diff --git a/src/ints/int10.h b/src/ints/int10.h
index 2ba402e0..f9b945f2 100644
--- a/src/ints/int10.h
+++ b/src/ints/int10.h
@@ -16,7 +16,12 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
+#ifndef DOSBOX_INT10_H
+#define DOSBOX_INT10_H
 
+#include "dosbox.h"
+
+#include "mem.h"
 #include "vga.h"
 
 #define S3_LFB_BASE		0xC0000000
@@ -237,3 +242,5 @@ bool INT10_VideoState_Restore(Bitu state,RealPt buffer);
 /* Video Parameter Tables */
 Bit16u INT10_SetupVideoParameterTable(PhysPt basepos);
 void INT10_SetupBasicVideoParameterTable(void);
+
+#endif
diff --git a/src/ints/int10_modes.cpp b/src/ints/int10_modes.cpp
index f956ab18..f11eaf5b 100644
--- a/src/ints/int10_modes.cpp
+++ b/src/ints/int10_modes.cpp
@@ -16,14 +16,12 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
-
-#include <string.h>
-
-#include "dosbox.h"
-#include "mem.h"
-#include "inout.h"
 #include "int10.h"
-#include "vga.h"
+
+#include <cassert>
+#include <cstring>
+
+#include "inout.h"
 
 #define _EGA_HALF_CLOCK		0x0001
 #define _EGA_LINE_DOUBLE	0x0002
@@ -512,7 +510,8 @@ static void FinishSetMode(bool clearmem) {
 	}
 }
 
-bool INT10_SetVideoMode_OTHER(Bit16u mode,bool clearmem) {
+static bool INT10_SetVideoMode_OTHER(Bit16u mode, bool clearmem)
+{
 	switch (machine) {
 	case MCH_CGA:
 		if (mode>6) return false;
@@ -534,6 +533,12 @@ bool INT10_SetVideoMode_OTHER(Bit16u mode,bool clearmem) {
 		CurMode=&Hercules_Mode;
 		mode=7; // in case the video parameter table is modified
 		break;
+	case MCH_EGA:
+	case MCH_VGA:
+		// This code should be unreachable, as MCH_EGA and MCH_VGA are
+		// handled in function INT10_SetVideoMode.
+		assert(false);
+		break;
 	}
 	LOG(LOG_INT10,LOG_NORMAL)("Set Video Mode %X",mode);
 
@@ -680,6 +685,12 @@ bool INT10_SetVideoMode_OTHER(Bit16u mode,bool clearmem) {
 		INT10_SetColorSelect(1);
 		INT10_SetBackgroundBorder(0);
 		break;
+	case MCH_EGA:
+	case MCH_VGA:
+		// This code should be unreachable, as MCH_EGA and MCH_VGA are
+		// handled in function INT10_SetVideoMode.
+		assert(false);
+		break;
 	}
 
 	RealPt vparams = RealGetVec(0x1d);
@@ -702,9 +713,10 @@ bool INT10_SetVideoMode_OTHER(Bit16u mode,bool clearmem) {
 	return true;
 }
 
-
-bool INT10_SetVideoMode(Bit16u mode) {
-	bool clearmem=true;Bitu i;
+bool INT10_SetVideoMode(Bit16u mode)
+{
+	bool clearmem = true;
+	Bitu i;
 	if (mode>=0x100) {
 		if ((mode & 0x4000) && int10.vesa_nolfb) return false;
 		if (mode & 0x8000) clearmem=false;
@@ -716,7 +728,9 @@ bool INT10_SetVideoMode(Bit16u mode) {
 	}
 	int10.vesa_setmode=0xffff;
 	LOG(LOG_INT10,LOG_NORMAL)("Set Video Mode %X",mode);
-	if (!IS_EGAVGA_ARCH) return INT10_SetVideoMode_OTHER(mode,clearmem);
+
+	if (!IS_EGAVGA_ARCH)
+		return INT10_SetVideoMode_OTHER(mode, clearmem);
 
