Music code example

Example of code for creating Music on the AY-3-8910

This is Beta version of Code to play music on the Synth Chip.

Code features:

Written in C so portable

While example is controlling the chip with the Z80 PIO, easy to modify for direct access or other port options.

Able to compute values of the Notes based on Clock Frequency supply to chip on

C code:

Notes on code, written to display note information on LCD display, just remove special routines replace with your own or standard out or no display at all.

/* AY-3-8910 Sound Generator *//* 2020 Music Note player */
#include "music_notes.h"#include "Hyundai_256x128.h"#include "Z80_IO.h"#include <z80.h>#include <stdlib.h>#include <string.h>
void int2ascii(unsigned int cx, char *ptr );void LCD_load_Char(void);void system_init(void);void gen_notes( void );
void PSG_write(unsigned char address, unsigned char data);unsigned char PSG_read(unsigned char address);
unsigned char note_table[108][2];float AY_CLK = 2000000.0; // Define AY clock frequency
void delay(int j){int i;for(i=0; i<j; i++);}

int main(){char data[20];char song[32][4] = {"E5","D5","C5","D5","E5","E5","E5","RES","D5","D5","D5","RES","E5","G5","G5","RES","E5","D5","C5","D5","E5","E5","E5","E5","D5","D5","E5","D5","C5","RES","RES","RES"};
int i, k, j;system_init();gen_notes( );
i = 0;k = 0;j = 0;LCD_set_cursor(0, 0);LCD_print( "AY-3-8910 \n" );LCD_set_cursor(0, 1);LCD_print( "Music Notes \n" );

// Reset PSGz80_outp( Z80_PIO_B, 0x00);delay(100);z80_outp( Z80_PIO_B, 0x08);

while (i != 10){i = z80_inp(Z80_PIO_A);

PSG_write(7, 0xfe);k = 0;while( strcmp( music_notes[k], song[j]) != 0 ) k++;

LCD_set_cursor(0, 4);LCD_print( "Note = \n" );
LCD_print( music_notes[k] );LCD_set_cursor(0, 5);LCD_print( "FT = \n" );int2ascii( note_table[k][0], data);LCD_print( data );
LCD_set_cursor(0, 6);LCD_print( "CT = \n" );int2ascii( note_table[k][1], data);LCD_print( data );

LCD_set_cursor(0, 8);LCD_print( "K = \n" );int2ascii( k, data);LCD_print( data );
// Play Noteif (k != 108 ){PSG_write(0, note_table[k][0]); // Channel A low 8-bits of 12 bit valuePSG_write(1, note_table[k][1]); // Channel A High 4-bits of 12 bit value
// Set PSG sound wave, for note sound.PSG_write(0x08, 0x10); // Amplitude Control channel APSG_write(0x09, 0x00); // Amplitude Control channel B PSG_write(0x0a, 0x00); // Amplitude Control channel CPSG_write(0x0b, 0xff); // ENVELOPE ControlPSG_write(0x0c, 0x0f); // ENVELOPE ControlPSG_write(0x0d, 0x00); // ENVELOPE Control wave form}
j++;if (j > 31) j = 0; delay(30000); // Delay between playing next note, adjust for CPU speed if needed add another delay for longer time Delay value in 16 bit intiger

}

LCD_set_cursor(0, 10);LCD_print( "Exit program \n" );return 0;}
void gen_notes( void ) // Calculate values for PSG registers, based on Clock input{int i;long a, b, c;
for( i = 0; i < 108; i++) { a = (long) AY_CLK / (16.0 * music_feq[i]);
b = a / 256; c = a - b * 256; note_table[i][0] = (unsigned char) c;note_table[i][1] = (unsigned char) b; } }

void PSG_write(unsigned char address, unsigned char data)
{// setup Z80_PIO_A_CLT to outputz80_outp( Z80_PIO_A_CTL, Z80_PIO_M0);z80_outp( Z80_PIO_A, address & 0x0f );// Latch addressz80_outp( Z80_PIO_B, 0x0f);// Setup to write dataz80_outp( Z80_PIO_B, 0x08);z80_outp( Z80_PIO_A, data);// Write Dataz80_outp( Z80_PIO_B, 0x0e);z80_outp( Z80_PIO_B, 0x08);// setup Z80_PIO_A_CLT back to input just to be safez80_outp( Z80_PIO_A_CTL, Z80_PIO_M1); }
unsigned char PSG_read(unsigned char address){unsigned char data;// setup Z80_PIO_A_CLT to outputz80_outp( Z80_PIO_A_CTL, Z80_PIO_M0);z80_outp( Z80_PIO_A, address & 0x0f );// Latch addressz80_outp( Z80_PIO_B, 0x0f);// Setup to read dataz80_outp( Z80_PIO_B, 0x08);// Z80 PIO as inputz80_outp( Z80_PIO_A_CTL, Z80_PIO_M1);
z80_outp( Z80_PIO_B, 0x0b);data = z80_inp(Z80_PIO_A);
// Setup to read dataz80_outp( Z80_PIO_B, 0x08);// Z80 PIO as inputz80_outp( Z80_PIO_A_CTL, Z80_PIO_M1);
return data; }

