Rotary Speaker — HLE + bytecode
Rotary Speaker — HLE reconstruction and DSP bytecode
DSPHLE selector 0x19 · program image prog15_rock_rotary · Preview (topology decoded and reconstructed; most panel→cell role mappings are position-decoded).
Leslie: crossover + two Doppler-swept (measured 7.26/3.63 ms) + AM rotors. Rotation rate not in program (canonical speeds).
This page pairs the bytecode the effect runs on the NEC µPD6383GF with the high-level reconstruction that makes it audible in MAME. The reconstruction is not the chip’s microcode — it is a textbook DSP block built from the decoded meaning of that microcode, and reading the two together is how the bytecode is understood (and, in time, driven toward a faithful low-level emulation). See also the signal-flow flowchart.
The bytecode below is the source of truth; the HLE reconstruction is not. The HLE is our best current interpretation and may contain mistakes — where the two disagree, the bytecode wins, and a better HLE should be updated here. This page is the permanent archive of the reference HLE: it is kept here even after the code is eventually removed from the MAME sources.
DSP bytecode (reverse-engineered microprogram)
The disassembled image the chip executes for this effect. Source (regenerable):
dsp/disasm/prog15_rock_rotary.dsm.
; Reverse-engineered disassembly of the KN5000 effects-DSP microcode
; (NEC uPD6383GF), recovered from the original firmware. The microcode is the
; work of its original authors; this is a disassembly for preservation and
; interoperability, and no claim of copyright is made over the disassembled program.
; KN5000 effects-DSP program -- ROCK ROTARY
; image rep algo 15 | slots 15,53 | unit 0 (I-RAM load 84)
; family rotary | confidence high | 86 words, 33 class-A multiplies (6 named)
; role: rock rotary / rotary speaker (shared with algo 53)
; coefficient cursor base 0x00
;
; GENERATED by dsp/tools/gen_dsp_disasm.py -- DO NOT EDIT.
; Put labels/comments in the matching dsp/sym/*.sym; analysis in dsp/algorithms/.
w0 08801308BC ?word 0x08801308BC ; 880.1.30.8BC hi12{ESC ?7 res=080} [external delay-DRAM READ (FORCED, adjudication-round5 sect. 3 -- addr8 bit 6 is the direction field and 0x60 is the WRITE; this REVERSES R1 F1, which bounded the read latency to one repetition when the descriptors need twenty words); this end moves with the user's DELAY (ms) knob, and the delay is READ_CELL - WRITE_CELL; addr8 0x30 also marks the FIRST DRAM access of a body, 37 of 38 distinct images (R3 sect. 6.2). external delay-DRAM access; address = DESCRIPTOR_CELL[k] + G, from the host bank behind pointer ...825 / tag 0x4C (R3, PROVEN BY CONSTRUCTION) -- the k-th class-1 escape word of a body takes the k-th cell of that body's own descriptor block (the IDENTITY map, FORCED in adjudication-round5 sect. 1), so the address is NOT in this word]
w1 0000A0A415 ld acc,c+,(p)+10
; C-RAM[0x00] (coeff, base 0x00 MEASURED)
; coeff C-RAM[0x00] = op0x61[0] (role coeff, INFERRED)
w2 0212AF61D5 mac (p),c+,(p)-10 ; mem[p]<-acc, acc=0