 	/* First read mode setup settings from bios area */
 //	Bit8u video_ctl=real_readb(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL);
@@ -829,6 +843,18 @@ bool INT10_SetVideoMode(Bit16u mode) {
 		seq_data[2]|=0xf;				//Enable all planes for writing
 		seq_data[4]|=0xc;				//Graphics - odd/even - Chained
 		break;
+	case M_CGA16:      // only in MCH_CGA
+	case M_TANDY2:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	case M_TANDY4:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	case M_TANDY16:    // only in MCH_TANDY, MCH_PCJR
+	case M_TANDY_TEXT: // only in MCH_CGA, MCH_TANDY
+	case M_HERC_TEXT:  // only in MCH_HERC
+	case M_HERC_GFX:   // only in MCH_HERC
+	case M_ERROR:
+		// This code should be unreachable, as this function deals only
+		// with MCH_EGA and MCH_VGA.
+		assert(false); 
+		break;
 	}
 	for (Bit8u ct=0;ct<SEQ_REGS;ct++) {
 		IO_Write(0x3c4,ct);
@@ -1058,6 +1084,18 @@ bool INT10_SetVideoMode(Bit16u mode) {
 		if (CurMode->special & _VGA_PIXEL_DOUBLE)
 			mode_control |= 0x08;
 		break;
+	case M_CGA16:      // only in MCH_CGA
+	case M_TANDY2:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	case M_TANDY4:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	case M_TANDY16:    // only in MCH_TANDY, MCH_PCJR
+	case M_TANDY_TEXT: // only in MCH_CGA, MCH_TANDY
+	case M_HERC_TEXT:  // only in MCH_HERC
+	case M_HERC_GFX:   // only in MCH_HERC
+	case M_ERROR:
+		// This code should be unreachable, as this function deals only
+		// with MCH_EGA and MCH_VGA.
+		assert(false); 
+		break;
 	}
 
 	IO_Write(crtc_base,0x17);IO_Write(crtc_base+1,mode_control);
@@ -1134,6 +1172,18 @@ bool INT10_SetVideoMode(Bit16u mode) {
 			gfx_data[0x6]|=0x0f;		//graphics mode at at 0xb800=0xbfff
 		}
 		break;
+	case M_CGA16:      // only in MCH_CGA
+	case M_TANDY2:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	case M_TANDY4:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	case M_TANDY16:    // only in MCH_TANDY, MCH_PCJR
+	case M_TANDY_TEXT: // only in MCH_CGA, MCH_TANDY
+	case M_HERC_TEXT:  // only in MCH_HERC
+	case M_HERC_GFX:   // only in MCH_HERC
+	case M_ERROR:
+		// This code should be unreachable, as this function deals only
+		// with MCH_EGA and MCH_VGA.
+		assert(false); 
+		break;
 	}
 	for (Bit8u ct=0;ct<GFX_REGS;ct++) {
 		IO_Write(0x3ce,ct);
@@ -1175,6 +1225,9 @@ bool INT10_SetVideoMode(Bit16u mode) {
 		}
 		break;
 	case M_TANDY16:
+		// TODO: TANDY_16 seems like an oversight here, as
+		//       this function is supposed to deal with
+		//       MCH_EGA and MCH_VGA only.
 		att_data[0x10]=0x01;		//Color Graphics
 		for (Bit8u ct=0;ct<16;ct++) att_data[ct]=ct;
 		break;
@@ -1232,6 +1285,18 @@ att_text16:
 		for (Bit8u ct=0;ct<16;ct++) att_data[ct]=ct;
 		att_data[0x10]=0x41;		//Color Graphics 8-bit
 		break;
+	case M_CGA16:      // only in MCH_CGA
+	case M_TANDY2:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	case M_TANDY4:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+	// case M_TANDY16:    // only in MCH_TANDY, MCH_PCJR
+	case M_TANDY_TEXT: // only in MCH_CGA, MCH_TANDY
+	case M_HERC_TEXT:  // only in MCH_HERC
+	case M_HERC_GFX:   // only in MCH_HERC
+	case M_ERROR:
+		// This code should be unreachable, as this function deals only
+		// with MCH_EGA and MCH_VGA.
+		assert(false); 
+		break;
 	}
 	IO_Read(mono_mode ? 0x3ba : 0x3da);
 	if ((modeset_ctl & 8)==0) {
@@ -1265,6 +1330,9 @@ att_text16:
 		case M_CGA2:
 		case M_CGA4:
 		case M_TANDY16:
+			// TODO: TANDY_16 seems like an oversight here, as
+			//       this function is supposed to deal with
+			//       MCH_EGA and MCH_VGA only.
 			for (i=0;i<64;i++) {
 				IO_Write(0x3c9,cga_palette_2[i][0]);
 				IO_Write(0x3c9,cga_palette_2[i][1]);
@@ -1310,6 +1378,18 @@ dac_text16:
 				IO_Write(0x3c9,vga_palette[i][2]);
 			}
 			break;
+		case M_CGA16:      // only in MCH_CGA
+		case M_TANDY2:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+		case M_TANDY4:     // only in MCH_CGA, MCH_TANDY, MCH_PCJR
+		// case M_TANDY16:    // only in MCH_TANDY, MCH_PCJR
+		case M_TANDY_TEXT: // only in MCH_CGA, MCH_TANDY
+		case M_HERC_TEXT:  // only in MCH_HERC
+		case M_HERC_GFX:   // only in MCH_HERC
+		case M_ERROR:
+			// This code should be unreachable, as this function deals only
+			// with MCH_EGA and MCH_VGA.
+			assert(false); 
+			break;
 		}
 		if (IS_VGA_ARCH) {
 			/* check if gray scale summing is enabled */