mirror of
https://github.com/JorjBauer/aiie.git
synced 2024-12-27 14:30:22 +00:00
removed more unnecessary audio files...
This commit is contained in:
Jorj Bauer
parent
5d85c2204a
commit
5f3c513d61
2
Makefile
2
Makefile
@ -6,7 +6,7 @@ CXXFLAGS=-Wall -I .. -I . -I apple -I sdl -I/usr/local/include/SDL2 -O3 -g
|
||||
|
||||
TSRC=cpu.cpp util/testharness.cpp
|
||||
|
||||
COMMONOBJS=cpu.o apple/appledisplay.o apple/applekeyboard.o apple/applemmu.o apple/applevm.o apple/diskii.o apple/nibutil.o RingBuffer.o globals.o apple/parallelcard.o apple/fx80.o apple/sy6522.o apple/ay8910.o lcg.o
|
||||
COMMONOBJS=cpu.o apple/appledisplay.o apple/applekeyboard.o apple/applemmu.o apple/applevm.o apple/diskii.o apple/nibutil.o RingBuffer.o globals.o apple/parallelcard.o apple/fx80.o lcg.o
|
||||
|
||||
SDLOBJS=sdl/sdl-speaker.o sdl/sdl-display.o sdl/sdl-keyboard.o sdl/sdl-paddles.o sdl/sdl-filemanager.o sdl/aiie.o sdl/sdl-printer.o sdl/sdl-clock.o
|
||||
|
||||
|
||||
374
apple/ay8910.cpp
374
apple/ay8910.cpp
@ -1,374 +0,0 @@
|
||||
#include "ay8910.h"
|
||||
#include <stdio.h>
|
||||
|
||||
#include "globals.h"
|
||||
|
||||
// Map our linear 4-bit amplitude to 8-bit output level
|
||||
static const uint8_t volumeLevels[16] = { 0x00, 0x04, 0x05, 0x07,
|
||||
0x0B, 0x10, 0x16, 0x23,
|
||||
0x2B, 0x44, 0x5A, 0x73,
|
||||
0x92, 0xB0, 0xD9, 0xFF };
|
||||
|
||||
// Envelope constants
|
||||
enum {
|
||||
AY_ENV_HOLD = 1,
|
||||
AY_ENV_ALT = 2,
|
||||
AY_ENV_ATTACK = 4,
|
||||
AY_ENV_CONT = 8
|
||||
};
|
||||
|
||||
/* Envelope handling
|
||||
* (Per General Instruments AY-3-8910 documentation.)
|
||||
*
|
||||
* Envelope period is set in the 16-bit value r[0x0C]:r[0x0B] (where 0 = 1).
|
||||
* The resulting frequency is from 0.12Hz to 7812.5 Hz.
|
||||
*
|
||||
* The shape of the envelope is selected by r[0x0D] and uses the
|
||||
* constants above.
|
||||
*
|
||||
* If AY_ENV_HOLD is set, then when the envelope reaches terminal (0
|
||||
* or 15) it stays there.
|
||||
*
|
||||
* If AY_ENV_ALT is set, the direction reverses each time it reaches
|
||||
* terminal. (If both AY_ENV_HOLD and AY_ENV_ALT are set, then the
|
||||
* envelope counter returns to its initial count before holding.)
|
||||
*
|
||||
* If AY_ENV_ATTACK is set, the counter is ascending (0-to-15); otherwise
|
||||
* it is descending (15-to-0).
|
||||
*
|
||||
* If AY_ENV_CONT is *clear* (0), then the counter resets to 0 after
|
||||
* one cycle and holds there. If it is 1, it does whatever HOLD
|
||||
* says. (So AY_ENV_CONT==0 takes priority over AY_ENV_HOLD).
|
||||
*
|
||||
*
|
||||
*/
|
||||
|
||||
AY8910::AY8910() : lcg(0)
|
||||
{
|
||||
Reset();
|
||||
}
|
||||
|
||||
void AY8910::Reset()
|
||||
{
|
||||
curRegister = 0;
|
||||
|
||||
// FIXME: what are the right default values?
