Files
86Box/src/include/86box/vid_mda.h

149 lines
5.0 KiB
C

/*
* 86Box A hypervisor and IBM PC system emulator that specializes in
* running old operating systems and software designed for IBM
* PC systems and compatibles from 1981 through fairly recent
* system designs based on the PCI bus.
*
* This file is part of the 86Box distribution.
*
* Emulation of the IBM Monochrome Display and Printer card.
*
* Authors: Sarah Walker, starfrost
*
* Copyright 2007-2024 Sarah Walker
* Copyright 2025 Connor Hyde / starfrost, <mario64crashed@gmail.com>
*/
#ifndef VIDEO_MDA_H
#define VIDEO_MDA_H
// Defines
#define MDA_CRTC_NUM_REGISTERS 32
// Enums & structures
typedef enum mda_registers_e
{
MDA_REGISTER_START = 0x3B0,
MDA_REGISTER_CRTC_INDEX = 0x3B4,
MDA_REGISTER_CRTC_DATA = 0x3B5,
MDA_REGISTER_MODE_CONTROL = 0x3B8,
MDA_REGISTER_CRT_STATUS = 0x3BA,
MDA_REGISTER_PARALLEL_DATA = 0x3BC,
MDA_REGISTER_PRINTER_STATUS = 0x3BD,
MDA_REGISTER_PRINTER_CONTROL = 0x3BE,
MDA_REGISTER_END = 0x3BF,
} mda_registers;
// Motorola MC6845 CRTC registers (without light pen for some reason)
typedef enum mda_crtc_registers_e
{
MDA_CRTC_HTOTAL = 0x0, // Horizontal total (total number of characters incl. hsync)
MDA_CRTC_HDISP = 0x1, // Horizontal display
MDA_CRTC_HSYNC_POS = 0x2, // Horizontal position of horizontal ysnc
MDA_CRTC_HSYNC_WIDTH = 0x3, // Width of horizontal sync
MDA_CRTC_VTOTAL = 0x4, // Vertical total (total number of scanlines incl. vsync)
MDA_CRTC_VTOTAL_ADJUST = 0x5, // Vertical total adjust value
MDA_CRTC_VDISP = 0x6, // Vertical display (total number of displayed scanline)
MDA_CRTC_VSYNC = 0x7, // Vertical sync scanline number
MDA_CRTC_INTERLACE = 0x8, // Interlacing mode
MDA_CRTC_MAX_SCANLINE_ADDR = 0x9, // Maximum scanline address
MDA_CRTC_CURSOR_START = 0xA, // Cursor start scanline
MDA_CRTC_CURSOR_END = 0xB, // Cursor end scanline
MDA_CRTC_START_ADDR_HIGH = 0xC, // Screen start address high 8 bits
MDA_CRTC_START_ADDR_LOW = 0xD, // Screen start address low 8 bits
MDA_CRTC_CURSOR_ADDR_HIGH = 0xE, // Cursor address high 8 bits
MDA_CRTC_CURSOR_ADDR_LOW = 0xF, // Cursor address low 8 bits
} mda_crtc_registers;
typedef enum mda_mode_flags_e
{
MDA_MODE_HIGHRES = 1 << 0, // MUST be enabled for sane operation
MDA_MODE_BW = 1 << 1, // UNUSED in most cases. Not present on Hercules
MDA_MODE_VIDEO_ENABLE = 1 << 3,
MDA_MODE_BLINK = 1 << 5,
} mda_mode_flags;
typedef enum mda_colors_e
{
MDA_COLOR_BLACK = 0,
MDA_COLOR_BLUE = 1,
MDA_COLOR_GREEN = 2,
MDA_COLOR_CYAN = 3,
MDA_COLOR_RED = 4,
MDA_COLOR_MAGENTA = 5,
MDA_COLOR_BROWN = 6,
MDA_COLOR_WHITE = 7,
MDA_COLOR_GREY = 8,
MDA_COLOR_BRIGHT_BLUE = 9,
MDA_COLOR_BRIGHT_GREEN = 10,
MDA_COLOR_BRIGHT_CYAN = 11,
MDA_COLOR_BRIGHT_RED = 12,
MDA_COLOR_BRIGHT_MAGENTA = 13,
MDA_COLOR_BRIGHT_YELLOW = 14,
MDA_COLOR_BRIGHT_WHITE = 15,
} mda_colors;
typedef struct mda_t {
mem_mapping_t mapping;
uint8_t crtc[MDA_CRTC_NUM_REGISTERS];
int32_t crtcreg;
uint8_t mode;
uint8_t status;
uint64_t dispontime;
uint64_t dispofftime;
pc_timer_t timer;
int32_t firstline;
int32_t lastline;
int32_t fontbase;
int32_t linepos;
int32_t displine;
int32_t vc;
int32_t scanline;
uint16_t memaddr;
uint16_t memaddr_backup;
int32_t cursorvisible;
int32_t cursoron;
int32_t dispon;
int32_t blink;
int32_t vsynctime;
int32_t vadj;
int32_t monitor_index;
int32_t prev_monitor_index;
int32_t monitor_type; // Used for MDA Colour support (REV0 u64)
uint8_t *vram;
} mda_t;
#define VIDEO_MONITOR_PROLOGUE() \
{ \
mda->prev_monitor_index = monitor_index_global; \
monitor_index_global = mda->monitor_index; \
}
#define VIDEO_MONITOR_EPILOGUE() \
{ \
monitor_index_global = mda->prev_monitor_index; \
}
void mda_init(mda_t *mda);
void mda_setcol(int chr, int blink, int fg, uint8_t cga_ink);
void mda_out(uint16_t addr, uint8_t val, void *priv);
uint8_t mda_in(uint16_t addr, void *priv);
void mda_write(uint32_t addr, uint8_t val, void *priv);
uint8_t mda_read(uint32_t addr, void *priv);
void mda_recalctimings(mda_t *mda);
void mda_poll(void *priv);
#ifdef EMU_DEVICE_H
extern const device_t mda_device;
#endif
#endif /*VIDEO_MDA_H*/