Added initial (and a bit buggy on OS/2, so use 8514/A on it instead) emulation of XGA for both MCA and ISA buses.

src/config.c

@@ -931,6 +931,7 @@ load_video(void)
 
     voodoo_enabled = !!config_get_int(cat, "voodoo", 0);
     ibm8514_enabled = !!config_get_int(cat, "8514a", 0);
+    xga_enabled = !!config_get_int(cat, "xga", 0);
 }
 
 
@@ -2474,6 +2475,11 @@ save_video(void)
       else
 	config_set_int(cat, "8514a", ibm8514_enabled);
 
+    if (xga_enabled == 0)
+	config_delete_var(cat, "xga");
+      else
+	config_set_int(cat, "xga", xga_enabled);
+
     delete_section_if_empty(cat);
 }
 

src/include/86box/vid_svga.h

@@ -19,6 +19,7 @@
 
 #include <86box/thread.h>
 #include <86box/vid_8514a.h>
+#include <86box/vid_xga.h>
 
 #ifndef VIDEO_SVGA_H
 # define VIDEO_SVGA_H
@@ -49,6 +50,7 @@ typedef union {
 typedef struct svga_t
 {
     ibm8514_t dev8514;
+    xga_t xga;
     mem_mapping_t mapping;
 
     uint8_t fast, chain4, chain2_write, chain2_read,
@@ -176,6 +178,9 @@ extern int vga_on, ibm8514_on;
 extern void ibm8514_poll(ibm8514_t *dev, svga_t *svga);
 extern void ibm8514_recalctimings(svga_t *svga);
 
+extern void xga_poll(xga_t *xga, svga_t *svga);
+extern void xga_recalctimings(svga_t *svga);
+
 extern int	svga_init(const device_t *info, svga_t *svga, void *p, int memsize,
 			  void (*recalctimings_ex)(struct svga_t *svga),
 			  uint8_t (*video_in) (uint16_t addr, void *p),