|
||||
for (uint8_t i=0; i<16; i++)
|
||||
r[i] = 0x00;
|
||||
waveformFlipTimer[0] = waveformFlipTimer[1] = waveformFlipTimer[2] = 0;
|
||||
outputState[0] = outputState[1] = outputState[2] = 0;
|
||||
envCounter = 0;
|
||||
envelopeTimer = envelopeTime = 0;
|
||||
envDirection = 1;
|
||||
noiseFlipTimer = 0;
|
||||
noiseFlag = true;
|
||||
|
||||
lcgBitsRemaining = 0;
|
||||
|
||||
#if 0
|
||||
// Debugging
|
||||
r[ENV_PERIOD_COARSE] = 0xFF;
|
||||
r[ENV_PERIOD_FINE] = 0xFF;
|
||||
envelopeTimer = 1;
|
||||
envelopeTime = calculateEnvelopeTime();
|
||||
r[ENV_SHAPE] = 0x08; // sawtooth, descending
|
||||
if (r[ENV_SHAPE] & AY_ENV_ATTACK) {
|
||||
// rising
|
||||
envDirection = 1;
|
||||
envCounter = 0;
|
||||
} else {
|
||||
// falling
|
||||
envDirection = -1;
|
||||
envCounter = 15;
|
||||
}
|
||||
#endif
|
||||
}
|
||||
|
||||
uint8_t AY8910::read(uint8_t reg)
|
||||
{
|
||||
// FIXME: does anything ever need to read from this?
|
||||
return 0xFF;
|
||||
}
|
||||
|
||||
// reg represents BC1, BDIR, /RST in bits 0, 1, 2.
|
||||
// val is the state of those three bits.
|
||||
// PortA is the state of whatever's currently on PortA when we do it.
|
||||
void AY8910::write(uint8_t reg, uint8_t PortA)
|
||||
{
|
||||
// Bit 2 (1 << 2 == 0x04) is wired to the Reset pin. If it goes low,
|
||||
// we reset the virtual chip.
|
||||
if ((reg & NRSET) == 0) {
|
||||
Reset();
|
||||
return;
|
||||
}
|
||||
|
||||
// Bit 0 (1 << 0 == 0x01) is the BC1 pin. BC2 is hard-wired to +5v.
|
||||
// We can ignore bit 3, b/c that was just checked above & triggered
|
||||
// a reset.
|
||||
reg &= ~0x04;
|
||||
|
||||
switch (reg) {
|
||||
case IAB: // bDir==0 && BC1 == 0 (IAB)
|
||||
// Puts the DA bus in high-impedance state. Nothing for us to do?
|
||||
return;
|
||||
case DTB: // bDir==0 && BC1 == 1 (DTB)
|
||||
// Contents of the currently addressed register are put in DA. FIXME?
|
||||
return;
|
||||
case DWS: // bDir==1 && BC1 == 0 (DWS)
|
||||
// Write current PortA to PSG
|
||||
r[curRegister] = PortA;
|
||||
|
||||
if (curRegister <= CHAN_A_COARSE) {
|
||||
// FIXME: for all of A/B/C changes, figure out how much time had
|
||||
// elapsed on the previous timer and apply it to the new one
|
||||
cycleTime[0] = cycleTimeForPSG(0);
|
||||
waveformFlipTimer[0] = g_cpu->cycles + cycleTime[0];
|
||||
} else if (curRegister <= CHAN_B_COARSE) {
|
||||
cycleTime[1] = cycleTimeForPSG(1);
|
||||
waveformFlipTimer[1] = g_cpu->cycles + cycleTime[1];
|
||||
} else if (curRegister <= CHAN_C_COARSE) {
|
||||
cycleTime[2] = cycleTimeForPSG(2);
|
||||
waveformFlipTimer[2] = g_cpu->cycles + cycleTime[2];
|
||||
} else if (curRegister == ENAB) {
|
||||
if (r[ENAB] & ENAB_N_TONEA) {
|
||||
cycleTime[0] = waveformFlipTimer[0] = 0;
|
||||
} else {
|
||||
cycleTime[0] = cycleTimeForPSG(0);
|
||||
waveformFlipTimer[0] = g_cpu->cycles + cycleTime[0];
|
||||
}
|
||||
if (r[ENAB] & ENAB_N_TONEB) {
|
||||
cycleTime[1] = waveformFlipTimer[1] = 0;
|
||||
} else {
|
||||
cycleTime[1] = cycleTimeForPSG(1);
|
||||
waveformFlipTimer[1] = g_cpu->cycles + cycleTime[1];
|
||||
}
|
||||
if (r[ENAB] & ENAB_N_TONEC) {
|
||||
cycleTime[2] = waveformFlipTimer[2] = 0;
|
||||
} else {
|
||||
cycleTime[2] = cycleTimeForPSG(2);
|
||||
waveformFlipTimer[2] = g_cpu->cycles + cycleTime[2];
|
||||
}
|
||||
} else if (curRegister >= ENV_PERIOD_FINE && curRegister <= ENV_PERIOD_COARSE) {
|
||||
// Envelope control -- period or shape
|
||||
// FIXME: should envCounter be initialized to the start position?
