renamed the digital part
This commit is contained in:
Gordon JC Pearce
parent
5db88ca4ea
commit
ca65162e3f
@ -11,7 +11,7 @@ NAME = chassis
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FILES_DSP = \
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parameters.cpp \
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digital.cpp \
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voicecpu.cpp \
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chassis.cpp \
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voice.cpp
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@ -18,7 +18,12 @@
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// contains the emulation of the digital bits
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#include "digital.hpp"
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// what's with the crazy private variables and all the gotos with crazy labels?
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// this code emulates the uPD7811 code directly (probably inefficiently)
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// to allow for documenting what the variables actually do
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// they're really bitfields holding a bit for each voice
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#include "voicecpu.hpp"
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#include <cmath>
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#include <cstdio>
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@ -31,6 +36,136 @@ bool Voice::isFree() {
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return ff10 == false;
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}
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void Synth::lfoDelay() {
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// compute LFO delay
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uint16_t a, bc, d, ea, tos;
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// 030d: 45 11 3f ONIW $0011,$3F ; are any notes enabled
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// 0310: 4e 59 JRE $036B ; no, just run LFO
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if (!keyon /* ff11 */) goto h036b; // skip ahead if no notes are pressed
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// 0312
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if (!(ff1e & 0x08)) goto h0323; // a note is running, don't reset
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// 0315 no note is running, reset it all
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bc = 0;
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ff56 = 0; // delay envelope
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ff5a = 0; // holdoff timer
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ff1e &= 0xf1; // mask bits in flag byte
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h0323:
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if (!(ff1e & 0x02)) goto h0370; // compute delay envelope
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if (!(ff1e & 0x04)) goto h0388; // compute holdoff timer
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// 032b
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bc |= 0xff00; // initial scaling value?
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h032d:
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tos = bc; // push bc
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// 032e
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a = lfoDepthTable[patchRam.vcoLfo];
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// MUL B; MOV A, EAH
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a = (a * (bc >> 8)) >> 8;
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// 0333 ADDNCW $0064; MVI A, $FF
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a += ff64;
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if (a > 0xff) a = 0xff;
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// 0338 sets up HL to store computed pitch LFO output
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// 33b
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bc = ff4d; // current LFO output
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// 033f
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ea = (bc & 0xff) * a; // MUL C
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d = a; // MOV D,A
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a = (ea >> 8); // MOV A,EAH
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bc &= 0xff00;
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bc |= a; // MOV C,A
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a = d; // MOV A,D
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// 0345
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ea = (bc >> 8) * a; // MUL B
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ea += (bc & 0xff); // EADD EA, C
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// 0349
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ea >>= 3; // divide by eight
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// 034f
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ff51 = ea; // save scaled pitch LFO
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bc = tos; // pop BC, contains scaling amount
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a = patchRam.vcfLfo << 1; // amount is doubled and stored at ff48
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// 0354
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ea = (bc >> 8) * a; // MUL B
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a = ea >> 8; // MOV A, EAH
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bc = ff4d; // current LFO output
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// 035b
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ea = (bc & 0xff) * a; // MUL C
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d = a; // MOV D,A
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a = ea >> 8; // MOV A, EAH
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bc &= 0xff00;
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bc |= a; // MOV C,A
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a = d; // MOV A,D
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ea = (bc >> 8) * a; // MUL B
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ea += (bc & 0xff); // EADD EA,C
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ea >>= 1; // DSLR A
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ff53 = ea; // save scaled VCF LFO
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goto h03a1;
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h036b:
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ff1e |= 0x08; // set LFO flag
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goto h0323;
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h0370: // calculate holdoff time
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// printf("0370 ");
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ea = ff56; // holdoff time
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bc = attackTable[patchRam.lfoDelay]; // stored at ff58
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// 0379
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ea += bc; // DADD EA,BC
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ff56 = ea; // STEAX (DE) which still holds ff56 from 0x370
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a = ea >> 8; // MOV A, EAH
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if (a & 0xc0) goto h0385; // OFFI A, $C0
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bc &= 0xff; // MOV B, 0
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goto h032d;
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h0385:
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ff1e |= 0x02; // stop predelay flag
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h0388:
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// printf("0388 ");
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ea = ff5a; // envelope speed
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// 038d
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bc = lfoDelayTable[patchRam.lfoDelay >> 4]; // delay setting divided by 8 and saved at ff6c
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// printf("---------------------------------------- %04x %04x\n", ea, bc);
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// 0391 DADDNC EA, BC
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if ((ea + bc) > 0xffff) goto h039a;
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ea += bc;
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// 394
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ff5a = ea; // STEAX (HL) hl still contains ff5a
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bc |= (ea & 0xff00); // MOV A, EAH; MOV B, A
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goto h032d;
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h039a:
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ff1e |= 0x04;
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bc |= 0xff; // MVI B, $ff
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goto h032d;
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h03a1:
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// printf("LFO=%04x VCF=%04x flags=%02x holdoff=%04x envelope=%04x\n", ff51, ff53, ff1e, ff56, ff5a);
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return;
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}
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void Voice::calcPitch(Synth &s) {
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uint32_t bc, ea, a;
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@ -145,11 +280,6 @@ h04d5:
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}
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void Voice::on(uint32_t key, bool reset = 0) {
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// what's with the crazy private variables and all the gotos with crazy labels?
