diff --git a/src/devices/sound/aica.cpp b/src/devices/sound/aica.cpp
index f636f209576..24b114719f7 100644
--- a/src/devices/sound/aica.cpp
+++ b/src/devices/sound/aica.cpp
@@ -913,7 +913,10 @@ void aica_device::w16(address_space &space,unsigned int addr,unsigned short val)
 		if(addr<0x3200) //COEF
 			*((unsigned short *) (m_DSP.COEF+(addr-0x3000)/2))=val;
 		else if(addr<0x3400)
+		{
+			assert(((addr-0x3200)/2) < ARRAY_LENGTH(m_DSP.MADRS));
 			*((unsigned short *) (m_DSP.MADRS+(addr-0x3200)/2))=val;
+		}
 		else if(addr<0x3c00)
 		{
 			*((unsigned short *) (m_DSP.MPRO+(addr-0x3400)/2))=val;
@@ -975,6 +978,7 @@ unsigned short aica_device::r16(address_space &space, unsigned int addr)
 		else if (addr < 0x28be)
 		{
 			UpdateRegR(space, addr&0xff);
+			assert((addr&0xff) < ARRAY_LENGTH(m_udata.datab));
 			v= *((unsigned short *) (m_udata.datab+((addr&0xff))));
 			if((addr&0xfffe)==0x2810) m_udata.data[0x10/2] &= 0x7FFF;   // reset LP on read
 		}
@@ -993,7 +997,10 @@ unsigned short aica_device::r16(address_space &space, unsigned int addr)
 		if(addr<0x3200) //COEF
 			v= *((unsigned short *) (m_DSP.COEF+(addr-0x3000)/2));
 		else if(addr<0x3400)
+		{
+			assert(((addr-0x3200)/2) < ARRAY_LENGTH(m_DSP.MADRS));
 			v= *((unsigned short *) (m_DSP.MADRS+(addr-0x3200)/2));
+		}
 		else if(addr<0x3c00)
 			v= *((unsigned short *) (m_DSP.MPRO+(addr-0x3400)/2));
 		else if(addr<0x4000)
diff --git a/src/devices/video/hp1ll3.cpp b/src/devices/video/hp1ll3.cpp
index ada8f48404d..dc6164cbbc2 100644
--- a/src/devices/video/hp1ll3.cpp
+++ b/src/devices/video/hp1ll3.cpp
@@ -551,6 +551,7 @@ WRITE8_MEMBER( hp1ll3_device::write )
 		switch (m_command)
 		{
 		case CONF:
+			assert((m_conf_ptr >> 1) < ARRAY_LENGTH(m_conf));
 			if (m_conf_ptr & 1) {
 				m_conf[m_conf_ptr >> 1] |= data;
 			} else {
diff --git a/src/mame/drivers/vis.cpp b/src/mame/drivers/vis.cpp
index 5a8399db147..f4fb764b02f 100644
--- a/src/mame/drivers/vis.cpp
+++ b/src/mame/drivers/vis.cpp
@@ -535,6 +535,7 @@ WRITE8_MEMBER(vis_vga_device::vga_w)
 			break;
 		case 0x05:
 		case 0x25:
+			assert(vga.crtc.index < ARRAY_LENGTH(m_crtc_regs));
 			m_crtc_regs[vga.crtc.index] = data;
 			switch(vga.crtc.index)
 			{
diff --git a/src/mame/video/k054156_k054157_k056832.cpp b/src/mame/video/k054156_k054157_k056832.cpp
index ef56418616d..9bde7c4f214 100644
--- a/src/mame/video/k054156_k054157_k056832.cpp
+++ b/src/mame/video/k054156_k054157_k056832.cpp
@@ -1149,6 +1149,7 @@ WRITE32_MEMBER( k056832_device::long_w )
 
 WRITE16_MEMBER( k056832_device::b_word_w )
 {
+	assert(offset < ARRAY_LENGTH(m_regsb));
 	COMBINE_DATA(&m_regsb[offset]);
 }