void system_init(void){
// initialize PIO ports
z80_outp( Z80_PIO_A_CTL, Z80_PIO_M1); // set mode 1 byte outputz80_outp( Z80_PIO_B_CTL, Z80_PIO_M0); // set mode 0 output mode z80_outp( Z80_PIO_B, 0x00);
// intialize displayLCD_write_cmd( 0x40 ); // System set commandLCD_write(0x30); // P1 use internal 8px char w/ no top line correctionLCD_write(0x87); // P2 8px width charLCD_write(0x07); // P3 8px height charLCD_write(0x1f); // P4 32 char per lineLCD_write(0x23); // P5 previous value + 4LCD_write(0x7f); // P6 128 pixel screen heightLCD_write(0x20); // P7 32 char per lineLCD_write(0x00); // P8

LCD_write_cmd(0x5d); // Set cursor typeLCD_write(0x04);LCD_write(0x86);LCD_write_cmd(0x4c); // Set direction of cursor movementLCD_write_cmd(0x5B); // Set display overlayLCD_write(0x08); //3

LCD_write_cmd(0x44); //Scroll - Set display start address and display regionsLCD_write(0x00);LCD_write(0x00);LCD_write(0x80);LCD_write(0xb0);LCD_write(0x04);LCD_write(0x80);LCD_write(0x00);LCD_write(0x00);LCD_write(0x80);LCD_write(0xb0);

LCD_write_cmd(0x5A); // Set horizontal scroll LCD_write(0x00);

LCD_write_cmd(0x59); // Display onLCD_write(0x16); // 06
LCD_clear();LCD_graphics_clear();LCD_set_cursor(0, 0);
}

void int2ascii(unsigned int cx, char *ptr ){ int i;ptr = ptr + 5;
*ptr-- = '\0';
for( i = 0; i < 5; i++){*ptr-- = '0' + cx % 10 ;cx = cx / 10;} }

C header file with Musical Notes defined and note frequency

/* music_notes.h *//* Musical Note fequency table for converstion of notes *//* 2/2020 Eric.Stringer@gmail.com */

char music_notes[109][4] = { "C0","C#0","D0","D#0","E0","F0","F#0","G0","G#0","A0","A#0","B0","C1","C#1","D1","D#1","E1","F1","F#1","G1","G#1","A1","A#1","B1","C2","C#2","D2","D#2","E2","F2","F#2","G2","G#2","A2","A#2","B2","C3","C#3","D3","D#3","E3","F3","F#3","G3","G#3","A3","A#3","B3","C4","C#4","D4","D#4","E4","F4","F#4","G4","G#4","A4","A#4","B4","C5","C#5","D5","D#5","E5","F5","F#5","G5","G#5","A5","A#5","B5","C6","C#6","D6","D#6","E6","F6","F#6","G6","G#6","A6","A#6","B6","C7","C#7","D7","D#7","E7","F7","F#7","G7","G#7","A7","A#7","B7","C8","C#8","D8","D#8","E8","F8","F#8","G8","G#8","A8","A#8","B8","RES"};

float music_feq[109]= { 16.35, 17.32, 18.35, 19.45, 20.60, 21.83, 23.12, 24.50, 25.96, 27.50, 29.14, 30.87, 32.70, 34.65, 36.71, 38.89, 41.20, 43.65, 46.25, 49.00, 51.91, 55.00, 58.27, 61.74, 65.41, 69.30, 73.42, 77.78, 82.41, 87.31, 92.50, 98.00, 103.83, 110.00, 116.54, 123.47, 130.81, 138.59, 146.83, 155.56, 164.81, 174.61, 185.00, 196.00, 207.65, 220.00, 233.08, 246.94, 261.63, 277.18, 293.66, 311.13, 329.63, 349.23, 369.99, 392.00, 415.30, 440.00, 466.16, 493.88, 523.25, 554.37, 587.33, 622.25, 659.26, 698.46, 739.99, 783.99, 830.61, 880.00, 932.33, 987.77, 1046.50, 1108.73, 1174.66, 1244.51, 1318.51, 1396.91, 1479.98, 1567.98, 1661.22, 1760.00, 1864.66, 1975.53, 2093.00, 2217.46, 2349.32, 2489.02, 2637.02, 2793.83, 2959.96, 3135.96, 3322.44, 3520.00, 3729.31, 3951.07, 4186.01, 4434.92, 4698.64, 4978.03, 5274.04, 5587.65, 5919.91, 6271.93, 6644.88, 7040.00, 7458.62, 7902.13, 0.0};

Page updated

Google Sites

Report abuse