src/include/86box/vid_xga.h

@@ -0,0 +1,162 @@
+/*
+ * 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.
+ *
+ *		IBM XGA emulation.
+ *
+ *
+ *
+ * Authors:	TheCollector1995.
+ *
+ *		Copyright 2022 TheCollector1995.
+ */
+
+#ifndef VIDEO_XGA_H
+# define VIDEO_XGA_H
+
+#include <86box/rom.h>
+
+typedef struct {
+    int ena;
+    int x, y, xoff, yoff, xsize, ysize;
+    uint32_t addr;
+} xga_hwcursor_t;
+
+typedef struct xga_t
+{
+	mem_mapping_t memio_mapping;
+	mem_mapping_t linear_mapping;
+	mem_mapping_t video_mapping;
+	rom_t bios_rom;
+	xga_hwcursor_t hwcursor, hwcursor_latch;
+    PALETTE extpal;
+
+    uint8_t test, atest[2], testpixel;;
+    uint8_t pos_regs[8];
+    uint8_t disp_addr;
+    uint8_t cfg_reg;
+    uint8_t instance;
+    uint8_t op_mode;
+    uint8_t aperture_cntl;
+    uint8_t ap_idx;
+    uint8_t access_mode;
+    uint8_t regs[0x100];
+    uint8_t regs_idx;
+    uint8_t hwc_hotspot_x;
+    uint8_t hwc_hotspot_y;
+    uint8_t disp_cntl_1, disp_cntl_2;
+    uint8_t clk_sel_1, clk_sel_2;
+    uint8_t hwc_control;
+    uint8_t bus_arb;
+    uint8_t select_pos_isa;
+    uint8_t hwcursor_oddeven;
+    uint8_t cfg_reg_instance;
+    uint8_t rowcount;
+    uint8_t pal_idx, pal_idx_prefetch;
+    uint8_t pal_seq;
+    uint8_t pal_mask;
+    uint8_t pal_r, pal_r_prefetch;
+    uint8_t pal_g, pal_g_prefetch;
+    uint8_t pal_b, pal_b_prefetch;
+    uint8_t sprite_data[1024];
+    uint8_t *vram, *changedvram;
+
+    int16_t hwc_pos_x;
+    int16_t hwc_pos_y;
+
+    uint16_t pos_idx;
+    uint16_t htotal;
+    uint16_t sprite_idx, sprite_idx_prefetch;
+    uint16_t hdisp;
+    uint16_t vtotal;
+    uint16_t vdispend;
+    uint16_t vblankstart;
+    uint16_t vsyncstart;
+    uint16_t linecmp;
+    uint16_t pix_map_width;
+    uint16_t sprite_pal_addr_idx, old_pal_addr_idx;
+    uint16_t sprite_pal_addr_idx_prefetch;
+
+    int v_total, dispend, v_syncstart, split, v_blankstart,
+        h_disp,  h_disp_old, h_total,  h_disp_time, rowoffset,
+        dispon, h_disp_on, vc, sc, linepos, oddeven, firstline, lastline,
+        firstline_draw, lastline_draw, displine, fullchange, interlace,
+        char_width, hwcursor_on;
+    int pal_pos, pal_pos_prefetch;
+    int on;
+    int op_mode_reset;
+    int sprite_pos, sprite_pos_prefetch, cursor_data_on;
+    int pal_test;
+    int from_to_vram;
+
+    uint32_t linear_base, linear_size;
+    uint32_t base_addr_1mb;
+    uint32_t hwc_color0, hwc_color1;
+    uint32_t disp_start_addr;
+    uint32_t ma_latch;
+    uint32_t vram_size;
+    uint32_t vram_mask;
+    uint32_t rom_addr;
+	uint32_t ma, maback;
+	uint32_t extpallook[256];
+	uint32_t read_bank, write_bank;
+	uint32_t px_map_base;
+
+    uint64_t dispontime, dispofftime;
+
+    struct
+    {
+        uint8_t control;
+        uint8_t px_map_idx;
+        uint8_t frgd_mix, bkgd_mix;
+        uint8_t cc_cond;
+        uint8_t octant;
+        uint8_t draw_mode;
+        uint8_t mask_mode;
+        uint8_t short_stroke_vector1;
+        uint8_t short_stroke_vector2;
+        uint8_t short_stroke_vector3;
+        uint8_t short_stroke_vector4;
+
+        int16_t bres_err_term;
+        int16_t bres_k1, bres_k2;
+
+        uint16_t blt_width;
+        uint16_t blt_height;
+        uint16_t mask_map_origin_x_off;
+        uint16_t mask_map_origin_y_off;
+        uint16_t src_map_x, src_map_y;
+        uint16_t dst_map_x, dst_map_y;
+        uint16_t pat_map_x, pat_map_y;
+
+        int ssv_state;
+        int pat_src;
+        int src_map;
+        int dst_map;
+        int bkgd_src;
+        int fore_src;
+        int x, y, sx, sy, dx, dy, px, py;
+        int pattern;
+        int command_len;
+
+        uint32_t short_stroke;
+        uint32_t color_cmp;
+        uint32_t carry_chain;
+        uint32_t plane_mask;
+        uint32_t frgd_color, bkgd_color;
+        uint32_t command;
+        uint32_t dir_cmd;
+
+        uint8_t px_map_format[4];
+        uint16_t px_map_width[4];
+        uint16_t px_map_height[4];
+        uint32_t px_map_base[4];
+    } accel;
+
+    volatile int force_busy;
+} xga_t;
+#endif	/*VIDEO_XGA_H*/

src/qt/qt_settingsdisplay.cpp

@@ -47,6 +47,7 @@ void SettingsDisplay::save() {
     gfxcard = ui->comboBoxVideo->currentData().toInt();
     voodoo_enabled = ui->checkBoxVoodoo->isChecked() ? 1 : 0;
     ibm8514_enabled = ui->checkBox8514->isChecked() ? 1 : 0;
+    xga_enabled = ui->checkBoxXga->isChecked() ? 1 : 0;
 }
 
 void SettingsDisplay::onCurrentMachineChanged(int machineId) {
@@ -119,8 +120,12 @@ void SettingsDisplay::on_comboBoxVideo_currentIndexChanged(int index) {
     bool has_MCA = machine_has_bus(machineId, MACHINE_BUS_MCA) > 0;
     ui->checkBox8514->setEnabled(hasIsa16 || has_MCA);
     if (hasIsa16 || has_MCA) {
-        ui->checkBox8514->setChecked(ibm8514_enabled > 0);
+        ui->checkBox8514->setChecked(ibm8514_enabled);
     }
+
+    ui->checkBoxXga->setEnabled(hasIsa16 || has_MCA);
+    if (hasIsa16 || has_MCA)
+        ui->checkBoxXga->setChecked(xga_enabled);
 }
 
 void SettingsDisplay::on_checkBoxVoodoo_stateChanged(int state) {

src/qt/qt_settingsdisplay.ui

@@ -70,7 +70,14 @@
      </property>
     </widget>
    </item>
-   <item row="3" column="0">
+   <item row="3" column="0" colspan="2">
+    <widget class="QCheckBox" name="checkBoxXga">
+     <property name="text">
+      <string>XGA</string>
+     </property>
+    </widget>
+   </item>
+   <item row="4" column="0">
     <spacer name="verticalSpacer">
      <property name="orientation">
       <enum>Qt::Vertical</enum>

