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https://github.com/libretro/NP2kai.git
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100 lines
2.3 KiB
C
Executable File
100 lines
2.3 KiB
C
Executable File
#include <compiler.h>
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#include <cpucore.h>
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#include <pccore.h>
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#include <io/iocore.h>
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#include <bios/bios.h>
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#include <bios/biosmem.h>
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#include "rsbios.h"
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void bios0x0c(void) {
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UINT16 doff;
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UINT16 dseg;
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REG8 flag;
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UINT8 data;
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UINT8 status;
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REG16 pos;
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REG16 cnt;
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doff = GETBIOSMEM16(MEMW_RS_CH0_OFST);
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dseg = GETBIOSMEM16(MEMW_RS_CH0_SEG);
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flag = MEMR_READ8(dseg, doff + R_FLAG);
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data = iocore_inp8(0x30); // データ引き取り
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status = iocore_inp8(0x32) & 0xfc; // ステータス
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status |= (iocore_inp8(0x33) & 3);
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#if 0
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if (status & 0x38) {
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iocore_out8(0x32, flag | 0x10);
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}
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#endif
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if (!(flag & RFLAG_BFULL)) {
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// SI/SO変換
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if (mem[MEMB_RS_S_FLAG] & 0x80) {
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if (data >= 0x20) {
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if (mem[MEMB_RS_S_FLAG] & 0x10) {
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data |= 0x80;
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}
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else {
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data &= 0x7f;
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}
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}
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else if (data == RSCODE_SO) {
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mem[MEMB_RS_S_FLAG] |= 0x10;
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iocore_out8(0x00, 0x20);
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return;
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}
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else if (data == RSCODE_SI) {
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mem[MEMB_RS_S_FLAG] &= ~0x10;
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iocore_out8(0x00, 0x20);
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return;
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}
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}
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// DELコードの扱い
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if (mem[MEMB_RS_D_FLAG] & 0x01) { // CH0 -> bit0
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if (((data & 0x7f) == 0x7f) && (mem[MEMB_MSW3] & 0x80)) {
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data = 0;
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}
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}
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// データ投棄
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pos = MEMR_READ16(dseg, doff + R_PUTP);
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MEMR_WRITE16(dseg, pos, (UINT16)((data << 8) | status));
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// 次のポインタをストア
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pos = (UINT16)(pos + 2);
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if (pos >= MEMR_READ16(dseg, doff + R_TAILP)) {
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pos = MEMR_READ16(dseg, doff + R_HEADP);
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}
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MEMR_WRITE16(dseg, doff + R_PUTP, pos);
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// カウンタのインクリメント
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cnt = (UINT16)(MEMR_READ16(dseg, doff + R_CNT) + 1);
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MEMR_WRITE16(dseg, doff + R_CNT, cnt);
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// オーバーフローを見張る
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if (pos == MEMR_READ16(dseg, doff + R_GETP)) {
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flag |= RFLAG_BFULL;
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}
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// XOFFを送信？
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if (((flag & (RFLAG_XON | RFLAG_XOFF)) == RFLAG_XON) &&
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(cnt >= MEMR_READ16(dseg, doff + R_XON))) {
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iocore_out8(0x30, RSCODE_XOFF);
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flag |= RFLAG_XOFF;
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}
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}
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else {
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MEMR_WRITE8(dseg, doff + R_CMD,
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(REG8)(MEMR_READ8(dseg, doff + R_CMD) | RFLAG_BOVF));
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}
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MEMR_WRITE8(dseg, doff + R_INT,
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(REG8)(MEMR_READ8(dseg, doff + R_INT) | RINT_INT));
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MEMR_WRITE8(dseg, doff + R_FLAG, flag);
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iocore_out8(0x00, 0x20);
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}
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