diff --git a/src/include/86box/m_pcjr.h b/src/include/86box/m_pcjr.h
index 3ffcc3b3e..7a137fb03 100644
--- a/src/include/86box/m_pcjr.h
+++ b/src/include/86box/m_pcjr.h
@@ -30,7 +30,7 @@ typedef struct pcjr_s
     uint8_t       array[32];
     int           array_ff;
     int           memctrl;
-    uint8_t       stat;
+    uint8_t       status;
     int           addr_mode;
     uint8_t      *vram;
     uint8_t      *b8000;
diff --git a/src/include/86box/m_tandy.h b/src/include/86box/m_tandy.h
index 392c9b8a5..2d0100c1a 100644
--- a/src/include/86box/m_tandy.h
+++ b/src/include/86box/m_tandy.h
@@ -27,7 +27,7 @@ typedef struct t1kvid_t {
     int     memctrl;
     uint8_t mode;
     uint8_t col;
-    uint8_t stat;
+    uint8_t status;
 
     uint8_t *vram;
     uint8_t *b8000;
diff --git a/src/include/86box/vid_ega.h b/src/include/86box/vid_ega.h
index 6c88d50e6..7cd29aa08 100644
--- a/src/include/86box/vid_ega.h
+++ b/src/include/86box/vid_ega.h
@@ -39,7 +39,7 @@ typedef struct ega_t {
     uint8_t lb;
     uint8_t lc;
     uint8_t ld;
-    uint8_t stat;
+    uint8_t status;
     uint8_t colourcompare;
     uint8_t colournocare;
     uint8_t scrblank;
diff --git a/src/include/86box/vid_hercules.h b/src/include/86box/vid_hercules.h
index c2d2770a9..3d9324124 100644
--- a/src/include/86box/vid_hercules.h
+++ b/src/include/86box/vid_hercules.h
@@ -31,7 +31,7 @@ typedef struct {
 
     uint8_t ctrl;
     uint8_t ctrl2;
-    uint8_t stat;
+    uint8_t status;
 
     uint64_t   dispontime;
     uint64_t   dispofftime;
diff --git a/src/include/86box/vid_mda.h b/src/include/86box/vid_mda.h
index 44123ce52..4cd7e2c54 100644
--- a/src/include/86box/vid_mda.h
+++ b/src/include/86box/vid_mda.h
@@ -1,18 +1,78 @@
-/* Copyright holders: Sarah Walker
-   see COPYING for more details
-*/
+/*
+ * 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,
+    MDA_MODE_VIDEO_ENABLE = 1 << 3,
+    MDA_MODE_BLINK = 1 << 5,
+} mda_mode_flags;
+
 typedef struct mda_t {
     mem_mapping_t mapping;
 
-    uint8_t crtc[32];
+    uint8_t crtc[MDA_CRTC_NUM_REGISTERS];
     int     crtcreg;
 
-    uint8_t ctrl;
-    uint8_t stat;
+    uint8_t mode;
+    uint8_t status;
 
     uint64_t   dispontime;
     uint64_t   dispofftime;
diff --git a/src/machine/m_amstrad.c b/src/machine/m_amstrad.c
index 0c39c2176..584b7b3ac 100644
--- a/src/machine/m_amstrad.c
+++ b/src/machine/m_amstrad.c
@@ -105,7 +105,7 @@ typedef struct amsvid_t {
     int        cga_enabled; /* 1640 */
     uint8_t    cgacol;
     uint8_t    cgamode;
-    uint8_t    stat;
+    uint8_t    status;
     uint8_t    plane_write; /* 1512/200 */
     uint8_t    plane_read;  /* 1512/200 */
     uint8_t    border;      /* 1512/200 */
@@ -290,7 +290,7 @@ vid_in_1512(uint16_t addr, void *priv)
             break;
 
         case 0x03da:
-            ret = vid->stat;
+            ret = vid->status;
             break;
 
         default:
@@ -357,7 +357,7 @@ vid_poll_1512(void *priv)
 
     if (!vid->linepos) {
         timer_advance_u64(&vid->timer, vid->dispofftime);
-        vid->stat |= 1;
+        vid->status |= 1;
         vid->linepos = 1;
         scanline_old        = vid->scanline;
         if (vid->dispon) {
@@ -496,7 +496,7 @@ vid_poll_1512(void *priv)
 
         vid->scanline = scanline_old;
         if (vid->vsynctime)
-            vid->stat |= 8;
+            vid->status |= 8;
         vid->displine++;
         if (vid->displine >= 360)
             vid->displine = 0;
@@ -505,12 +505,12 @@ vid_poll_1512(void *priv)
         if ((vid->lastline - vid->firstline) == 199)
             vid->dispon = 0; /*Amstrad PC1512 always displays 200 lines, regardless of CRTC settings*/
         if (vid->dispon)
-            vid->stat &= ~1;
+            vid->status &= ~1;
         vid->linepos = 0;
         if (vid->vsynctime) {
             vid->vsynctime--;
             if (!vid->vsynctime)
-                vid->stat &= ~8;
+                vid->status &= ~8;
         }
         if (vid->scanline == (vid->crtc[11] & 31)) {
             vid->cursorvisible  = 0;
@@ -1044,7 +1044,7 @@ vid_in_200(uint16_t addr, void *priv)
 