|
||||
envelopeTime = calculateEnvelopeTime();
|
||||
envelopeTimer = 0; // reset so it will pick up @ next tick
|
||||
} else if (curRegister == ENV_SHAPE) {
|
||||
if (r[ENV_SHAPE] & AY_ENV_ATTACK) {
|
||||
// rising
|
||||
envDirection = 1;
|
||||
envCounter = 0;
|
||||
} else {
|
||||
// falling
|
||||
envDirection = -1;
|
||||
envCounter = 15;
|
||||
}
|
||||
} else if (curRegister == NOISE_PERIOD) {
|
||||
noiseFlipTimer = g_cpu->cycles + cycleTimeForNoise();
|
||||
}
|
||||
return;
|
||||
case INTAK: // bDir==1 && BC1 == 1 (INTAK)
|
||||
// Select current register
|
||||
curRegister = PortA & 0xF;
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
// The lowest frequency the AY8910 makes is 30.6 Hz, which is ~33431
|
||||
// clock cycles.
|
||||
//
|
||||
// The highest frequency produced is 125kHz, which is ~8 cycles.
|
||||
//
|
||||
// The highest practicable, given our 24-cycle-main-loop, is
|
||||
// 41kHz. Which should be plenty fine.
|
||||
//
|
||||
// Conversely: we should be able to call update() as slowly as once
|
||||
// every 60-ish clock cycles before we start noticing it in the output
|
||||
// audio.
|
||||
uint16_t AY8910::cycleTimeForPSG(uint8_t psg)
|
||||
{
|
||||
// Convert the current registers in to a cycle count for how long
|
||||
// between flips of 0-to-1 from the square wave generator.
|
||||
|
||||
uint16_t regVal = (r[1+(psg*2)] << 8) | (r[0 + (psg*2)]);
|
||||
if (regVal == 0) regVal++;
|
||||
|
||||
// Ft = 4MHz / (32 * regVal); our clock is 1MHz
|
||||
// so we should return (32 * regVal) / 4 ?
|
||||
|
||||
return (32 * regVal) / 4;
|
||||
}
|
||||
|
||||
uint16_t AY8910::cycleTimeForNoise()
|
||||
{
|
||||
uint8_t regval = r[NOISE_PERIOD];
|
||||
if (regval == 0) regval++;
|
||||
|
||||
return (512 * regval) / 4;
|
||||
}
|
||||
|
||||
// Similar calculation: this one, for the envelope timer.
|
||||
// FIXME: I *think* this is right. Not sure. Needs validation.
|
||||
uint32_t AY8910::calculateEnvelopeTime()
|
||||
{
|
||||
uint32_t regVal = (r[ENV_PERIOD_COARSE] << 8) | (r[ENV_PERIOD_FINE]);
|
||||
if (regVal == 0) regVal++;
|
||||
|
||||
// This constant is wrong by about 2%. But it should be fast b/c
|
||||
// powers of 2.
|
||||
return (32 * regVal) / 4;
|
||||
}
|
||||
|
||||
void AY8910::update(uint32_t cpuCycleCount)
|
||||
{
|
||||
#if 0
|
||||
// Debugging: print state of the 16 registers
|
||||
printf("AY8910: ");
|
||||
for (int i=0; i<16; i++) {
|
||||
printf("%02X ", r[i]);
|
||||
}
|
||||
printf("%04X %04X %04X\n", cycleTime[0], cycleTime[1], cycleTime[2]);
|
||||
#endif
|
||||
|
||||
// update the envelope timer if it's time
|
||||
if (envelopeTime != 0) {
|
||||
if (!envelopeTimer) {
|
||||
// timer wasn't set, so start it running
|
||||
envelopeTimer = cpuCycleCount + envelopeTime;
|
||||
}
|
||||
if (envelopeTimer <= cpuCycleCount) {
|
||||
// time to update the envelopeCounter.
