establish the missing contents of a truncated saved suffix or permit reconstructing them with zeros.

System Bulk MIDI transfer has different framing from a disk file: payload bytes are sent as high and low nibbles, without the System header. A3000 V2 transmits body [0x020,0x368). A4000/A5000 software 1.07 and 1.50 transmit [0x020,0x1000), including the saved suffix, but receive application covers only the shorter prefix listed above for each version. Inclusion in a transfer does not make unspecified bytes editable settings or establish their defaults.

Region Map

Ranges in this table are half-open; some storage roles overlap.

Region	SYSTEM body	SYSTEM2 body
Global preferences	[0x030,0x05e)	[0x030,0x1f0)
Disk configuration transfer	[0x060,0x074)	[0x1f0,0x200)
Effect favorites	[0x070,0x0f0)	[0x200,0x300)
Panel/command preferences	[0x0f0,0x130)	[0x300,0x340)
Recording effects and configuration	[0x130,0x1ca)	[0x340,0x3f0)
Service startup state	[0x1d0,0x1d8)	[0x3f4,0x3fc)
Auxiliary MIDI setup	[0x1d8,0x1e0)	[0x3fc,0x405)
Registered Sample parameter block	[0x1e8,0x2a4)	[0x40c,0x4ec)
Registered Program region	[0x2a4,0x368)	[0x4ec,0x64c)
Sequence MIDI-port configuration	Not present	[0x64c,0x65c)
Digital-output configuration	Not present	[0x65c,0x664)
mLAN configuration and initialization state, software 1.50	Not present	[0x664,0x674)

Gaps between these regions include disk-selection and auxiliary state, not automatically zero padding. In SYSTEM the disk cache at [0x060,0x074) overlaps the first four favorite bytes. These are not independent storage allocations. Remaining auxiliary MIDI meanings and complete mLAN initialization rules are not fully specified.

In both layouts, body 0x020 and [0x029,0x030) have no specified individual meaning or required initial value. The neighboring disk-state reset changes only 0x021, 0x022, 0x023, 0x024 and 0x025; it does not clear these eight unspecified bytes. Preserve them during unrelated edits. Their inclusion in a complete configuration transfer does not make them editable settings.

Unspecified Intervals

The following intervals have no specified per-byte parameter meaning. Retain them exactly when editing neighboring settings; they are not alignment padding.

Region	SYSTEM body	SYSTEM2 body	Modification constraint
Global/disk gap	[0x05e,0x060)	Not present	Outside both adjacent parameter blocks
Recording configuration tail	[0x1c3,0x1ca)	[0x3ec,0x3f0)	Inside the recording block; reset clears these bytes, but nonzero retained values must not be normalized
Recording/service gap	[0x1ca,0x1d0)	[0x3f0,0x3f4)	Outside recording and service blocks
MIDI/registered-state gap	[0x1e0,0x1e8)	[0x405,0x40c)	Not extra auxiliary MIDI selectors
Registered-state tail	[0x34a,0x368)	[0x642,0x64c)	Included in the shared registered-state load, outside the registered Sample/Program parameter copies
Applied extension remainder, software 1.50	Not present	[0x674,0x67c)	Applied by System Load, but outside the 16-byte mLAN block; meaning and initial values unspecified

SYSTEM's saved-only suffix is [0x368,0x400). SYSTEM2 software 1.07's non-applied suffix begins at 0x664, and 1.50's begins at 0x67c; both end at 0x1000. These suffixes remain part of the saved file even though normal System Load does not apply them. Their internal roles and complete initial values are unspecified. Neither a larger save/transfer size nor a neighboring block's reset values authorize manufacturing or truncating them.

Service Startup State

The first byte at SYSTEM 0x1d0 / SYSTEM2 0x3f4 is a service/test startup request. Zero is inactive; values 1 and 2 request test-entry modes whose exact mode names are unspecified. This is not a normal user preference. Reset clears the complete eight-byte block; System Load clears a nonzero first byte. The other seven bytes have no specified individual meaning. Preserve the block when modifying unrelated settings; do not use it to author service requests or apply load-time normalization to a lossless file rewrite.

Sequence Port And Digital Output

These fields have the same encoding in both SYSTEM2 revisions and are not present in the A3000 SYSTEM layout.

