73 lines
1.8 KiB
C
73 lines
1.8 KiB
C
#include <string.h>
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#include <hardware/pio.h>
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#include "common/config.h"
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#include "common/buffers.h"
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#include "common/abus.h"
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#include "z80/businterface.h"
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#include "z80/z80buf.h"
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volatile uint8_t *pcpi_reg = apple_memory + 0xC0C0;
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static inline void __time_critical_func(pcpi_read)(uint32_t address) {
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switch(address & 0x7) {
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case 0: // Read Data from Z80
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clr_6502_stat;
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break;
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case 5: // Z80 Reset
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z80_res = 1;
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break;
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case 6: // Z80 INT
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//z80_irq = 1;
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break;
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case 7: // Z80 NMI
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z80_nmi = 1;
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break;
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}
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}
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static inline void __time_critical_func(pcpi_write)(uint32_t address, uint32_t value) {
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switch(address & 0x7) {
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case 0:
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case 2:
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case 3:
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case 4:
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break;
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case 1: // Write Data to Z80
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pcpi_reg[1] = value & 0xff;
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set_z80_stat;
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break;
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case 5:
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case 6:
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case 7:
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pcpi_read(address);
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break;
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}
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}
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void __time_critical_func(z80_businterface)(uint32_t address, uint32_t value) {
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volatile uint8_t *new_pcpi_reg;
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// Reset the Z80 when the Apple II resets
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if(reset_state == 3) z80_res = 1;
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// Shadow parts of the Apple's memory by observing the bus write cycles
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if(CARD_SELECT) {
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if(CARD_DEVSEL) {
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// Ideally this code should only run once.
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new_pcpi_reg = apple_memory + (address & 0xFFF0);
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if((uint32_t)new_pcpi_reg != (uint32_t)pcpi_reg) {
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memcpy(new_pcpi_reg, pcpi_reg, 16);
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pcpi_reg = new_pcpi_reg;
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}
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if((value & (1u << CONFIG_PIN_APPLEBUS_RW-CONFIG_PIN_APPLEBUS_DATA_BASE)) == 0) {
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pcpi_write(address, value);
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} else {
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pcpi_read(address);
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}
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}
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}
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}
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