|
||||
|
||||
envCounter += envDirection;
|
||||
|
||||
switch (r[ENV_SHAPE]) {
|
||||
// Continue / Attack / Alternate / Hold bits
|
||||
case 0x00: // 0 / 0 / x / x -- descend once, stay @ bottom
|
||||
case 0x01: // 0 / 0 / x / x
|
||||
case 0x02: // 0 / 0 / x / x
|
||||
case 0x03: // 0 / 0 / x / x
|
||||
case 0x04: // 0 / 1 / x / x -- ascend once, jump to bottom
|
||||
case 0x05: // 0 / 1 / x / x
|
||||
case 0x06: // 0 / 1 / x / x
|
||||
case 0x07: // 0 / 1 / x / x
|
||||
case 0x09: // 1 / 0 / 0 / 1 -- descend once, stay @ bottom
|
||||
case 0x0b: // 1 / 0 / 1 / 1 -- descend once, jump to top
|
||||
case 0x0d: // 1 / 1 / 0 / 1 -- ascend once, stay @ top
|
||||
case 0x0f: // 1 / 1 / 1 / 1 -- ascend once, jump to bottom
|
||||
|
||||
// In all these cases, we go from start to finish once. In all
|
||||
// cases except 0x0b and 0x0d, when we're done, we go low.
|
||||
|
||||
if (envDirection > 0) {
|
||||
// We were ascending: did we hit 15? If so, stop & go terminal
|
||||
if (envCounter == 15) {
|
||||
envDirection = 0;
|
||||
// One ascending case (0x0b) goes high after; all others are low
|
||||
envCounter = (r[ENV_SHAPE] == 0x0b ? 0x0F : 0x00);
|
||||
}
|
||||
} else if (envDirection < 0) {
|
||||
// We were descending: did we hit 0? If so, stop & go terminal
|
||||
if (envCounter == 0) {
|
||||
envDirection = 0;
|
||||
// One descending case (0x0d) goes high after; all others are low
|
||||
envCounter = (r[ENV_SHAPE] == 0x0d ? 0x0F : 0x00);
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case 0x08:
|
||||
case 0x0C:
|
||||
// These two jump back to the start when they get to the end.
|
||||
|
||||
if (envCounter > 15) {
|
||||
envCounter = 0;
|
||||
} else if (envCounter < 0) {
|
||||
envCounter = 15;
|
||||
}
|
||||
break;
|
||||
|
||||
case 0x0A:
|
||||
case 0x0E:
|
||||
break;
|
||||
// These two reverse direction.
|
||||
if (envCounter == 15 || envCounter == 0) {
|
||||
envDirection = -envDirection;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
// Set up the envelope timer for the next transition
|
||||
// FIXME: can set this to 0 if envDirection is 0, but have to be careful about setup of timer again when envDirection is re-set
|
||||
envelopeTimer += envelopeTime;
|
||||
}
|
||||
}
|
||||
|
||||
// For the noise timer: if it expires, we get another random bit
|
||||
if (noiseFlipTimer && noiseFlipTimer <= cpuCycleCount) {
|
||||
// FIXME: srnd() this somewhere when we initialized? Does it matter?
|
||||
|
||||
if (!lcgBitsRemaining) {
|
||||
lcgBitsRemaining = 8;
|
||||
lcgLastByte = lcg.rnd();
|
||||
}
|
||||
noiseFlag = lcgLastByte & 1;
|
||||
lcgLastByte >>= 1;
|
||||
lcgBitsRemaining--;
|
||||
}
|
||||
|
||||
#if 0
|
||||
// DEBUGGING ENVELOPES: just output the envelope
|
||||
g_speaker->mixOutput(volumeLevels[envCounter]);
|
||||
return;
|
||||
#endif
|
||||
|
||||
// For any waveformFlipTimer that is > 0: if cpuCycleCount is larger
|
||||
// than the timer, we'll flip state. (It's a square wave!)
|
||||
|
||||
for (uint8_t i=0; i<3; i++) {
|
||||
uint32_t cc = cycleTime[i];
|
||||
|
||||
if (cc) {
|
||||
if (waveformFlipTimer[i] <= cpuCycleCount) {
|
||||
// flip when it's time to flip
|
||||
waveformFlipTimer[i] += cc;
|
||||
outputState[i] = !outputState[i];
|
||||
}
|
||||
} else {
|
||||
outputState[i] = 0;
|
||||
}
|
||||
|
||||
// Figure out what output comes from this channel and send it to
|
||||
// the speaker. The output is controlled by outputState[i] (from
|
||||
// the square wave, above); the amplitude control line for this
|
||||
// output (r[i+8], below) and the tone/noise selection.
|
||||
|
||||
uint8_t amplitude = 0;
|
||||
// If we're trying to output "high" this square-wave cycle, and if
|
||||
// the ToneEnable bit is set for this register, then generate
|
||||
// output.