; C-RAM[0x01] (coeff, base 0x00 MEASURED)
; coeff C-RAM[0x01] = op0x61[1] (role coeff, INFERRED)
w3 0202A00216 ?word 0x0202A00216 ; 202.A.00.216 hi12{f98=2 f31=1} cur+ [SPECULATIVE (prospective, not measured): SRC 0x08 = C-RAM[cursor] (the COEFFICIENT), MEASURED: the chorus LFO at iw89 reads L = 114 and acc = 114<<16 exactly, and 114 = C-RAM[0x00] = floor(0.5993*2^23/44100), the ROM's own ramp constant; the rival "sample source" is REFUTED from disk (SQUARING-MULTIPLY item B)]
; C-RAM[0x02] (coeff, base 0x00 MEASURED)
w4 0020200000 ld.b (p)0,(p)+0
w5 002E20000B ?word 0x002E20000B ; 02E.2.00.00B hi12{f31=7 ?5 res=020} [SPECULATIVE (prospective, not measured): SRC 0x00 = mem[ptr]/delay-RAM read; ACT 0x0B = delay-line access (READ/WRITE class-borne)]
w6 009220A700 ?word 0x009220A700 ; 092.2.0A.700 hi12{ST f31=1 ?7 res=080} [SPECULATIVE (prospective, not measured): SRC 0x1C = control/mod source into MAC (100% MAC-consumed; LFO in mod fx, envelope/AGC in dynamics) -- NOT LFO-only: present in 19 non-LFO programs (dsp_datapath_fingerprint)]
w7 0000A00415 ld acc,c+,(p)+0
; C-RAM[0x03] (coeff, base 0x00 MEASURED)
w8 01822F6000 mac.b (p)0,(p)-10
w9 0040000C63 ?word 0x0040000C63 ; 040.0.00.C63 hi12{?6 res=040} [SPECULATIVE (prospective, not measured): SRC 0x11 = ACCB (2nd accumulator)]
w10 00006284CD ?word 0x00006284CD ; 000.6.28.4CD hi12{-} [table-lookup idiom, class-6 addr8 = table selector (INFERRED)]
w11 00124011CE ?word 0x00124011CE ; 012.4.01.1CE hi12{ST f31=1} [table-lookup idiom, third word (INFERRED)]
w12 01042001CE post (p),(p)+0
w13 010220B1CD mac (p),(p)+11
w14 00002FF40E ld acc,(p)-1
w15 0212201000 mac.b (p)0,(p)+1 ; mem[p]<-acc, acc=0
w16 0000A40415 ld acc,c+,(p)+64
; C-RAM[0x04] (coeff, base 0x00 MEASURED)
; coeff C-RAM[0x04] = op0x62[0] (role output-level, INFERRED)
w17 0292A001D3 mac.ta (p),c+,(p)+0 ; store SUPPRESSED (bit7)
; C-RAM[0x05] (coeff, base 0x00 MEASURED)
w18 0212A01452 ?word 0x0212A01452 ; 212.A.01.452 hi12{ST f98=2 f31=1} cur+ [writes mem[ptr] (bit 4); mode 2, so the target IS the pointer]
; C-RAM[0x06] (coeff, base 0x00 MEASURED)
w19 0202A011D5 mac (p),c+,(p)+1
; C-RAM[0x07] (coeff, base 0x00 MEASURED)
w20 0202A011D4 mac.tb (p),c+,(p)+1
; C-RAM[0x08] (coeff, base 0x00 MEASURED)
w21 0202A001D5 mac (p),c+,(p)+0
; C-RAM[0x09] (coeff, base 0x00 MEASURED)
w22 01022FF687 mac.st tb,(p)-1
w23 0804816415 post acc,c
w24 0212AFF407 mac.st acc,c+,(p)-1 ; mem[p]<-acc, acc=0
; C-RAM[0x0A] (coeff, base 0x00 MEASURED)
w25 00002BB647 ld.st ta,(p)-69
w26 0000204407 ld.st acc,(p)+4
w27 0000204447 ?word 0x0000204447 ; 000.2.04.447 hi12{-} [SPECULATIVE (prospective, not measured): SRC 0x11 = ACCB (2nd accumulator)]
w28 09001601D5 dly.w dsc[k],p+96
w29 0192A40000 mac.b (p)0,c+,(p)+64 ; store SUPPRESSED (bit7)
; C-RAM[0x0B] (coeff, base 0x00 MEASURED)
w30 00822001C0 mac.b (p),(p)+0
w31 0C4032044C ldreg r4C,#25 ; immediate -> the register lo12 selects
w32 0A00000041 ?word 0x0A00000041 ; A00.0.00.041 hi12{ESC f98=2} [head of a fixed 3-word template (S-5); operands SRC 0x01/ACT 0x01 dark]