     switch (addr) {
         case 0x03b8:
-            return (mda->ctrl);
+            return (mda->mode);
 
         case 0x03d8:
             return (cga->cgamode);
@@ -1106,9 +1106,9 @@ vid_out_200(uint16_t addr, uint8_t val, void *priv)
             }
             return;
         case 0x3b8:
-            old       = mda->ctrl;
-            mda->ctrl = val;
-            if ((mda->ctrl ^ old) & 3)
+            old       = mda->mode;
+            mda->mode = val;
+            if ((mda->mode ^ old) & 3)
                 mda_recalctimings(mda);
             vid->crtc_index &= 0x1F;
             vid->crtc_index |= 0x80;
@@ -1269,7 +1269,7 @@ static void
 lcdm_poll(amsvid_t *vid)
 {
     mda_t   *mda = &vid->mda;
-    uint16_t cursoraddr  = (mda->crtc[15] | (mda->crtc[14] << 8)) & 0x3fff;
+    uint16_t cursoraddr  = (mda->crtc[MDA_CRTC_CURSOR_ADDR_LOW] | (mda->crtc[MDA_CRTC_CURSOR_ADDR_HIGH] << 8)) & 0x3fff;
     int      drawcursor;
     int      x;
     int      oldvc;
@@ -1280,42 +1280,42 @@ lcdm_poll(amsvid_t *vid)
 
     if (!mda->linepos) {
         timer_advance_u64(&vid->timer, mda->dispofftime);
-        mda->stat |= 1;
+        mda->status |= 1;
         mda->linepos = 1;
         scanline_old        = mda->scanline;
-        if ((mda->crtc[8] & 3) == 3)
+        if ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3)
             mda->scanline = (mda->scanline << 1) & 7;
         if (mda->dispon) {
             if (mda->displine < mda->firstline)
                 mda->firstline = mda->displine;
             mda->lastline = mda->displine;
-            for (x = 0; x < mda->crtc[1]; x++) {
+            for (x = 0; x < mda->crtc[MDA_CRTC_HDISP]; x++) {
                 chr        = mda->vram[(mda->memaddr<< 1) & 0xfff];
                 attr       = mda->vram[((mda->memaddr<< 1) + 1) & 0xfff];
                 drawcursor = ((mda->memaddr== cursoraddr) && mda->cursorvisible && mda->cursoron);
-                blink      = ((mda->blink & 16) && (mda->ctrl & 0x20) && (attr & 0x80) && !drawcursor);
+                blink      = ((mda->blink & 16) && (mda->mode & MDA_MODE_BLINK) && (attr & 0x80) && !drawcursor);
 