|
||||
if (!(r[ENAB] & (1 << i)) && outputState[i]) {
|
||||
amplitude = r[i+8] & 0xF;
|
||||
// ... and if bit 0x10 is on, it's modified by the envelope counter.
|
||||
if (r[i+8] & 0x10)
|
||||
amplitude = envCounter;
|
||||
}
|
||||
|
||||
// test the NoiseEnable bit for this register
|
||||
if (!(r[ENAB] & (1 << (3+i)))) {
|
||||
// FIXME: if the noiseFlag is off, do we keep the tone value
|
||||
// above? Or set to 0?
|
||||
if (noiseFlag) {
|
||||
amplitude = 7; // median "0-value" level (fixme?)
|
||||
// ... and if bit 0x10 is on, it's modified by the envelope counter.
|
||||
if (r[i+8] & 0x10)
|
||||
amplitude = envCounter >> 1;
|
||||
} else {
|
||||
amplitude = 0;
|
||||
}
|
||||
}
|
||||
|
||||
g_speaker->mixOutput(volumeLevels[amplitude]);
|
||||
}
|
||||
}
|
||||
|
||||
@ -1,78 +0,0 @@
|
||||
#ifndef __AY8910_H
|
||||
#define __AY8910_H
|
||||
|
||||
#include <stdint.h>
|
||||
#include "lcg.h"
|
||||
|
||||
// Operations...
|
||||
enum {
|
||||
IAB = 0,
|
||||
DTB = 1,
|
||||
DWS = 2,
|
||||
INTAK = 3,
|
||||
NRSET = 4
|
||||
};
|
||||
|
||||
// Registers...
|
||||
enum {
|
||||
CHAN_A_FINE = 0,
|
||||
CHAN_A_COARSE = 1,
|
||||
CHAN_B_FINE = 2,
|
||||
CHAN_B_COARSE = 3,
|
||||
CHAN_C_FINE = 4,
|
||||
CHAN_C_COARSE = 5,
|
||||
NOISE_PERIOD = 6,
|
||||
ENAB = 7,
|
||||
CHAN_A_AMP = 8,
|
||||
CHAN_B_AMP = 9,
|
||||
CHAN_C_AMP = 10,
|
||||
ENV_PERIOD_FINE = 11,
|
||||
ENV_PERIOD_COARSE = 12,
|
||||
ENV_SHAPE = 13
|
||||
};
|
||||
|
||||
// Enable flags (all negative; enabled-low)
|
||||
enum {
|
||||
ENAB_N_TONEA = 1,
|
||||
ENAB_N_TONEB = 2,
|
||||
ENAB_N_TONEC = 4,
|
||||
ENAB_N_NOISEA = 8,
|
||||
ENAB_N_NOISEB = 16,
|
||||
ENAB_N_NOISEC = 32
|
||||
};
|
||||
|
||||
class AY8910 {
|
||||
public:
|
||||
AY8910();
|
||||
|
||||
void Reset();
|
||||
|
||||
uint8_t read(uint8_t reg);
|
||||
void write(uint8_t reg, uint8_t PortA);
|
||||
|
||||
void update(uint32_t cpuCycleCount);
|
||||
|
||||
protected:
|
||||
uint16_t cycleTimeForPSG(uint8_t psg);
|
||||
uint16_t cycleTimeForNoise();
|
||||
uint32_t calculateEnvelopeTime();
|
||||
|
||||
private:
|
||||
uint8_t curRegister;
|
||||
uint8_t r[16];
|
||||
uint16_t cycleTime[3]; // how long each cycle will last, in clock cycles
|
||||
uint32_t waveformFlipTimer[3]; // when we're going to flip next
|
||||
uint8_t outputState[3];
|
||||
int8_t envCounter; // which bit of the waveform the envelope is on
|
||||
int8_t envDirection;
|
||||
uint32_t envelopeTime;
|
||||
uint32_t envelopeTimer;
|
||||
uint32_t noiseFlipTimer;
|
||||
bool noiseFlag;
|
||||
|
||||
LCG lcg;
|
||||
uint8_t lcgLastByte;
|
||||
uint8_t lcgBitsRemaining;
|
||||
};
|
||||
|
||||
#endif
|
||||
@ -1 +0,0 @@
|
||||
../apple/ay8910.cpp
|
||||
@ -1 +0,0 @@
|
||||
../apple/ay8910.h
|
||||
Loading…
Reference in New Issue
Block a user