mirror of
https://github.com/V2RetroComputing/analog-firmware.git
synced 2024-10-19 13:25:30 +00:00
282 lines
9.9 KiB
C
282 lines
9.9 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/abus.h"
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#include "vga/businterface.h"
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#include "vga/vgabuf.h"
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volatile uint8_t *terminal_page = terminal_memory;
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void __time_critical_func(vga_businterface)(uint32_t address, uint32_t value) {
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// Shadow parts of the Apple's memory by observing the bus write cycles
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if((address < 0xC000) && ((value & (1u << CONFIG_PIN_APPLEBUS_RW-CONFIG_PIN_APPLEBUS_DATA_BASE)) == 0)) {
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// Apple IIgs: CARD_SELECT is pulled low by our CPLD when M2B0 is active and addr < $C000
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#ifdef ANALOG_GS
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if(CARD_SELECT) {
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private_memory[address] = value & 0xff;
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return;
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}
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#endif
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// Shadow parts of the Apple's memory by observing the bus write cycles
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if(ACCESS_WRITE) {
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// Mirror Video Memory from MAIN & AUX banks
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if(soft_switches & SOFTSW_80STORE) {
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if(soft_switches & SOFTSW_PAGE_2) {
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if((address >= 0x400) && (address < 0x800)) {
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private_memory[address] = value & 0xff;
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return;
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} else if((soft_switches & SOFTSW_HIRES_MODE) && (address >= 0x2000) && (address < 0x4000)) {
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private_memory[address] = value & 0xff;
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return;
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}
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}
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} else if(soft_switches & SOFTSW_AUX_WRITE) {
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if((address >= 0x200) && (address < 0xC000)) {
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private_memory[address] = value & 0xff;
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return;
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}
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}
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if((address >= 0x200) && (address < 0xC000)) {
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apple_memory[address] = value & 0xff;
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return;
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}
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}
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// Shadow the soft-switches by observing all read & write bus cycles
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if((address & 0xff80) == 0xc000) {
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switch(address & 0x7f) {
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case 0x00:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches &= ~SOFTSW_80STORE;
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}
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break;
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case 0x01:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches |= SOFTSW_80STORE;
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}
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break;
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case 0x04:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches &= ~SOFTSW_AUX_WRITE;
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}
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break;
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case 0x05:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches |= SOFTSW_AUX_WRITE;
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}
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break;
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case 0x08:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches &= ~SOFTSW_AUXZP;
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}
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break;
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case 0x09:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches |= SOFTSW_AUXZP;
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}
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break;
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case 0x0c:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches &= ~SOFTSW_80COL;
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}
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break;
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case 0x0d:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches |= SOFTSW_80COL;
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}
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break;
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case 0x0e:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches &= ~SOFTSW_ALTCHAR;
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}
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break;
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case 0x0f:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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soft_switches |= SOFTSW_ALTCHAR;
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}
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break;
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case 0x21:
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if((internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) && ACCESS_WRITE) {
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if(value & 0x80) {
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soft_switches |= SOFTSW_MONOCHROME;
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} else {
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soft_switches &= ~SOFTSW_MONOCHROME;
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}
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}
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break;
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case 0x22:
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if((internal_flags & IFLAGS_IIGS_REGS) && ACCESS_WRITE) {
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apple_tbcolor = value & 0xff;
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}
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break;
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case 0x29:
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if((internal_flags & IFLAGS_IIGS_REGS) && ACCESS_WRITE) {
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soft_switches = (soft_switches & ~(SOFTSW_NEWVID_MASK << SOFTSW_NEWVID_SHIFT)) | ((value & SOFTSW_NEWVID_MASK) << SOFTSW_NEWVID_SHIFT);
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}
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break;
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case 0x34:
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if((internal_flags & IFLAGS_IIGS_REGS) && ACCESS_WRITE) {
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apple_border = value & 0x0f;
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}
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break;
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case 0x35:
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if((internal_flags & IFLAGS_IIGS_REGS) && ACCESS_WRITE) {
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soft_switches = (soft_switches & ~(SOFTSW_SHADOW_MASK << SOFTSW_SHADOW_SHIFT)) | ((value & SOFTSW_SHADOW_MASK) << SOFTSW_SHADOW_SHIFT);
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}
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break;
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case 0x50:
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soft_switches &= ~SOFTSW_TEXT_MODE;
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break;
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case 0x51:
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soft_switches |= SOFTSW_TEXT_MODE;
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break;
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case 0x52:
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soft_switches &= ~SOFTSW_MIX_MODE;
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break;
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case 0x53:
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soft_switches |= SOFTSW_MIX_MODE;
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break;
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case 0x54:
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soft_switches &= ~SOFTSW_PAGE_2;
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break;
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case 0x55:
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soft_switches |= SOFTSW_PAGE_2;
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break;
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case 0x56:
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soft_switches &= ~SOFTSW_HIRES_MODE;
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break;
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case 0x57:
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soft_switches |= SOFTSW_HIRES_MODE;
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break;
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case 0x5e:
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if(internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) {
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soft_switches |= SOFTSW_DGR;
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}
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break;
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case 0x5f:
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if(internal_flags & (IFLAGS_IIGS_REGS | IFLAGS_IIE_REGS)) {
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soft_switches &= ~SOFTSW_DGR;
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}
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break;
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case 0x7e:
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if((internal_flags & IFLAGS_IIE_REGS) && ACCESS_WRITE) {
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soft_switches |= SOFTSW_IOUDIS;
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}
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break;
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case 0x7f:
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if((internal_flags & IFLAGS_IIE_REGS) && ACCESS_WRITE) {
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soft_switches &= ~SOFTSW_IOUDIS;
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}
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break;
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}
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return;
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}
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// Control sequences used by ROMX and ROMXe
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switch(current_machine) {
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case MACHINE_IIE:
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// Trigger on read sequence FACA FACA FAFE
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if(ACCESS_READ) {
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if((address >> 8) == 0xFA) {
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switch(address & 0xFF) {
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case 0xCA:
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romx_unlocked = (romx_unlocked == 1) ? 2 : 1;
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break;
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case 0xFE:
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romx_unlocked = (romx_unlocked == 2) ? 3 : 0;
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break;
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default:
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if(romx_unlocked != 3)
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romx_unlocked = 0;
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break;
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}
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} else if(romx_unlocked == 3) {
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if((address & 0xFFF0) == 0xF810) {
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romx_textbank = address & 0xF;
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}
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if(address == 0xF851) {
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romx_changed = 1;
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romx_unlocked = 0;
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}
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}
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}
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break;
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case MACHINE_II:
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// Trigger on read sequence CACA CACA CAFE
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if(ACCESS_READ) {
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if((address >> 8) == 0xCA) {
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switch(address & 0xFF) {
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case 0xCA:
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romx_unlocked = (romx_unlocked == 1) ? 2 : 1;
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break;
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case 0xFE:
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romx_unlocked = (romx_unlocked == 2) ? 3 : 0;
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break;
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default:
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if(romx_unlocked != 3)
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romx_unlocked = 0;
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break;
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}
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} else if(romx_unlocked == 3) {
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if((address & 0xFFF0) == 0xCFD0) {
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romx_textbank = address & 0xF;
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}
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if((address & 0xFFF0) == 0xCFE0) {
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romx_changed = 1;
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romx_unlocked = 0;
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}
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}
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}
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break;
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}
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// Card Registers
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if(ACCESS_WRITE) {
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if(CARD_SELECT && CARD_DEVSEL) {
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cardslot = (address >> 4) & 0x7;
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switch(address & 0x0F) {
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case 0x01:
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mono_palette = (value >> 4) & 0xF;
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if(value & 0x8) {
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internal_flags |= IFLAGS_OLDCOLOR;
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} else {
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internal_flags &= ~IFLAGS_OLDCOLOR;
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}
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apple_memory[address] = value;
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break;
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case 0x02:
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terminal_tbcolor = value & 0xff;
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apple_memory[address] = terminal_tbcolor;
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break;
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case 0x03:
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terminal_border = value & 0x0f;
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apple_memory[address] = terminal_border;
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break;
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case 0x08:
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soft_switches &= ~SOFTSW_TERMINAL;
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break;
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case 0x09:
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soft_switches |= SOFTSW_TERMINAL;
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break;
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case 0x0A:
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terminal_fifo[terminal_fifo_wrptr++] = (value & 0xFF);
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apple_memory[address] = (terminal_fifo_rdptr - terminal_fifo_wrptr);
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break;
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case 0x0B:
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if((value & 0xFF) <= 0x27) {
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romx_textbank = (value & 0xFF);
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romx_changed = 1;
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}
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break;
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}
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}
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} else if(CARD_SELECT && CARD_DEVSEL) {
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if((address & 0x0F) == 0x0A) {
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apple_memory[address] = (terminal_fifo_rdptr - terminal_fifo_wrptr);
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}
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}
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}
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