Body offset	Size	Setting	Stored values
0x64c	1	Sequence recording port and playback channel group	0 = B, 1 = A
0x65c	1	Digital coaxial/optical output bit depth	0 = 20 bits, 1 = 24 bits

Port A records MIDI IN-A and plays through channels A01..A16; port B uses MIDI IN-B and B01..B16. A4000 has no second MIDI input or editable port choice and uses the A value on load. Storage revision does not identify that hardware capability. The digital bit-depth choice is 20/24, not 16/24, and does not alter stored Wave Data resolution.

Reset clears the 16-byte sequence block and sets its first byte to 1; it clears the eight-byte digital block to 0. System Load converts a digital selector above 1 to 0 in working memory, without rewriting the saved byte. An unrelated file edit must preserve the original saved values rather than apply these load-time adjustments.

The remaining 15 sequence bytes and 7 digital bytes have no specified individual meaning. Preserve them when editing either scalar. Their block reset values do not establish a complete set of defaults for constructing a new System File.

Disk Preferences

Setting	SYSTEM body	SYSTEM2 body	Encoding
Self ID	0x60	0x1f0	SCSI ID 0..7
Mount selections	0x61, byte	0x1f4, BE32	Set bit selects a mounted device
Top Partition	0x68	0x1fc	Stored zero-based; display adds1

Mount bits 0..7 select SCSI IDs 0..7. SYSTEM2 adds bit 8 for IDE master and bit 9 for IDE slave. Preserve its remaining bits. The sampler cannot mount its own SCSI ID. System Load masks Self ID to three bits and clears the corresponding mount bit. When changing saved ID or mount selections, clear the final own-ID bit and reject an explicit request to mount that ID; retain other selections. An unrelated edit must not normalize these fields. A saved ID change does not assert that the ID is unused on the connected bus or change live hardware.

Top Partition selects the beginning of an eight-partition AKAI import window, not an SFS partition-allocation limit. The starting index is adjusted locally when fewer than eight partitions remain; this does not rewrite the saved selection. The sampler editor permits displayed 1..99 (stored 0..98), but System Load resets stored values above 97 to 0. Consequently displayed 99 is not a load-stable saved selection; use 1..98 for edits intended to survive loading. Retain an existing 99 or other unrequested raw value rather than repairing it as a side effect of an unrelated edit.

Random State

SYSTEM body 0x64..0x67 and SYSTEM2 body 0x1f8..0x1fb contain a big-endian 32-bit pseudorandom seed accumulator. Loading supplies it as a generator seed; disk activity adds generated values to the cached accumulator, which is later included in disk-configuration saves. It is not a checksum or a direct snapshot of the generator's current internal state.

The separate big-endian 16-bit value at body 0x26..0x27 supplies another disk operation seed and is incremented after use. The generator algorithms and whether these seed sources share a generator differ between generations. Neither value is an audio parameter or a stable file identifier. Preserve both during unrelated edits rather than advancing, synchronizing or zeroing them. The accumulator can nevertheless contribute to generated names. Canonical initial seed values remain unspecified.

Disk Conflict State

In A3000 V2 SYSTEM and SYSTEM2 software1.07/1.50, body 0x28 stores the One/All scope of same-name conflict dialogs: zero means One, nonzero means All, and interactive changes store0 or1. Disk-command entry resets it to One. This byte is separate from the selected Rename, Skip, Replace or Abort action and does not establish a persistent Replace All default.

Body 0x23 and 0x24 supply the initial values for load and save conflict-policy caches respectively. Values 0/1/3/4/5 select asking, renaming, skipping, replacing and aborting, subject to the object and conflict type. Value2 has a separate acceptance path whose full meaning is unspecified. Values above5 are read as0 without necessarily rewriting storage. An All decision can update a working cache without changing its saved initial value. Value2 is accepted for a System-file overwrite but does not have an ordinary conflict-dialog action; its intended use remains unspecified.

Preserve these bytes during unrelated preference edits. They are command state, not musical parameters. Body 0x21 has boolean access, 0x25 has byte access, and 0x22 is cleared with the prefix reset, but their operational meanings remain unspecified. They must not be treated as freely disposable padding.