-                lcd_draw_char_80(vid, &(buffer32->line[mda->displine])[x * 8], chr, attr, drawcursor, blink, mda->scanline, 0, mda->ctrl);
+                lcd_draw_char_80(vid, &(buffer32->line[mda->displine])[x * 8], chr, attr, drawcursor, blink, mda->scanline, 0, mda->mode);
                 mda->memaddr++;
             }
         }
         mda->scanline = scanline_old;
-        if (mda->vc == mda->crtc[7] && !mda->scanline)
-            mda->stat |= 8;
+        if (mda->vc == mda->crtc[MDA_CRTC_VSYNC] && !mda->scanline)
+            mda->status |= 8;
         mda->displine++;
         if (mda->displine >= 500)
             mda->displine = 0;
     } else {
         timer_advance_u64(&vid->timer, mda->dispontime);
         if (mda->dispon)
-            mda->stat &= ~1;
+            mda->status &= ~1;
         mda->linepos = 0;
         if (mda->vsynctime) {
             mda->vsynctime--;
             if (!mda->vsynctime)
-                mda->stat &= ~8;
+                mda->status &= ~8;
         }
-        if (mda->scanline == (mda->crtc[11] & 31) || ((mda->crtc[8] & 3) == 3 && mda->scanline == ((mda->crtc[11] & 31) >> 1))) {
+        if (mda->scanline == (mda->crtc[MDA_CRTC_CURSOR_END] & 31) || ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3 && mda->scanline == ((mda->crtc[MDA_CRTC_CURSOR_END] & 31) >> 1))) {
             mda->cursorvisible  = 0;
         }
         if (mda->vadj) {
@@ -1325,35 +1325,35 @@ lcdm_poll(amsvid_t *vid)
             mda->vadj--;
             if (!mda->vadj) {
                 mda->dispon = 1;
-                mda->memaddr= mda->memaddr_backup = (mda->crtc[13] | (mda->crtc[12] << 8)) & 0x3fff;
+                mda->memaddr= mda->memaddr_backup = (mda->crtc[MDA_CRTC_START_ADDR_LOW] | (mda->crtc[MDA_CRTC_START_ADDR_HIGH] << 8)) & 0x3fff;
                 mda->scanline               = 0;
             }
-        } else if (mda->scanline == mda->crtc[9] || ((mda->crtc[8] & 3) == 3 && mda->scanline == (mda->crtc[9] >> 1))) {
+        } else if (mda->scanline == mda->crtc[MDA_CRTC_MAX_SCANLINE_ADDR] || ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3 && mda->scanline == (mda->crtc[MDA_CRTC_MAX_SCANLINE_ADDR] >> 1))) {
             mda->memaddr_backup = mda->memaddr;
             mda->scanline     = 0;
             oldvc       = mda->vc;
             mda->vc++;
             mda->vc &= 127;
-            if (mda->vc == mda->crtc[6])
+            if (mda->vc == mda->crtc[MDA_CRTC_VDISP])
                 mda->dispon = 0;
-            if (oldvc == mda->crtc[4]) {
+            if (oldvc == mda->crtc[MDA_CRTC_VTOTAL]) {
                 mda->vc   = 0;
-                mda->vadj = mda->crtc[5];
+                mda->vadj = mda->crtc[MDA_CRTC_VTOTAL_ADJUST];
                 if (!mda->vadj)
                     mda->dispon = 1;
                 if (!mda->vadj)
-                    mda->memaddr= mda->memaddr_backup = (mda->crtc[13] | (mda->crtc[12] << 8)) & 0x3fff;
-                if ((mda->crtc[10] & 0x60) == 0x20)
+                    mda->memaddr= mda->memaddr_backup = (mda->crtc[MDA_CRTC_START_ADDR_LOW] | (mda->crtc[MDA_CRTC_START_ADDR_HIGH] << 8)) & 0x3fff;
+                if ((mda->crtc[MDA_CRTC_CURSOR_START] & 0x60) == 0x20)
                     mda->cursoron = 0;
                 else
                     mda->cursoron = mda->blink & 16;
             }
-            if (mda->vc == mda->crtc[7]) {
+            if (mda->vc == mda->crtc[MDA_CRTC_VSYNC]) {
                 mda->dispon    = 0;
                 mda->displine  = 0;
                 mda->vsynctime = 16;
-                if (mda->crtc[7]) {
-                    x = mda->crtc[1] * 8;
+                if (mda->crtc[MDA_CRTC_VSYNC]) {
+                    x = mda->crtc[MDA_CRTC_HDISP] * 8;
                     mda->lastline++;
                     if ((x != xsize) || ((mda->lastline - mda->firstline) != ysize) || video_force_resize_get()) {
                         xsize = x;
@@ -1369,8 +1369,8 @@ lcdm_poll(amsvid_t *vid)
                     }
                     video_blit_memtoscreen(0, mda->firstline, xsize, ysize);
                     frames++;
-                    video_res_x = mda->crtc[1];
-                    video_res_y = mda->crtc[6];
+                    video_res_x = mda->crtc[MDA_CRTC_HDISP];
+                    video_res_y = mda->crtc[MDA_CRTC_VDISP];
                     video_bpp   = 0;
                 }
                 mda->firstline = 1000;
@@ -1382,7 +1382,7 @@ lcdm_poll(amsvid_t *vid)
             mda->scanline &= 31;
             mda->memaddr= mda->memaddr_backup;
         }
-        if (mda->scanline == (mda->crtc[10] & 31) || ((mda->crtc[8] & 3) == 3 && mda->scanline == ((mda->crtc[10] & 31) >> 1)))
+        if (mda->scanline == (mda->crtc[MDA_CRTC_CURSOR_START] & 31) || ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3 && mda->scanline == ((mda->crtc[MDA_CRTC_CURSOR_START] & 31) >> 1)))
             mda->cursorvisible = 1;
     }
 }
diff --git a/src/video/vid_8514a.c b/src/video/vid_8514a.c
index dcac57fe1..97202340d 100644
--- a/src/video/vid_8514a.c
+++ b/src/video/vid_8514a.c
@@ -459,7 +459,7 @@ ibm8514_accel_out_fifo(svga_t *svga, uint16_t port, uint32_t val, int len)
             break;
 
         case 0x42e8:
-            ibm8514_log("VBLANK stat=%02x, val=%02x.\n", dev->subsys_stat, val);
+            ibm8514_log("VBLANK status=%02x, val=%02x.\n", dev->subsys_stat, val);
             if (len == 2) {
                 dev->subsys_cntl = val;
                 dev->subsys_stat &= ~val;
diff --git a/src/video/vid_ati_mach8.c b/src/video/vid_ati_mach8.c
index 32a1c2b9e..9dd736cd7 100644
--- a/src/video/vid_ati_mach8.c
+++ b/src/video/vid_ati_mach8.c
@@ -3297,7 +3297,7 @@ mach_accel_out_fifo(mach_t *mach, svga_t *svga, ibm8514_t *dev, uint16_t port, u
 
         case 0x42e8:
         case 0x42e9:
-            mach_log("VBLANK stat=%02x, val=%02x.\n", dev->subsys_stat, val);
+            mach_log("VBLANK status=%02x, val=%02x.\n", dev->subsys_stat, val);
             if (len == 2)
                 dev->subsys_cntl = val;
             else {
diff --git a/src/video/vid_cga_toshiba_t3100e.c b/src/video/vid_cga_toshiba_t3100e.c
index 9f7c2f526..e3eb673c8 100644
--- a/src/video/vid_cga_toshiba_t3100e.c
+++ b/src/video/vid_cga_toshiba_t3100e.c
@@ -169,8 +169,8 @@ t3100e_out(uint16_t addr, uint8_t val, void *priv)
             t3100e_recalctimings(t3100e);
             return;
 