w33 08801202C7 dly.r dsc[k],p+32
w34 0102ABE4C8 ?word 0x0102ABE4C8 ; 102.A.BE.4C8 hi12{f98=1 f31=1} cur+ [gain multiply (same op in phaser all-pass and reverb diffuser)]
; C-RAM[0x0C] (coeff, base 0x00 MEASURED)
w35 0000243407 ld.st acc,(p)+67
w36 0C400001DA ldreg rDA,#0 ; immediate -> the register lo12 selects
w37 00122FC1D5 mac (p),(p)-4 ; mem[p]<-acc, acc=0
w38 01042C01D5 post (p),(p)-64
w39 0102A401D5 mac (p),c+,(p)+64
; C-RAM[0x0D] (coeff, base 0x00 MEASURED)
w40 0000200000 nop
w41 0302A00655 mac ta,c+,(p)+0
; C-RAM[0x0E] (coeff, base 0x00 MEASURED)
w42 02122BE41D ?word 0x02122BE41D ; 212.2.BE.41D hi12{ST f98=2 f31=1} [writes mem[ptr] (bit 4); mode 2, so the target IS the pointer]
w43 0000247407 ld.st acc,(p)+71
w44 0C400001DA ldreg rDA,#0 ; immediate -> the register lo12 selects
w45 00122FC1D5 mac (p),(p)-4 ; mem[p]<-acc, acc=0
w46 01042C01D5 post (p),(p)-64
w47 0102A401D5 mac (p),c+,(p)+64
; C-RAM[0x0F] (coeff, base 0x00 MEASURED)
w48 0000200000 nop
w49 0302A00655 mac ta,c+,(p)+0
; C-RAM[0x10] (coeff, base 0x00 MEASURED)
; coeff C-RAM[0x10] = op0x66[0] (role mix/tap, INFERRED)
w50 02122AC41D ?word 0x02122AC41D ; 212.2.AC.41D hi12{ST f98=2 f31=1} [writes mem[ptr] (bit 4); mode 2, so the target IS the pointer]
w51 0000209407 ld.st acc,(p)+9
w52 0000A501D5 ld (p),c+,(p)+80
; C-RAM[0x11] (coeff, base 0x00 MEASURED)
w53 0292A011D5 mac (p),c+,(p)+1 ; store SUPPRESSED (bit7)
; C-RAM[0x12] (coeff, base 0x00 MEASURED)
w54 0182AFF1D4 mac.tb (p),c+,(p)-1
; C-RAM[0x13] (coeff, base 0x00 MEASURED)
w55 0282A01692 mac tb,c+,(p)+1
; C-RAM[0x14] (coeff, base 0x00 MEASURED)
; coeff C-RAM[0x14] = op0x66[1] (role mix/tap, INFERRED)
w56 080A816000 ?word 0x080A816000 ; 80A.8.16.000 hi12{ESC f31=5} cur [class 8: post-sum step (rescale/round/saturate?), OPERATION UNKNOWN]
w57 02122B0447 ?word 0x02122B0447 ; 212.2.B0.447 hi12{ST f98=2 f31=1} [writes mem[ptr] (bit 4); mode 2, so the target IS the pointer]
w58 00002F6407 ld.st acc,(p)-10
w59 09001601D5 dly.w dsc[k],p+96
w60 0192A5B000 mac.b (p)0,c+,(p)+91 ; store SUPPRESSED (bit7)
; C-RAM[0x15] (coeff, base 0x00 MEASURED)
w61 00822001C0 mac.b (p),(p)+0
w62 0C4032044C ldreg r4C,#25 ; immediate -> the register lo12 selects
w63 0A00000041 ?word 0x0A00000041 ; A00.0.00.041 hi12{ESC f98=2} [head of a fixed 3-word template (S-5); operands SRC 0x01/ACT 0x01 dark]
w64 08801202C7 dly.r dsc[k],p+32
w65 0102AA64C8 ?word 0x0102AA64C8 ; 102.A.A6.4C8 hi12{f98=1 f31=1} cur+ [gain multiply (same op in phaser all-pass and reverb diffuser)]
; C-RAM[0x16] (coeff, base 0x00 MEASURED)
w66 0000A0A412 ld acc,c+,(p)+10
; C-RAM[0x17] (coeff, base 0x00 MEASURED)
w67 0212AF91D5 mac (p),c+,(p)-7 ; mem[p]<-acc, acc=0
; C-RAM[0x18] (coeff, base 0x00 MEASURED)
w68 0202A051D5 mac (p),c+,(p)+5
; C-RAM[0x19] (coeff, base 0x00 MEASURED)
w69 0202AFD1D5 mac (p),c+,(p)-3
; C-RAM[0x1A] (coeff, base 0x00 MEASURED)
w70 0202200000 mac.b (p)0,(p)+0
w71 00002FE407 ld.st acc,(p)-2
w72 00122081C0 mac.b (p),(p)+8 ; mem[p]<-acc, acc=0
w73 09001601D5 dly.w dsc[k],p+96
w74 0192A50000 mac.b (p)0,c+,(p)+80 ; store SUPPRESSED (bit7)