Auxiliary MIDI Setup

SYSTEM stores eight bytes at 0x1d8; SYSTEM2 stores nine at 0x3fc. Native A3000 V2 and SYSTEM2 software1.50 share the receive-filter and timeout roles described below, but differ in how loading applies the saved filters. The five ordinary preferences have the same storage domains in both formats: SYSTEM uses 0x1da..0x1dd for protection and the three receive-disable flags, and 0x1df for device number. Its additional Program Change filter is at 0x1d8, unspecified setting at 0x1d9, and timeout recovery bypass at 0x1de. SYSTEM has no saved receive-port selector.

SYSTEM2 body offset	Meaning	Stored domain
0x3fc	Additional incoming Program Change filter	0 receive, 1 filter
0x3fd	Unspecified setting	0..15; preserve its value
0x3fe	Bulk Protect	0 off, 1 on
0x3ff	Channel Aftertouch reception	0 receive, 1 disable
0x400	Control Change reception	0 receive, 1 disable
0x401	Pitch Bend reception	0 receive, 1 disable
0x402	Internal Active Sensing timeout recovery bypass	Boolean; see below
0x403	MIDI device number	0 off, 1..16 numbered, 17 all
0x404	SysEx receive port	0 A, 1 B; A4000 uses A

The additional Program Change filter is separate from the global Program Change preference. Do not collapse them into one stored field. The internal byte at 0x402 bypasses subsequent timeout recovery when set, but does not disable Active Sensing monitoring or prevent the receive queue from being reset first. Its intended user-facing use remains unspecified; it is not a general "Active Sensing off" switch.

Loading normalizes invalid booleans and the unspecified 0x3fd setting to zero, and invalid device numbers to17. Single-port hardware applies port A regardless of the saved port byte. Those working-state rules do not authorize rewriting unrelated bytes during a lossless copy or a targeted edit. Protection, the three ordinary receive-disable flags, device number and an available SysEx port can be changed independently without altering the other saved bytes. Preserve relative bytes0,1 and6 on these edits. A3000's MIDI settings load step restores and validates these saved values without applying the four live receive filters. Their subsequent activation timing is unspecified; changing a saved value is distinct from applying a live control change. Internal-switch use and complete-file initialization remain separate limitations.

mLAN Extension

Software 1.50 uses body [0x664,0x674) for mLAN configuration and retained interface state. Applicability depends on interface availability; a SYSTEM2 file does not prove that the receiving device has that interface attached. These selections are distinct from Basic Receive Channel and Program routing. Changing either saved input selection does not require changing the other selection or the retained initialization state. Preserve the remaining bytes of this block on such an edit. MIDI source 2 requires dual-port hardware. These routing fields belong to storage revision 1; revision 0 does not apply this extension. An out-of-domain input selection does not establish a default and need not be changed when editing the other input selection.

The mLAN page's Output Level Offset, Word Clock Mode and Nickname are separate interface settings, not fields in this System block. Output Level Offset has five choices, +0, +6, +12, +18 and +24 dB. Word Clock includes live internal/external status, and Nickname is a ten-byte interface name. Do not place these values in the unspecified bytes at 0x666..0x671.

Body offset	Meaning	Stored values or constraint
0x664	MIDI input source	0 MIDI connectors; 1 mLAN A; 2 mLAN B
0x665	Audio input source	0 ADIn; 1 mLAN
0x666..0x671	Unspecified interior state	Preserve on unrelated edits
0x672	Interface initialization-completed marker	Zero requires initialization; successful initialization sets 1
0x673	Retained initialization routing and flags	See below; not an ordinary preference

On single-MIDI-port hardware, MIDI source 1 is displayed as mLAN rather than mLAN A, and a loaded selection 2 is applied as 1. This does not change the meaning of the saved byte or authorize normalizing it during a lossless copy.

When initialization is needed, bit 0 of 0x673 selects routing value 1; otherwise bit 1 selects routing value 2. If neither is set, initialization fails. Bit 0 takes precedence when both are set. Diagnostic preparation stores 0x81 or 0x82 with completion zero after its successful selected-port check. Bit 7 marks that preparation; its wider meaning is unspecified, and it is not an ordinary on/off preference. Bits 2..6 have no defined independent setting. Preserve them rather than treating them as reserved-zero fields.