-        case 0x3D8: /* CGA control register */
-        case 0x3D9: /* CGA colour register */
+        case CGA_REGISTER_MODE_CONTROL: /* CGA control register */
+        case CGA_REGISTER_COLOR_SELECT: /* CGA colour register */
             cga_out(addr, val, &t3100e->cga);
             return;
 
diff --git a/src/video/vid_ega.c b/src/video/vid_ega.c
index 3b4e8cce0..d937b2458 100644
--- a/src/video/vid_ega.c
+++ b/src/video/vid_ega.c
@@ -505,7 +505,7 @@ ega_in(uint16_t addr, void *priv)
         case 0x3da:
             ega->attrff = 0;
             if (type == EGA_TYPE_COMPAQ) {
-                ret = ega->stat & 0xcf;
+                ret = ega->status & 0xcf;
                 switch ((ega->attrregs[0x12] >> 4) & 0x03) {
                     case 0x00:
                         /* 00 = Pri. Red (5), Pri. Blue (4) */
@@ -526,8 +526,8 @@ ega_in(uint16_t addr, void *priv)
                         break;
                 }
             } else {
-                ega->stat ^= 0x30; /* Fools IBM EGA video BIOS self-test. */
-                ret = ega->stat;
+                ega->status ^= 0x30; /* Fools IBM EGA video BIOS self-test. */
+                ret = ega->status;
             }
             break;
         case 0x7c6:
@@ -837,7 +837,7 @@ ega_poll(void *priv)
 
     if (!ega->linepos) {
         timer_advance_u64(&ega->timer, ega->dispofftime);
-        ega->stat |= 1;
+        ega->status |= 1;
         ega->linepos = 1;
 
         if (ega->dispon) {
@@ -877,8 +877,8 @@ ega_poll(void *priv)
         ega->displine++;
         if (ega->interlace)
             ega->displine++;
-        if ((ega->stat & 8) && ((ega->displine & 15) == (ega->crtc[0x11] & 15)) && ega->vslines)
-            ega->stat &= ~8;
+        if ((ega->status & 8) && ((ega->displine & 15) == (ega->crtc[0x11] & 15)) && ega->vslines)
+            ega->status &= ~8;
         ega->vslines++;
         if (ega->chipset) {
             if (ega->hdisp >= 800) {
@@ -896,7 +896,7 @@ ega_poll(void *priv)
         timer_advance_u64(&ega->timer, ega->dispontime);
 
         if (ega->dispon)
-            ega->stat &= ~1;
+            ega->status &= ~1;
         ega->hdisp_on = 0;
 
         ega->linepos = 0;
@@ -968,7 +968,7 @@ ega_poll(void *priv)
         }
         if (ega->vc == ega->vsyncstart) {
             ega->dispon = 0;
-            ega->stat |= 8;
+            ega->status |= 8;
 #if 0
             picint(1 << 2);
 #endif
diff --git a/src/video/vid_hercules.c b/src/video/vid_hercules.c
index 4b8d796a3..5e0ac1bc9 100644
--- a/src/video/vid_hercules.c
+++ b/src/video/vid_hercules.c
@@ -178,8 +178,8 @@ hercules_in(uint16_t addr, void *priv)
         case 0x03ba:
             ret = 0x70; /* Hercules ident */
             ret |= (dev->lp_ff ? 2 : 0);
-            ret |= (dev->stat & 0x01);
-            if (dev->stat & 0x08)
+            ret |= (dev->status & 0x01);
+            if (dev->status & 0x08)
                 ret |= 0x80;
             if ((ret & 0x81) == 0x80)
                 ret |= 0x08;
@@ -300,7 +300,7 @@ hercules_poll(void *priv)
 
     if (!dev->linepos) {
         timer_advance_u64(&dev->timer, dev->dispofftime);
-        dev->stat |= 1;
+        dev->status |= 1;
         dev->linepos = 1;
         scanline_old        = dev->scanline;
 
@@ -380,7 +380,7 @@ hercules_poll(void *priv)
         dev->scanline = scanline_old;
 
         if (dev->vc == dev->crtc[7] && !dev->scanline)
-            dev->stat |= 8;
+            dev->status |= 8;
         dev->displine++;
         if (dev->displine >= 500)
             dev->displine = 0;
@@ -388,13 +388,13 @@ hercules_poll(void *priv)
         timer_advance_u64(&dev->timer, dev->dispontime);
 
         if (dev->dispon)
-            dev->stat &= ~1;
+            dev->status &= ~1;
 
         dev->linepos = 0;
         if (dev->vsynctime) {
             dev->vsynctime--;
             if (!dev->vsynctime)
-                dev->stat &= ~8;
+                dev->status &= ~8;
         }
 
         if (dev->scanline == (dev->crtc[11] & 31) || ((dev->crtc[8] & 3) == 3 && dev->scanline == ((dev->crtc[11] & 31) >> 1))) {
diff --git a/src/video/vid_hercules_incolor.c b/src/video/vid_hercules_incolor.c
index 6e202d338..c4751e8fa 100644
--- a/src/video/vid_hercules_incolor.c
+++ b/src/video/vid_hercules_incolor.c
@@ -157,7 +157,7 @@ typedef struct {
     uint8_t crtc[32];
     int     crtcreg;
 