; C-RAM[0x1B] (coeff, base 0x00 MEASURED)
w75 00822001C0 mac.b (p),(p)+0
w76 0C4032044C ldreg r4C,#25 ; immediate -> the register lo12 selects
w77 0A00000041 ?word 0x0A00000041 ; A00.0.00.041 hi12{ESC f98=2} [head of a fixed 3-word template (S-5); operands SRC 0x01/ACT 0x01 dark]
w78 08801202C7 dly.r dsc[k],p+32
w79 0102AA74C8 ?word 0x0102AA74C8 ; 102.A.A7.4C8 hi12{f98=1 f31=1} cur+ [gain multiply (same op in phaser all-pass and reverb diffuser)]
; C-RAM[0x1C] (coeff, base 0x00 MEASURED)
w80 0000A00415 ld acc,c+,(p)+0
; C-RAM[0x1D] (coeff, base 0x00 MEASURED)
; coeff C-RAM[0x1D] = op0x74[0] (role input/tone, INFERRED)
w81 0212A051D5 mac (p),c+,(p)+5 ; mem[p]<-acc, acc=0
; C-RAM[0x1E] (coeff, base 0x00 MEASURED)
w82 0202AF81D5 mac (p),c+,(p)-8
; C-RAM[0x1F] (coeff, base 0x00 MEASURED)
w83 0202AF71D5 mac (p),c+,(p)-9
; C-RAM[0x20] (coeff, base 0x00 MEASURED)
w84 0880160000 dly.w dsc[k],p+96
w85 060210E000 endblk #0E ; END OF BLOCK -- the last word of a block
HLE reconstruction (MAME, kn5000_tonegen.cpp)
The decode of the bytecode above, rebuilt as audible DSP. Two parts: the parameter refresh
(reads the decoded C-RAM coefficient cells once per update) and the per-sample insert (the
signal processing). Default OFF, behind the DSPHLE research port. Source:
src/mame/matsushita/kn5000_tonegen.cpp.
Parameter refresh (decode the C-RAM coefficients):
const bool rot_hle = (dsphle == 0x19);
double rot_tinc = 0.0, rot_binc = 0.0, rot_tdep = 0.0, rot_bdep = 0.0; int rot_tbase = 0, rot_bbase = 0;
if (rot_hle)
{
rot_tinc = 6.8 / double(STREAM_RATE); // treble horn ~6.8 Hz (fast), canonical
rot_binc = 5.7 / double(STREAM_RATE); // bass drum ~5.7 Hz (fast), canonical
rot_tbase = int(320.0 * sr48 + 0.5); // measured Doppler line (7.26 ms)
rot_bbase = int(320.0 * sr48 + 0.5);
rot_tdep = 40.0 * sr48; // Doppler depth (vibrato)
rot_bdep = 24.0 * sr48;
m_rot_lp_l.set_damping(0.88); m_rot_lp_r.set_damping(0.88); // ~800 Hz crossover
}
Per-sample insert (the reconstructed signal path):
if (rot_hle) // ROTARY SPEAKER: crossover + two Doppler-swept, amplitude-modulated rotors
{
const double x = 0.5 * (double(mix_l) + double(mix_r)) / 32768.0;
const double low = m_rot_lp_l.process_one(x), high = x - low;
const double ts = std::sin(TWO_PI * m_rot_tph), bs = std::sin(TWO_PI * m_rot_bph);
m_rot_tph += rot_tinc; if (m_rot_tph >= 1.0) m_rot_tph -= 1.0;
m_rot_bph += rot_binc; if (m_rot_bph >= 1.0) m_rot_bph -= 1.0;
const double ttap = rot_tbase + rot_tdep * 0.5 * (1.0 + ts), btap = rot_bbase + rot_bdep * 0.5 * (1.0 + bs);
m_rot_t_l.write(high); m_rot_t_r.write(high); m_rot_b_l.write(low); m_rot_b_r.write(low);
const double thl = m_rot_t_l.read(ttap), thr = m_rot_t_r.read(ttap + 18.0);
const double bl = m_rot_b_l.read(btap), br = m_rot_b_r.read(btap + 10.0);
const double yl = thl * (0.6 + 0.4 * ts) + bl * (0.7 + 0.3 * bs);
const double yr = thr * (0.6 - 0.4 * ts) + br * (0.7 - 0.3 * bs);
mix_l = int32_t(std::clamp(yl, -1.0, 1.0) * 32767.0);
mix_r = int32_t(std::clamp(yr, -1.0, 1.0) * 32767.0);
}