Interactive initialization retains the interface's cached nickname; pending startup initialization supplies the model name as the initial nickname. Initialization also provisions vendor/model and audio/MIDI endpoint labels in the external interface. These strings are not stored in 0x666..0x671. The completion byte is set only after the external command sequence succeeds; the other retained bytes are not a substitute for the interface's live identity or its command responses.

Reset of this block clears its first 14 bytes but retains 0x672/0x673. The retained marker does not establish initialization on another device. Do not synthesize it as 1 to bypass initialization or assume that an all-zero block is a valid fresh configuration. The interior bytes retain unspecified meanings; portable initialization cannot be derived from this block without the target interface's state and initialization contract.

Global Preferences

This table uses offsets relative to body 0x030. All fields are one byte unless a range is given. Signed fields use two's complement.

Relative offset	Meaning	Stored domain
0x00	Master fine tune	s8, -63..63
0x01, 0x02	Master coarse tune, transpose	s8, -127..127
0x03	Velocity curve selection	0..17
0x04	Basic Receive Channel	SYSTEM 0..15; SYSTEM2 0..31
0x05	Stereo-to-assignable output selection	0..5
0x06	Receive, wave-edit and audition flags	See below
0x07..0x0a	Four knob transmit channels	s8, SYSTEM -1..16; SYSTEM2 -1..32
0x0b..0x0e	Four knob controller devices	0..120
0x0f..0x14	Six function-key transmit channels	SYSTEM 0..16; SYSTEM2 0..32
0x15..0x1a	Six function-key notes	0..127
0x1b..0x20	Six function-key velocities	1..127
0x21	Stereo output-level offset selection	0..4
0x22, 0x23	Total EQ low-boost frequency and gain	Frequency 4..40; gain 52..76
0x24	Remix type / variation	High / low nibble
0x25..0x27	Total EQ low frequency/gain/width	4..40, 52..76, 10..120
0x28..0x2a	Total EQ mid frequency/gain/width	4..58, 52..76, 10..120
0x2b..0x2d	Total EQ high frequency/gain/width	28..58, 52..76, 10..120
0x2e	SYSTEM2 Program Mode	0 Single, 1 Multi
0x2f	SYSTEM2 additional flags	Bit 0 Remix auto audition; bit 1 knob MIDI out; bit 2 function-key MIDI out
0x30..0x4f	SYSTEM2 Multi Part Programs	Each 1..128
0x1b8, 0x1b9	SYSTEM2 Remix zone start/end	0..7, 1..8; start less than end
0x1ba..0x1be	SYSTEM2 five assignable output offsets	Each 0..4
0x1bf	SYSTEM2 working-Program marker	Transient selection state, cleared on load

The saved SYSTEM2 global block ends at relative 0x1c0 (body 0x1f0). Resolved Program references are runtime state, not additional fields following this block. Preserve the subsequent disk-settings region as a separate section; do not append or serialize runtime pointers there.

Basic Receive uses 0..15 for A01..A16 and 16..31 for B01..B16. Transmit selection 16 means Basic Receive; SYSTEM2 transmit selections 17..32 mean B01..B16. Knob transmit selection -1 means audition. The Multi table stores direct Program numbers, not the MIDI transfer representation 0..127. The part matching Basic Receive is the master part. Multi part channels override the Sample/Bank Rch Assign settings inside the selected Programs.

Global flag byte 0x06 assigns bits 0..7 to Omni, Program Change Enable, wave-length lock, auto zero, auto snap, audition with Easy Edit, audition with effects, and Play & Load. Mode selection clears Omni. Length lock, auto zero and auto snap are mutually exclusive edit options. The assignable output duplicating Stereo Out has no independently effective level offset.

Total EQ gain selection 64 is neutral; low boost has no width field. Output offsets and frequency selections are encoded choices, not literal dB or Hz values. The MIDI-out bits in SYSTEM2 byte 0x2f are load-sensitive; their stored presence does not establish a durable enabled setting. Preserve unrelated bits instead of inventing initialization values.

SYSTEM Remix type/variation domains are 0..4 / 0..3; SYSTEM2 domains are 0..9 / 0..7. SYSTEM2 stores five registered recipes as three arrays: duration codes at relative 0x50, captured random choices at 0xc8, and processing flags at 0x140. Each array has five consecutive 24-byte slots. Keep slot order and unused tails. Duration zero terminates a recipe; a zero first duration leaves the source loop unchanged. Nonempty lanes must terminate within their 24 bytes before being used to construct a new recipe.