-    uint8_t ctrl, ctrl2, stat;
+    uint8_t ctrl, ctrl2, status;
 
     uint64_t   dispontime, dispofftime;
     pc_timer_t timer;
@@ -285,7 +285,7 @@ incolor_in(uint16_t port, void *priv)
 
         case 0x3ba:
             /* 0x50: InColor card identity */
-            ret = (dev->stat & 0xf) | ((dev->stat & 8) << 4) | 0x50;
+            ret = (dev->status & 0xf) | ((dev->status & 8) << 4) | 0x50;
             break;
 
         default:
@@ -863,7 +863,7 @@ incolor_poll(void *priv)
 
     if (!dev->linepos) {
         timer_advance_u64(&dev->timer, dev->dispofftime);
-        dev->stat |= 1;
+        dev->status |= 1;
         dev->linepos = 1;
         scanline_old        = dev->scanline;
         if ((dev->crtc[8] & 3) == 3)
@@ -882,19 +882,19 @@ incolor_poll(void *priv)
         }
         dev->scanline = scanline_old;
         if (dev->vc == dev->crtc[7] && !dev->scanline)
-            dev->stat |= 8;
+            dev->status |= 8;
         dev->displine++;
         if (dev->displine >= 500)
             dev->displine = 0;
     } else {
         timer_advance_u64(&dev->timer, dev->dispontime);
         if (dev->dispon)
-            dev->stat &= ~1;
+            dev->status &= ~1;
         dev->linepos = 0;
         if (dev->vsynctime) {
             dev->vsynctime--;
             if (!dev->vsynctime)
-                dev->stat &= ~8;
+                dev->status &= ~8;
         }
 
         if (dev->scanline == (dev->crtc[11] & 31) || ((dev->crtc[8] & 3) == 3 && dev->scanline == ((dev->crtc[11] & 31) >> 1))) {
diff --git a/src/video/vid_hercules_plus.c b/src/video/vid_hercules_plus.c
index 4a2790dc0..0c6125d0b 100644
--- a/src/video/vid_hercules_plus.c
+++ b/src/video/vid_hercules_plus.c
@@ -67,7 +67,7 @@ typedef struct {
     uint8_t crtc[32];
     int     crtcreg;
 
-    uint8_t ctrl, ctrl2, stat;
+    uint8_t ctrl, ctrl2, status;
 
     uint64_t   dispontime, dispofftime;
     pc_timer_t timer;
@@ -194,7 +194,7 @@ herculesplus_in(uint16_t port, void *priv)
 
         case 0x3ba:
             /* 0x10: Hercules Plus card identity */
-            ret = (dev->stat & 0xf) | ((dev->stat & 8) << 4) | 0x10;
+            ret = (dev->status & 0xf) | ((dev->status & 8) << 4) | 0x10;
             break;
 
         default:
@@ -494,7 +494,7 @@ herculesplus_poll(void *priv)
     VIDEO_MONITOR_PROLOGUE();
     if (!dev->linepos) {
         timer_advance_u64(&dev->timer, dev->dispofftime);
-        dev->stat |= 1;
+        dev->status |= 1;
         dev->linepos = 1;
         scanline_old        = dev->scanline;
         if ((dev->crtc[8] & 3) == 3)
@@ -519,19 +519,19 @@ herculesplus_poll(void *priv)
         }
         dev->scanline = scanline_old;
         if (dev->vc == dev->crtc[7] && !dev->scanline)
-            dev->stat |= 8;
+            dev->status |= 8;
         dev->displine++;
         if (dev->displine >= 500)
             dev->displine = 0;
     } else {
         timer_advance_u64(&dev->timer, dev->dispontime);
         if (dev->dispon)
-            dev->stat &= ~1;
+            dev->status &= ~1;
         dev->linepos = 0;
         if (dev->vsynctime) {
             dev->vsynctime--;
             if (!dev->vsynctime)
-                dev->stat &= ~8;
+                dev->status &= ~8;
         }
 
         if (dev->scanline == (dev->crtc[11] & 31) || ((dev->crtc[8] & 3) == 3 && dev->scanline == ((dev->crtc[11] & 31) >> 1))) {
diff --git a/src/video/vid_mda.c b/src/video/vid_mda.c
index 4928441e6..c8a739fbe 100644
--- a/src/video/vid_mda.c
+++ b/src/video/vid_mda.c
@@ -12,9 +12,11 @@
  *
  * Authors: Sarah Walker, <https://pcem-emulator.co.uk/>
  *          Miran Grca, <mgrca8@gmail.com>
+ *          Connor Hyde, <mario64crashed@gmail.com>
  *
  *          Copyright 2008-2019 Sarah Walker.
  *          Copyright 2016-2025 Miran Grca.
+ *          Copyright 2025 starfrost / Connor Hyde
  */
 #include <stdio.h>
 #include <stdint.h>
@@ -44,32 +46,35 @@ mda_out(uint16_t addr, uint8_t val, void *priv)
 {
     mda_t *mda = (mda_t *) priv;
 