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// this code emulates the 78C11 code directly (probably inefficiently)
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// to allow for documenting what the variables actually do
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// they're really bitfields holding a bit for each voice
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// this current implementation doesn't reset the voice
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(void)reset;
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@ -248,139 +378,6 @@ h0590:
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// printf("%04x %d %d %d %d %d \n", ea, ff07, ff08, ff10, ff11, ff33);
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}
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void Synth::lfoDelay() {
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// compute LFO delay
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uint16_t a, bc, d, ea, tos;
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// 030d
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if (!keyon /* ff11 */) goto h036b; // skip ahead if no notes are pressed
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// 0312
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if (!(ff1e & 0x08)) goto h0323; // a note is running, don't reset
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// 0315 no note is running, reset it all
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bc = 0;
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ff56 = 0; // delay envelope
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ff5a = 0; // holdoff timer
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ff1e &= 0xf1; // mask bits in flag byte
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h0323:
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if (!(ff1e & 0x02)) goto h0370; // compute delay envelope
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if (!(ff1e & 0x04)) goto h0388; // compute holdoff timer
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// 032b
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bc |= 0xff00; // initial scaling value?
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// printf("0323 ");
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h032d:
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tos = bc; // push bc
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// 032e
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a = lfoDepthTable[patchRam.vcoLfo];
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// MUL B; MOV A, EAH
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a = (a * (bc >> 8)) >> 8;
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// 0333 ADDNCW $0064; MVI A, $FF
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a += ff64;
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if (a > 0xff) a = 0xff;
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// 0338 sets up HL to store computed pitch LFO output
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// 33b
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bc = ff4d; // current LFO output
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// printf("-----------------------%02x %04x\n", a, bc);
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// 033f
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ea = (bc & 0xff) * a; // MUL C
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d = a; // MOV D,A
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a = (ea >> 8); // MOV A,EAH
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bc &= 0xff00;
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bc |= a; // MOV C,A
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a = d; // MOV A,D
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// 0345
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ea = (bc >> 8) * a; // MUL B
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ea += (bc & 0xff); // EADD EA, C
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// 0349
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ea >>= 3; // divide by eight
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// 034f
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ff51 = ea; // save scaled pitch LFO
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bc = tos; // pop BC, contains scaling amount
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a = patchRam.vcfLfo << 1; // amount is doubled and stored at ff48
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// 0354
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ea = (bc >> 8) * a; // MUL B
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a = ea >> 8; // MOV A, EAH
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bc = ff4d; // current LFO output
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// 035b
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ea = (bc & 0xff) * a; // MUL C
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d = a; // MOV D,A
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a = ea >> 8; // MOV A, EAH
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bc &= 0xff00;
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bc |= a; // MOV C,A
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a = d; // MOV A,D
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ea = (bc >> 8) * a; // MUL B
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ea += (bc & 0xff); // EADD EA,C
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ea >>= 1; // DSLR A
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ff53 = ea; // save scaled VCF LFO
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goto h03a1;
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h036b:
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ff1e |= 0x08; // set LFO flag
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goto h0323;
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h0370: // calculate holdoff time
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// printf("0370 ");
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ea = ff56; // holdoff time
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bc = attackTable[patchRam.lfoDelay]; // stored at ff58
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// 0379
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ea += bc; // DADD EA,BC
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ff56 = ea; // STEAX (DE) which still holds ff56 from 0x370
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a = ea >> 8; // MOV A, EAH
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if (a & 0xc0) goto h0385; // OFFI A, $C0
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bc &= 0xff; // MOV B, 0
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goto h032d;
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h0385:
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ff1e |= 0x02; // stop predelay flag
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h0388:
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// printf("0388 ");
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ea = ff5a; // envelope speed
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// 038d
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bc = lfoDelayTable[patchRam.lfoDelay >> 4]; // delay setting divided by 8 and saved at ff6c
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// printf("---------------------------------------- %04x %04x\n", ea, bc);
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// 0391 DADDNC EA, BC
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if ((ea + bc) > 0xffff) goto h039a;
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ea += bc;
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// 394
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ff5a = ea; // STEAX (HL) hl still contains ff5a
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bc |= (ea & 0xff00); // MOV A, EAH; MOV B, A
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goto h032d;
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h039a:
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ff1e |= 0x04;
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bc |= 0xff; // MVI B, $ff
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goto h032d;
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h03a1:
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// printf("LFO=%04x VCF=%04x flags=%02x holdoff=%04x envelope=%04x\n", ff51, ff53, ff1e, ff56, ff5a);
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return;
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}
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void Synth::runLFO() {
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// compute a loop's worth of LFO
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