For a source loop of N frames, let E = floor(N/8). Duration codes 1, 2, 9 and 8 consume E, 2*E, floor(N/16) and floor(N/32) frames, respectively. The full Remix zone covers 8*E frames. Short-slice patterns can produce fewer frames than that zone and leave part of its result dependent on previous working-buffer contents. A nominal total of one loop is therefore not enough to guarantee a fully defined result for every loop length. Patterns made only of 1 and 2 with count(1)+2*count(2)=8 fill that zone for every length. Stereo source coordinates and Gate processing have additional dependencies; this arithmetic alone is not a complete construction rule.

The generated processing bytes have these meanings:

Value (decimal)	Operation
0	Copy the corresponding source segment
1	Copy a captured random source slice
3	Reverse a captured random source slice
5	Copy from the source position 2*E frames after loop start
6	Silence
11	LoFi processing of a captured random source slice
19	Pitch processing of a captured random source slice
35	Gate; depends on working descriptor state not stored in the recipe

For duration 2, the low two random-choice bits select a quarter-sized source slice; otherwise the low three bits select an eighth start. LoFi and Pitch also use random bit 0 for their processing variant. Keep the whole captured byte. Copy, fixed-source and silence steps capture zero rather than a random choice. Processing bytes are complete operations, not freely combinable flags.

A replacement made only from durations 1/2 totaling eight eighths and the non-Gate operations above has no short-slice rounding gap. It has at most eight active steps, followed by zero in all three lanes through the end of that slot. An empty replacement clears the three lanes. Replacing one slot must not alter the other slots or normalize their unused tails. These storage rules do not validate future source capacity. Stereo execution requires matching active loop windows: generation uses the primary window for both lanes, while publication uses each lane's own window.

Stored type selections 5..9 refer to User1..User5, but types 8/9 do not survive loading: the complete selection byte is reset. This affects the saved selection, not the contents of the fourth and fifth recipe slots. Gate and short-slice recipes retain dependencies on working state or source geometry; the file does not carry that missing context.

Recording Settings

Each recording region starts with three 0x28-byte effect blocks. Their layout matches the Program effect blocks: SYSTEM uses type byte 7, SYSTEM2 uses type byte 6, and sixteen u16be words begin at byte 8. There are three recording effects on every model, including A5000. Ordinary effect types are 0..54 on A3000 and 0..96 on A4000/A5000. Output destinations are 0..5 on A3000/A4000 and 0..8 on A5000. Type changes replace the complete generation-specific parameter vector; bypass does not reset it. Unused words are not independent controls.

Configuration begins 0x78 bytes into the recording region: body 0x1a8 for SYSTEM, 0x3b8 for SYSTEM2. Offsets below are configuration-relative.

Offset	Meaning	Encoding/domain
0x00	Record type	0 Replc, 1 New, 2 New+; SYSTEM2 also 3 Save
0x01, 0x02	Mono/stereo, input selection	0..1, 0..4
0x03, 0x04	Frequency, pre-trigger selections	0..6, 0..5
0x05, 0x06	Start/stop trigger selections	Each 0..1
0x07, 0x08	Start/stop edge level	Each 0..63
0x09	Map destination	0..2, dependent on record type
0x0a	Low key	s8 -1..127; -1 is original key
0x0b	High key	u8 0..128; 128 is original key
0x0c, 0x0d	Original key, auto normalize	0..127, 0..1
0x0e	External SCSI ID	s8 -1..7
0x0f, 0x10	External CD track/index	SYSTEM 1..255; SYSTEM2 1..99
0x11, 0x12	Monitor output/level	0..5, 0..127
0x13	Click level	0..127
0x14..0x15	Click tempo	u16be hundredths, 8000..15999
0x16	Click beat	1..15
0x17, 0x18	Monitor enable, map auto	Each 0..1
0x19, 0x1a	Map original key, map all keys	0..127, 0..1
0x1b..0x22	SYSTEM2 destination disk cache	8 bytes
0x23..0x32	SYSTEM2 destination volume cache	16 bytes
0x33	SYSTEM2 A/D input gain selection	0..1

For inputs 0..2, frequency selections display as 44.1k, 22k, 22kLoFi, 11k, 11kLoFi, 5k, 5kLoFi. For digital/optical inputs 3..4, choices 0..3 instead mean ext, ext/2, ext/4, ext/8. Display strings are not exact sample-rate measurements. Selecting digital/optical input forces stereo, caps the frequency choice at 3 and resets monitor output to zero. Monitor level is not an independent setting in those input modes.