-    switch (addr) {
-        case 0x3b0:
-        case 0x3b2:
-        case 0x3b4:
-        case 0x3b6:
-            mda->crtcreg = val & 31;
-            return;
-        case 0x3b1:
-        case 0x3b3:
-        case 0x3b5:
-        case 0x3b7:
-            mda->crtc[mda->crtcreg] = val;
-            if (mda->crtc[10] == 6 && mda->crtc[11] == 7) /*Fix for Generic Turbo XT BIOS, which sets up cursor registers wrong*/
-            {
-                mda->crtc[10] = 0xb;
-                mda->crtc[11] = 0xc;
-            }
-            mda_recalctimings(mda);
-            return;
-        case 0x3b8:
-            mda->ctrl = val;
-            return;
+    if (addr < MDA_REGISTER_START 
+    || addr > MDA_REGISTER_CRT_STATUS)  // Maintain old behaviour for printer registers, just in case
+        return;
 
+    switch (addr)
+    {
+        case MDA_REGISTER_MODE_CONTROL:
+            mda->mode = val;
+            return;
         default:
             break;
     }
+
+    // addr & 1 == 1 = MDA_REGISTER_CRTC_DATA
+    // otherwise       MDA_REGISTER_CRTC_INDEX
+    if (addr & 1)
+    {
+        mda->crtc[mda->crtcreg] = val;
+        if (mda->crtc[MDA_CRTC_CURSOR_START] == 6 
+            && mda->crtc[MDA_CRTC_CURSOR_END] == 7) /*Fix for Generic Turbo XT BIOS, which sets up cursor registers wrong*/
+        {
+            mda->crtc[MDA_CRTC_CURSOR_START] = 0xb;
+            mda->crtc[MDA_CRTC_CURSOR_END] = 0xc;
+        }
+        mda_recalctimings(mda);
+    }
+    else
+        mda->crtcreg = val & 31;
+
 }
 
 uint8_t
@@ -77,24 +82,26 @@ mda_in(uint16_t addr, void *priv)
 {
     const mda_t *mda = (mda_t *) priv;
 
-    switch (addr) {
-        case 0x3b0:
-        case 0x3b2:
-        case 0x3b4:
-        case 0x3b6:
-            return mda->crtcreg;
-        case 0x3b1:
-        case 0x3b3:
-        case 0x3b5:
-        case 0x3b7:
-            return mda->crtc[mda->crtcreg];
-        case 0x3ba:
-            return mda->stat | 0xF0;
+    switch (addr)
+    {
+        case MDA_REGISTER_CRT_STATUS:
+            return mda->status | 0xF0;
 
         default:
+            if (addr < MDA_REGISTER_START 
+            || addr > MDA_REGISTER_CRT_STATUS)  // Maintain old behaviour for printer registers, just in case
+                return 0xFF;
+
+            // MDA_REGISTER_CRTC_DATA
+            if (addr & 1)
+                return mda->crtc[mda->crtcreg];
+            else 
+                return mda->crtcreg;
+
             break;
     }
-    return 0xff;
+
+    return 0xFF;
 }
 
 void
@@ -118,8 +125,8 @@ mda_recalctimings(mda_t *mda)
     double _dispontime;
     double _dispofftime;
     double disptime;
-    disptime     = mda->crtc[0] + 1;
-    _dispontime  = mda->crtc[1];
+    disptime     = mda->crtc[MDA_CRTC_HTOTAL] + 1;
+    _dispontime  = mda->crtc[MDA_CRTC_HDISP];
     _dispofftime = disptime - _dispontime;
     _dispontime *= MDACONST;
     _dispofftime *= MDACONST;
@@ -131,7 +138,7 @@ void
 mda_poll(void *priv)
 {
     mda_t   *mda = (mda_t *) priv;
-    uint16_t cursoraddr  = (mda->crtc[15] | (mda->crtc[14] << 8)) & 0x3fff;
+    uint16_t cursoraddr  = (mda->crtc[MDA_CRTC_CURSOR_ADDR_LOW] | (mda->crtc[MDA_CRTC_CURSOR_ADDR_HIGH] << 8)) & 0x3fff;
     int      drawcursor;
     int      x;
     int      c;
@@ -144,10 +151,10 @@ mda_poll(void *priv)
     VIDEO_MONITOR_PROLOGUE()
     if (!mda->linepos) {
         timer_advance_u64(&mda->timer, mda->dispofftime);
-        mda->stat |= 1;
+        mda->status |= 1;
         mda->linepos = 1;
         scanline_old        = mda->scanline;
-        if ((mda->crtc[8] & 3) == 3)
+        if ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3)
             mda->scanline = (mda->scanline << 1) & 7;
         if (mda->dispon) {
             if (mda->displine < mda->firstline) {
@@ -155,11 +162,11 @@ mda_poll(void *priv)
                 video_wait_for_buffer();
             }
             mda->lastline = mda->displine;
-            for (x = 0; x < mda->crtc[1]; x++) {
+            for (x = 0; x < mda->crtc[MDA_CRTC_HDISP]; x++) {
                 chr        = mda->vram[(mda->memaddr << 1) & 0xfff];
                 attr       = mda->vram[((mda->memaddr << 1) + 1) & 0xfff];
                 drawcursor = ((mda->memaddr == cursoraddr) && mda->cursorvisible && mda->cursoron);
-                blink      = ((mda->blink & 16) && (mda->ctrl & 0x20) && (attr & 0x80) && !drawcursor);
+                blink      = ((mda->blink & 16) && (mda->mode & MDA_MODE_BLINK) && (attr & 0x80) && !drawcursor);
                 if (mda->scanline == 12 && ((attr & 7) == 1)) {
                     for (c = 0; c < 9; c++)
                         buffer32->line[mda->displine][(x * 9) + c] = mdacols[attr][blink][1];
@@ -178,11 +185,11 @@ mda_poll(void *priv)
                 }
             }
 