src/video/CMakeLists.txt

@@ -24,7 +24,8 @@ add_library(vid OBJECT agpgart.c video.c vid_table.c vid_cga.c vid_cga_comp.c
     vid_stg_ramdac.c vid_ht216.c vid_oak_oti.c vid_paradise.c vid_rtg310x.c
     vid_f82c425.c vid_ti_cf62011.c vid_tvga.c vid_tgui9440.c vid_tkd8001_ramdac.c
     vid_att20c49x_ramdac.c vid_s3.c vid_s3_virge.c vid_ibm_rgb528_ramdac.c
-    vid_sdac_ramdac.c vid_ogc.c vid_nga.c vid_tvp3026_ramdac.c vid_att2xc498_ramdac.c)
+    vid_sdac_ramdac.c vid_ogc.c vid_nga.c vid_tvp3026_ramdac.c vid_att2xc498_ramdac.c
+    vid_xga.c)
 
 if(MGA)
     target_compile_definitions(vid PRIVATE USE_MGA)

src/video/vid_svga.c

@@ -560,6 +560,8 @@ svga_recalctimings(svga_t *svga)
     } else {
         if (ibm8514_on && ibm8514_enabled)
             ibm8514_recalctimings(svga);
+        if (xga_enabled)
+            xga_recalctimings(svga);
     }
 
     svga->y_add = (overscan_y >> 1) - (svga->crtc[8] & 0x1f);
@@ -660,6 +662,9 @@ svga_poll(void *p)
     if (!vga_on && ibm8514_enabled && ibm8514_on) {
         ibm8514_poll(&svga->dev8514, svga);
         return;
+    } else if (!vga_on && xga_enabled && svga->xga.on) {
+        xga_poll(&svga->xga, svga);
+        return;
     }
 
     if (!svga->linepos) {
@@ -1070,6 +1075,23 @@ svga_write_common(uint32_t addr, uint8_t val, uint8_t linear, void *p)
     cycles -= video_timing_write_b;
 
     if (!linear) {
+	if (xga_enabled) {
+        if (((svga->xga.op_mode & 7) == 4) && (svga->xga.aperture_cntl == 1)) {
+            if (val == 0xa5) { /*Memory size test of XGA*/
+                svga->xga.test = val;
+                return;
+            } else if (val == 0x5a) {
+                svga->xga.test = val;
+                return;
+            } else if (val == 0x12 || val == 0x34) {
+                addr += svga->xga.write_bank;
+                svga->xga.vram[addr & svga->xga.vram_mask] = val;
+                svga->xga.op_mode_reset = 1;
+                return;
+            }
+        } else
+            svga->xga.on = 0;
+	}
 	addr = svga_decode_addr(svga, addr, 1);
 
 	if (addr == 0xffffffff)
@@ -1254,6 +1276,21 @@ svga_read_common(uint32_t addr, uint8_t linear, void *p)
     cycles -= video_timing_read_b;
 
     if (!linear) {
+	if (xga_enabled) {
+        if (((svga->xga.op_mode & 7) == 4) && (svga->xga.aperture_cntl == 1)) {
+            if (svga->xga.test == 0xa5) { /*Memory size test of XGA*/
+                svga->xga.on = 1;
+                return svga->xga.test;
+            } else if (svga->xga.test == 0x5a) {
+                svga->xga.on = 1;
+                return svga->xga.test;
+            } else if (addr == 0xa0000 || addr == 0xa0010) {
+                addr += svga->xga.read_bank;
+                return svga->xga.vram[addr & svga->xga.vram_mask];
+            }
+        } else
+            svga->xga.on = 0;
+	}
 	addr = svga_decode_addr(svga, addr, 0);
 
 	if (addr == 0xffffffff)

src/win/Makefile.mingw

@@ -715,7 +715,8 @@ VIDOBJ		:= agpgart.o video.o \
 		    vid_ibm_rgb528_ramdac.o vid_sdac_ramdac.o \
 			vid_ogc.o \
 			vid_nga.o \
-			vid_tvp3026_ramdac.o
+			vid_tvp3026_ramdac.o \
+			vid_xga.o
 
 VOODOOOBJ	:= vid_voodoo.o vid_voodoo_banshee.o \
 		    vid_voodoo_banshee_blitter.o \