New limits map destination to 0..1; New+ allows 0..2. Replc and Save do not offer independent destination-map editing. Effective low key must not exceed effective high key after original-key substitution. CD track/index limits for an actual operation depend on the inserted disc. Destination cache bytes are snapshots, not a reliable identifier of a currently selected recording target.

Effect Favorites

Each effect row occupies two bytes and stores four zero-based parameter selections: high nibble then low nibble of the first byte, followed by high then low nibble of the second. SYSTEM uses raw effect-ID order for 55 ordinary effects; SYSTEM2 uses displayed effect-number order for 97 ordinary effects. The complete areas occupy 128 and 256 bytes respectively, including dormant rows. These ordering schemes must not be interchanged.

A selection identifies a visible effect parameter. Repeated selections are legal. SYSTEM offers at most the number of visible parameters, capped at four positions; SYSTEM2 offers four positions for nonempty effects. Through has no editable favorites. Unavailable selections and dormant nibbles are retained state, not instructions to reset other favorites or effect parameter words.

Panel And Command Preferences

Each panel area is 64 bytes. The table uses decimal byte indices relative to body 0xf0 for SYSTEM and 0x300 for SYSTEM2. Choices are stored indices, not enum values from a software interface.

Index	Meaning	SYSTEM	SYSTEM2
0	Format drive selection	0..7	0..9
1	Effect edit mode	0 Full, 1 Favorite	Same
2..5	Knobs 2..5 control types	0 Off, 1 On, 2..4 Step 1..3	Same
6	Assignable Key	0 Knob Control, 1 Damp, 2 Controller Reset, 3 Function Key Play, 4 Knob & Function Key, 5 MIDI to Sample	Same
7	Audition trigger	0 Normal, 1 Toggle	Same
8	Function selection	0 First, 1 Last, 2 Hold	Same
9	Page selection	0 First, 1 Last	Same
10	Note display	0 Name, 1 Number	Same
11	Format type	0..2 Quick/2HD/2DD	0..5 Logical/Physical/OnePartition/Quick/2HD/2DD
12	Sample name ordering	0 no name sort, 1 forward, 2 backward	Unspecified
13	Program-on placement	0 top, 1 mixed	Unspecified
14	Bank member visibility	0 hide, 1 show	Unspecified
15	End display coordinates	0 Address, 1 Length, 2 Time, 3 Beat, 4 Graph	0..3, no Graph
16	Import view	Unspecified	0 All, 1 Sample Bank, 2 Sample, 3 Sequence
17	Knob 1 type	0 Page, 1 Sample	Same
18	Audition NameView	0 enabled, 1 disabled	Semantics incomplete
19	Layer-selection scope	0 all pages, 1 selection page	0 all pages, 1 Tree page
20	MIDI-to-Sample NameView	0 enabled, 1 disabled	Unspecified
21	Unspecified	Preserve	Preserve
22	Sample sort	Unspecified	0 Off, 1 Name, 2 Rch&Name
23, 24	Tree/Bank sort	Unspecified	0 Off, 1 Name, 2 Status&Name
25	CD-R SCSI ID	Unspecified	0..7
26	CD-R write speed	Unspecified	0..4 mean x1/x2/x4/x6/x8
27	Service state	Unspecified	Test Mode popup type; not an ordinary preference
28..63	Remaining storage	Semantics incomplete	Semantics incomplete

These bytes store selections, not commands: changing a Format choice does not format a disk; changing Import view or CD-R speed does not start either operation. End display coordinates are not a wave boundary or loop mode. SYSTEM NameView booleans have inverted storage polarity. Do not transfer meanings between generations simply because byte indices coincide.

A3000 name sorting compares all 16 unsigned name bytes without trimming or case folding. Bank-before-Sample grouping is independent of sort direction; Program-on top additionally prioritizes assigned objects. Equal-name ordering is not guaranteed stable. InBank hide affects the selection list, not storage.