-            video_process_8(mda->crtc[1] * 9, mda->displine);
+            video_process_8(mda->crtc[MDA_CRTC_HDISP] * 9, mda->displine);
         }
         mda->scanline = scanline_old;
-        if (mda->vc == mda->crtc[7] && !mda->scanline) {
-            mda->stat |= 8;
+        if (mda->vc == mda->crtc[MDA_CRTC_VSYNC] && !mda->scanline) {
+            mda->status |= 8;
         }
         mda->displine++;
         if (mda->displine >= 500)
@@ -190,15 +197,17 @@ mda_poll(void *priv)
     } else {
         timer_advance_u64(&mda->timer, mda->dispontime);
         if (mda->dispon)
-            mda->stat &= ~1;
+            mda->status &= ~1;
         mda->linepos = 0;
         if (mda->vsynctime) {
             mda->vsynctime--;
             if (!mda->vsynctime) {
-                mda->stat &= ~8;
+                mda->status &= ~8;
             }
         }
-        if (mda->scanline == (mda->crtc[11] & 31) || ((mda->crtc[8] & 3) == 3 && mda->scanline == ((mda->crtc[11] & 31) >> 1))) {
+        if (mda->scanline == (mda->crtc[MDA_CRTC_CURSOR_END] & 31) 
+        || ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3
+        && mda->scanline == ((mda->crtc[MDA_CRTC_CURSOR_END] & 31) >> 1))) {
             mda->cursorvisible  = 0;
         }
         if (mda->vadj) {
@@ -208,35 +217,37 @@ mda_poll(void *priv)
             mda->vadj--;
             if (!mda->vadj) {
                 mda->dispon = 1;
-                mda->memaddr = mda->memaddr_backup = (mda->crtc[13] | (mda->crtc[12] << 8)) & 0x3fff;
+                mda->memaddr = mda->memaddr_backup = (mda->crtc[MDA_CRTC_START_ADDR_LOW] | (mda->crtc[MDA_CRTC_START_ADDR_HIGH] << 8)) & 0x3fff;
                 mda->scanline               = 0;
             }
-        } else if (mda->scanline == mda->crtc[9] || ((mda->crtc[8] & 3) == 3 && mda->scanline == (mda->crtc[9] >> 1))) {
+        } else if (mda->scanline == mda->crtc[MDA_CRTC_MAX_SCANLINE_ADDR]
+            || ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3 
+            && mda->scanline == (mda->crtc[MDA_CRTC_MAX_SCANLINE_ADDR] >> 1))) {
             mda->memaddr_backup = mda->memaddr;
             mda->scanline     = 0;
             oldvc       = mda->vc;
             mda->vc++;
             mda->vc &= 127;
-            if (mda->vc == mda->crtc[6])
+            if (mda->vc == mda->crtc[MDA_CRTC_VDISP])
                 mda->dispon = 0;
-            if (oldvc == mda->crtc[4]) {
+            if (oldvc == mda->crtc[MDA_CRTC_VTOTAL]) {
                 mda->vc   = 0;
-                mda->vadj = mda->crtc[5];
+                mda->vadj = mda->crtc[MDA_CRTC_VTOTAL_ADJUST];
                 if (!mda->vadj)
                     mda->dispon = 1;
                 if (!mda->vadj)
-                    mda->memaddr = mda->memaddr_backup = (mda->crtc[13] | (mda->crtc[12] << 8)) & 0x3fff;
-                if ((mda->crtc[10] & 0x60) == 0x20)
+                    mda->memaddr = mda->memaddr_backup = (mda->crtc[MDA_CRTC_START_ADDR_LOW] | (mda->crtc[MDA_CRTC_START_ADDR_HIGH] << 8)) & 0x3fff;
+                if ((mda->crtc[MDA_CRTC_CURSOR_START] & 0x60) == 0x20)
                     mda->cursoron = 0;
                 else
                     mda->cursoron = mda->blink & 16;
             }
-            if (mda->vc == mda->crtc[7]) {
+            if (mda->vc == mda->crtc[MDA_CRTC_VSYNC]) {
                 mda->dispon    = 0;
                 mda->displine  = 0;
                 mda->vsynctime = 16;
-                if (mda->crtc[7]) {
-                    x = mda->crtc[1] * 9;
+                if (mda->crtc[MDA_CRTC_VSYNC]) {
+                    x = mda->crtc[MDA_CRTC_HDISP] * 9;
                     mda->lastline++;
                     if ((x != xsize) || ((mda->lastline - mda->firstline) != ysize) || video_force_resize_get()) {
                         xsize = x;
@@ -252,8 +263,8 @@ mda_poll(void *priv)
                     }
                     video_blit_memtoscreen(0, mda->firstline, xsize, ysize);
                     frames++;
-                    video_res_x = mda->crtc[1];
-                    video_res_y = mda->crtc[6];
+                    video_res_x = mda->crtc[MDA_CRTC_HDISP];
+                    video_res_y = mda->crtc[MDA_CRTC_VDISP];
                     video_bpp   = 0;
                 }
                 mda->firstline = 1000;
@@ -265,7 +276,9 @@ mda_poll(void *priv)
             mda->scanline &= 31;
             mda->memaddr = mda->memaddr_backup;
         }
-        if (mda->scanline == (mda->crtc[10] & 31) || ((mda->crtc[8] & 3) == 3 && mda->scanline == ((mda->crtc[10] & 31) >> 1))) {
+        if (mda->scanline == (mda->crtc[MDA_CRTC_CURSOR_START] & 31) 
+        || ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3 
+        && mda->scanline == ((mda->crtc[MDA_CRTC_CURSOR_START] & 31) >> 1))) {
             mda->cursorvisible = 1;
         }
     }
diff --git a/src/video/vid_pcjr.c b/src/video/vid_pcjr.c
index c02275f09..17a43fb40 100644
--- a/src/video/vid_pcjr.c
+++ b/src/video/vid_pcjr.c
@@ -183,8 +183,8 @@ vid_in(uint16_t addr, void *priv)
 
