kopia lustrzana https://github.com/Jean-MarcHarvengt/MCUME
298 wiersze
9.1 KiB
C
298 wiersze
9.1 KiB
C
#include "shared.h"
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/* VDP context */
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t_vdp vdp;
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/* Return values from the V counter */
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byte vcnt[0x200] =
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{
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
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0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
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0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
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0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
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0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
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0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
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0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
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0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
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0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
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0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
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0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
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0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
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0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
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0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA,
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0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
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0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
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0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF,
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};
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/* Return values from the H counter */
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byte hcnt[0x200] =
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{
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
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0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
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0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
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0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
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0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
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0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
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0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
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0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
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0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
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0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
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0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
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0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
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0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
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0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
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0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9,
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0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
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0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
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0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
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0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
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0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
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0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
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0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF,
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};
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/*--------------------------------------------------------------------------*/
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/* Initialize VDP emulation */
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void vdp_init(void)
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{
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vdp_reset();
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}
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/* Reset VDP emulation */
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void vdp_reset(void)
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{
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memset(&vdp, 0, sizeof(t_vdp));
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vdp.limit = 1;
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}
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/* Write data to the VDP's control port */
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void vdp_ctrl_w(int data)
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{
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/* Waiting for the reset of the command? */
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if(vdp.pending == 0)
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{
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/* Save data for later */
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vdp.latch = data;
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/* Set pending flag */
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vdp.pending = 1;
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}
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else
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{
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/* Clear pending flag */
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vdp.pending = 0;
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/* VDP register write */
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if((data & 0xF0) == 0x80)
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{
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int r = (data & 0x0F);
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int d = vdp.latch;
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/* Store register data */
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vdp.reg[r] = d;
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/* Update table addresses */
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vdp.ntab = (vdp.reg[2] << 10) & 0x3800;
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vdp.satb = (vdp.reg[5] << 7) & 0x3F00;
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vdp.addr = vdp.code = 0;
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}
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else
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{
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/* Extract code bits */
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vdp.code = (data >> 6) & 3;
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/* Make address */
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vdp.addr = (data << 8 | vdp.latch);
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/* Read VRAM for code 0x00 */
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if(vdp.code == 0x00)
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{
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/* Load buffer with current VRAM byte */
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vdp.buffer = vdp.vram[(vdp.addr & 0x3FFF)];
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/* Bump address */
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vdp.addr += 1;
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}
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}
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}
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}
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/* Read the status flags */
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int vdp_ctrl_r(void)
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{
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/* Save the status flags */
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byte temp = vdp.status;
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/* Clear pending flag */
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vdp.pending = 0;
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/* Clear pending interrupt and sprite collision flags */
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vdp.status &= ~(0x80 | 0x40 | 0x20);
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/* Lower the IRQ line */
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if(sms.irq == 1)
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{
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sms.irq = 0;
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z80_set_irq_line(0, CLEAR_LINE);
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}
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/* Return the old status flags */
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return (temp);
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}
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/* Write data to the VDP's data port */
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void vdp_data_w(int data)
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{
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int index;
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/* Clear the pending flag */
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vdp.pending = 0;
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switch(vdp.code)
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{
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case 0: /* VRAM write */
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case 1: /* VRAM write */
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case 2: /* VRAM write */
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/* Get current address in VRAM */
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index = (vdp.addr & 0x3FFF);
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/* Only update if data is new */
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if(data != vdp.vram[index])
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{
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/* Store VRAM byte */
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vdp.vram[index] = data;
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/* Mark patterns as dirty */
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svram_dirty[(index >> 5)] = sis_vram_dirty = 1;
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}
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break;
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case 3: /* CRAM write */
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if(cart.type == TYPE_GG)
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{
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index = (vdp.addr & 0x3F);
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if(data != vdp.cram[index])
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{
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vdp.cram[index] = data;
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index = (vdp.addr >> 1) & 0x1F;
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palette_sync(index);
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}
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}
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else
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{
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index = (vdp.addr & 0x1F);
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if(data != vdp.cram[index])
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{
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vdp.cram[index] = data;
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palette_sync(index);
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}
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}
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break;
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}
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/* Bump the VRAM address */
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vdp.addr += 1;
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}
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/* Read data from the VDP's data port */
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int vdp_data_r(void)
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{
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byte temp = 0;
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/* Clear the pending flag */
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vdp.pending = 0;
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switch(vdp.code)
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{
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case 0: /* VRAM read */
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case 1: /* VRAM read */
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case 2: /* VRAM read */
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/* Return the buffered value */
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temp = vdp.buffer;
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/* Get data from the current VRAM address */
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vdp.buffer = vdp.vram[(vdp.addr & 0x3FFF)];
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break;
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case 3: /* Undefined */
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/* Return 'no value' data */
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temp = 0xFF;
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break;
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}
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/* Bump address register */
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vdp.addr += 1;
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return (temp);
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}
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/* Process frame events */
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void vdp_run(void)
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{
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if(vdp.line <= 0xC0)
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{
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if(vdp.line == 0xC0)
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{
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vdp.status |= 0x80;
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}
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if(vdp.line == 0)
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{
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vdp.left = vdp.reg[10];
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}
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if(vdp.left == 0)
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{
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vdp.left = vdp.reg[10];
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vdp.status |= 0x40;
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}
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else
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{
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vdp.left -= 1;
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}
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if((vdp.status & 0x40) && (vdp.reg[0] & 0x10))
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{
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sms.irq = 1;
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z80_set_irq_line(0, ASSERT_LINE);
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}
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}
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else
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{
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vdp.left = vdp.reg[10];
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if((vdp.line < 0xE0) && (vdp.status & 0x80) && (vdp.reg[1] & 0x20))
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{
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sms.irq = 1;
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z80_set_irq_line(0, ASSERT_LINE);
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}
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}
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}
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byte vdp_vcounter_r(void)
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{
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return (vcnt[(vdp.line & 0x1FF)]);
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}
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byte vdp_hcounter_r(void)
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{
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int pixel = (((z80_ICount % CYCLES_PER_LINE) / 4) * 3) * 2;
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return (hcnt[((pixel >> 1) & 0x1FF)]);
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}
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