Registered Sample And Program Templates

The registered Sample contains a 0xbc-byte A3000 or 0xe0-byte A4000/A5000 parameter block, not a complete SBNK object. Both member lanes, bitmaps, flags, EQ coefficients and endpoint caches are stored. A stored second lane does not alone establish active stereo playback or supply a live Wave Data length.

Ordinary Sample allocation applies the registered parameters but clears the new Sample's assignment bitmap at block 0x18..0x27 and flags at 0x28. This does not erase those bytes from the saved template. Preserve them during unrelated template edits; they are not free padding.

Applying a template is not a general recalculation of its EQ coefficients or window caches. Later window repair can be selective, so it must not be relied on to make an inconsistent template valid. Keep dependent values consistent when changing parameters; do not assume a future load will repair them.

The current block uses the SBNK parameter window relative to its 0x0a8 base. A3000 output groups instead occupy block offsets 0xa5/0xa7 with destination domains 0..4/0..5; current groups occupy 0xd6/0xd8 with 0..12. Native bend/coarse-tune domains are 0..13 and -127..127; AEG attack mode is 0..1, versus current 0..2. Do not invent current EQ-type, independent velocity-crossfade widths or portamento rate/time fields in the native block. A3000 EQ uses Peak/Dip behavior, with the same coefficient calculation as current Peak/Dip; it does not supply the current selectable shelf types. EQ gain is stored dB plus 64; displayed LFO speed is stored value plus 1.

In the A3000 block, MAP/OUT byte 0x29 bit0 enables Program-controlled portamento and bit3 enables velocity crossfade. Both are independent switches; changing either preserves all other bits, pitch words and wave/loop coordinates. The native block has no per-Sample portamento rate/time or independent low/high crossfade widths. Conversion to the current layout maps bit0 to portamento type 0 Off or 1 Program and bit3 to both crossfade widths 0 or 5. This conversion rule does not add those extended fields to a native block.

The six A3000 Sample controllers use the prefix at block 0x00..0x17, with device 0..125 and function 0..21. Current controllers use 0xbc..0xd3, with device 0..126 and function 0..36. On a current record change, copy all four bytes to its prefix record and replace a prefix function above21 with zero. Unchanged records can retain unequal copies. Unlike Program A/D routing, current Sample output edits do not project into the legacy output groups. Current portamento type at 0xda also controls MAP/OUT bit0: set it for type1 and clear it for other types.

EQ edits update all five coefficient words from the effective frequency, gain and width, plus the current type where present. Unrelated edits preserve the stored vector. A3000 Peak/Dip calculation does not consume or clear the unassigned current-type bits. Velocity ranges permit equal endpoints. Filter and level scaling breakpoint1 must be strictly below breakpoint2 when editing either point.

Loop mode at block 0x3d is an independent value in 0..5, using the same six modes as a Sample. Changing mode does not move wave or loop coordinates or recalculate their cached endpoints. It does not repair pre-existing invalid windows; those bytes remain separate from the mode setting.

In both generations, root-key, sample-rate and fine-tune edits mirror the selected value to the second stored lane. Pitch-word updates additionally depend on actual Wave Data attachment: only attached lanes have their pitch words recalculated. The calculation uses each lane's stored root, rate and fine tune; attachment is not stored in the registered parameter block. Identical registered parameters can therefore require different pitch-word updates. Neither retained second-lane values nor the topology byte establishes actual bindings. A root/fine change cannot determine all dependent pitch values from the isolated template alone; the intended Wave Data lanes and their later initialization also matter. Special key endpoints are root-relative: when high key is 0x80, an ordinary low key above root must be reduced to root; when low key is 0xff, an ordinary high key below root must be raised to root. Window edits can change both lanes and the cached ends at block 0xb4/0xb8. Length lock determines which endpoint or length is held constant during a start/end edit. These coupled fields must not be treated as independent scalar values in an isolated template.

Wave-window bounds depend on the attached Wave Data capacity. Loop-window bounds instead use the retained primary wave interval: loop start must be at or after wave start and loop end at or before wave end. Zero-length loops at an endpoint are representable. Explicit loop intervals can be changed without attachment information when the retained primary wave start, length and cached end are consistent and do not overflow. This does not establish that the retained wave interval fits an absent or future source.