         case 0x3da:
             pcjr->array_ff = 0;
-            pcjr->stat ^= 0x10;
-            ret = pcjr->stat;
+            pcjr->status ^= 0x10;
+            ret = pcjr->status;
             break;
 
         default:
@@ -316,7 +316,7 @@ vid_poll(void *priv)
 
     if (!pcjr->linepos) {
         timer_advance_u64(&pcjr->timer, pcjr->dispofftime);
-        pcjr->stat &= ~1;
+        pcjr->status &= ~1;
         pcjr->linepos = 1;
         scanline_old         = pcjr->scanline;
         if ((pcjr->crtc[8] & 3) == 3)
@@ -557,7 +557,7 @@ vid_poll(void *priv)
         }
         pcjr->scanline = scanline_old;
         if (pcjr->vc == pcjr->crtc[7] && !pcjr->scanline) {
-            pcjr->stat |= 8;
+            pcjr->status |= 8;
         }
         pcjr->displine++;
         if (pcjr->displine >= 360)
@@ -565,12 +565,12 @@ vid_poll(void *priv)
     } else {
         timer_advance_u64(&pcjr->timer, pcjr->dispontime);
         if (pcjr->dispon)
-            pcjr->stat |= 1;
+            pcjr->status |= 1;
         pcjr->linepos = 0;
         if (pcjr->vsynctime) {
             pcjr->vsynctime--;
             if (!pcjr->vsynctime) {
-                pcjr->stat &= ~8;
+                pcjr->status &= ~8;
             }
         }
         if (pcjr->scanline == (pcjr->crtc[11] & 31) || ((pcjr->crtc[8] & 3) == 3 && pcjr->scanline == ((pcjr->crtc[11] & 31) >> 1))) {
diff --git a/src/video/vid_tandy.c b/src/video/vid_tandy.c
index 78e7d55c3..312527a35 100644
--- a/src/video/vid_tandy.c
+++ b/src/video/vid_tandy.c
@@ -268,7 +268,7 @@ tandy_vid_in(uint16_t addr, void *priv)
             break;
 
         case 0x03da:
-            ret = vid->stat;
+            ret = vid->status;
             break;
 
         case 0x3db:
@@ -353,7 +353,7 @@ vid_poll(void *priv)
 
     if (!vid->linepos) {
         timer_advance_u64(&vid->timer, vid->dispofftime);
-        vid->stat |= 1;
+        vid->status |= 1;
         vid->linepos = 1;
         scanline_old        = vid->scanline;
         if ((vid->crtc[8] & 3) == 3)
@@ -574,19 +574,19 @@ vid_poll(void *priv)
         }
         vid->scanline = scanline_old;
         if (vid->vc == vid->crtc[7] && !vid->scanline)
-            vid->stat |= 8;
+            vid->status |= 8;
         vid->displine++;
         if (vid->displine >= 360)
             vid->displine = 0;
     } else {
         timer_advance_u64(&vid->timer, vid->dispontime);
         if (vid->dispon)
-            vid->stat &= ~1;
+            vid->status &= ~1;
         vid->linepos = 0;
         if (vid->vsynctime) {
             vid->vsynctime--;
             if (!vid->vsynctime)
-                vid->stat &= ~8;
+                vid->status &= ~8;
         }
         if (vid->scanline == (vid->crtc[11] & 31) || ((vid->crtc[8] & 3) == 3 && vid->scanline == ((vid->crtc[11] & 31) >> 1))) {
             vid->cursorvisible  = 0;