A complete loop interval consists of start and length. Changing it mirrors start to 0x50/0x54, length to 0x58/0x5c, and writes their sum to the loop-end cache at 0xb8. It does not change the wave interval, pitch or topology. For an explicit interval change, a retained unmodified start or length is a coordinate of that interval; Length Lock governs panel endpoint gestures, not the representation of an explicitly supplied interval.

Expand Detune at block 0x6a and Dephase at 0x6b can alter the expanded-mono state at 0x28 bit2. When no right member is bound and either effective value is nonzero, expansion duplicates the left binding, pitch and wave/loop windows into the right lane. When a right member is bound, bit2 is set and both effective values are zero, collapse clears the right binding and bit2 but retains the right pitch and window values. A true stereo pair without bit2 is not replaced. Enabled Sample Bank overrides determine the effective values independently. Width at 0x6c is separate and does not trigger these transitions.

The registered block contains neither actual member bindings nor the Bank context. Identical stored templates can therefore require different topology updates. Retained right-lane values or bit2 alone cannot determine which update is needed, and applying a template is not an unconditional topology repair. Detune/Dephase changes require a defined member/application context; they are not independent scalar edits of the isolated block.

Registered Program storage is also rearranged, not an ordinary PROG payload:

SYSTEM body	SYSTEM2 body	Contents
0x2a4..0x31b	0x4ec..0x563	Three 40-byte effect blocks
0x31c..0x32b	0x564..0x573	Four legacy controller records
Absent	0x574..0x5eb	Effect blocks 4..6
Absent	0x5ec..0x5fb	Four current controller records
Absent	0x5fc..0x623	Port-B maps, extra effect connection, right/extended A/D, StepWave and retained suffix
0x32c..0x333	0x624..0x62b	Retained common prefix
0x334..0x349	0x62c..0x641	Common effect/A-D/LFO, level, transpose and portamento fields
0x34a..0x367	0x642..0x64b	Suffix with incomplete semantics

Common fields and effects follow their generation's parameter encoding. A3000's four Program controllers occupy 0x31c..0x32b, with four bytes per record: device 0..125, function 0..63, type 0..3, and signed range -63..63. There is no second registered controller copy in SYSTEM. SYSTEM2 has both the legacy and current controller copies shown above.

On a current controller record change, copy its four bytes to the corresponding legacy record and replace a legacy function above 63 with zero. A no-op edit does not require normalizing previously unequal copies. A3000 has no such projection. Its common flag byte 0x334 uses only bit6 for LFO synchronization; preserve bit7. Its LFO waveform domain is 0..5, versus current 0..6.

A3000 has shared A/D routing, not an independent right route. Its common-block offsets 0x07..0x0a store alternating destinations and levels, with destination domains 0..4 and 0..5. SYSTEM2's current left outputs at 0x601..0x604 project into common legacy groups at 0x633..0x636 when those outputs change. Output2 destinations 1..5 map unchanged to legacy group2, and 6..9 map to group1 after subtracting5. Output1 is applied afterward: 1..4 map unchanged to group1, and 5..9 map to group2 after subtracting4. Output1 wins when both outputs map to the same group. Other destinations produce no legacy route. Right outputs have no additional legacy group. Clear unmatched legacy destinations but preserve their levels.

Changing a registered effect type resets all 16 parameter words to that type's generation-specific initial values before applying individual word edits. Bypass and unchanged-type edits preserve the words. A3000 stores the type in effect byte7 and retains byte6. SYSTEM2 uses byte6; changing type in slots1..3 also sets legacy byte7 to the type for 0..54, or zero for 55..96. Slots4..6 have no corresponding legacy-type update. Connections and disabled routes retain their dormant parameters.

SYSTEM2 retains six effects and port-B state regardless of whether the saving device exposes every setting. Hardware model and storage revision are separate: A4000 has no independently editable port-B state or effects4..6. The registered prefixes and suffixes remain separate from editable parameters. Source-dependent update rules are not fully specified for every registered Sample field.

Unspecified State And Modification Limits

Header gaps, auxiliary state, native panel tails, parts of registered templates and the unused-by-load suffixes have incomplete semantics. A stored value outside a listed domain is not a default, and an unnamed byte is not free space. Preserve unrelated bytes and do not use saved runtime pointers as persistent identities. Independently constructing a complete System File requires more initialization rules than this specification currently supplies.

For axklib's supported operations, see Writer And Alteration.