diff --git a/src/descriptor.c b/src/descriptor.c
index c4e86ca..72db49a 100644
--- a/src/descriptor.c
+++ b/src/descriptor.c
@@ -208,6 +208,7 @@ static const dc_descriptor_t g_descriptors[] = {
 	{"Oceanic",  "OCi",                 DC_FAMILY_OCEANIC_ATOM2, 0x454B, DC_TRANSPORT_SERIAL, NULL},
 	{"Aeris",    "A300CS",              DC_FAMILY_OCEANIC_ATOM2, 0x454C, DC_TRANSPORT_SERIAL, NULL},
 	{"Beuchat",  "Mundial 3",           DC_FAMILY_OCEANIC_ATOM2, 0x4550, DC_TRANSPORT_SERIAL, NULL},
+	{"Oceanic",  "Pro Plus X",          DC_FAMILY_OCEANIC_ATOM2, 0x4552, DC_TRANSPORT_SERIAL, NULL},
 	{"Oceanic",  "F10",                 DC_FAMILY_OCEANIC_ATOM2, 0x4553, DC_TRANSPORT_SERIAL, NULL},
 	{"Oceanic",  "F11",                 DC_FAMILY_OCEANIC_ATOM2, 0x4554, DC_TRANSPORT_SERIAL, NULL},
 	{"Subgear",  "XP-Air",              DC_FAMILY_OCEANIC_ATOM2, 0x4555, DC_TRANSPORT_SERIAL, NULL},
diff --git a/src/oceanic_atom2.c b/src/oceanic_atom2.c
index f7a9b7a..c33c880 100644
--- a/src/oceanic_atom2.c
+++ b/src/oceanic_atom2.c
@@ -32,6 +32,7 @@
 
 #define ISINSTANCE(device) dc_device_isinstance((device), &oceanic_atom2_device_vtable.base)
 
+#define PROPLUSX   0x4552
 #define VTX        0x4557
 #define I750TC     0x455A
 
@@ -44,6 +45,7 @@
 #define CMD_READ1     0xB1
 #define CMD_READ8     0xB4
 #define CMD_READ16    0xB8
+#define CMD_READ16HI  0xF6
 #define CMD_WRITE     0xB2
 #define CMD_KEEPALIVE 0x91
 #define CMD_QUIT      0x6A
@@ -57,7 +59,8 @@ typedef struct oceanic_atom2_device_t {
 	unsigned int delay;
 	unsigned int bigpage;
 	unsigned char cache[256];
-	unsigned int cached;
+	unsigned int cached_page;
+	unsigned int cached_highmem;
 } oceanic_atom2_device_t;
 
 static dc_status_t oceanic_atom2_device_read (dc_device_t *abstract, unsigned int address, unsigned char data[], unsigned int size);
@@ -184,6 +187,10 @@ static const oceanic_common_version_t oceanic_reactpro_version[] = {
 	{"REACPRO2 \0\0 512K"},
 };
 
+static const oceanic_common_version_t oceanic_proplusx_version[] = {
+	{"OCEANOCX \0\0 2048"},
+};
+
 static const oceanic_common_version_t aeris_a300cs_version[] = {
 	{"AER300CS \0\0 2048"},
 	{"OCEANVTX \0\0 2048"},
@@ -196,6 +203,7 @@ static const oceanic_common_version_t aqualung_i450t_version[] = {
 
 static const oceanic_common_layout_t aeris_f10_layout = {
 	0x10000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0100, /* rb_logbook_begin */
@@ -210,6 +218,7 @@ static const oceanic_common_layout_t aeris_f10_layout = {
 
 static const oceanic_common_layout_t aeris_f11_layout = {
 	0x20000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0100, /* rb_logbook_begin */
@@ -224,6 +233,7 @@ static const oceanic_common_layout_t aeris_f11_layout = {
 
 static const oceanic_common_layout_t oceanic_default_layout = {
 	0x10000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -238,6 +248,7 @@ static const oceanic_common_layout_t oceanic_default_layout = {
 
 static const oceanic_common_layout_t oceanic_atom1_layout = {
 	0x8000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -252,6 +263,7 @@ static const oceanic_common_layout_t oceanic_atom1_layout = {
 
 static const oceanic_common_layout_t oceanic_atom2a_layout = {
 	0xFFF0, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -266,6 +278,7 @@ static const oceanic_common_layout_t oceanic_atom2a_layout = {
 
 static const oceanic_common_layout_t oceanic_atom2b_layout = {
 	0x10000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -280,6 +293,7 @@ static const oceanic_common_layout_t oceanic_atom2b_layout = {
 
 static const oceanic_common_layout_t oceanic_atom2c_layout = {
 	0xFFF0, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -294,6 +308,7 @@ static const oceanic_common_layout_t oceanic_atom2c_layout = {
 
 static const oceanic_common_layout_t sherwood_wisdom_layout = {
 	0xFFF0, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x03D0, /* rb_logbook_begin */
@@ -308,6 +323,7 @@ static const oceanic_common_layout_t sherwood_wisdom_layout = {
 
 static const oceanic_common_layout_t oceanic_proplus3_layout = {
 	0x10000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x03E0, /* rb_logbook_begin */
@@ -322,6 +338,7 @@ static const oceanic_common_layout_t oceanic_proplus3_layout = {
 
 static const oceanic_common_layout_t tusa_zenair_layout = {
 	0xFFF0, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -336,6 +353,7 @@ static const oceanic_common_layout_t tusa_zenair_layout = {
 
 static const oceanic_common_layout_t oceanic_oc1_layout = {
 	0x20000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -350,6 +368,7 @@ static const oceanic_common_layout_t oceanic_oc1_layout = {
 
 static const oceanic_common_layout_t oceanic_oci_layout = {
 	0x20000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x10C0, /* rb_logbook_begin */
@@ -364,6 +383,7 @@ static const oceanic_common_layout_t oceanic_oci_layout = {
 
 static const oceanic_common_layout_t oceanic_atom3_layout = {
 	0x20000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0400, /* rb_logbook_begin */
@@ -378,6 +398,7 @@ static const oceanic_common_layout_t oceanic_atom3_layout = {
 
 static const oceanic_common_layout_t oceanic_vt4_layout = {
 	0x20000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0420, /* rb_logbook_begin */
@@ -392,6 +413,7 @@ static const oceanic_common_layout_t oceanic_vt4_layout = {
 
 static const oceanic_common_layout_t hollis_tx1_layout = {
 	0x40000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0780, /* rb_logbook_begin */
@@ -406,6 +428,7 @@ static const oceanic_common_layout_t hollis_tx1_layout = {
 
 static const oceanic_common_layout_t oceanic_veo1_layout = {
 	0x0400, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0400, /* rb_logbook_begin */
@@ -420,6 +443,7 @@ static const oceanic_common_layout_t oceanic_veo1_layout = {
 
 static const oceanic_common_layout_t oceanic_reactpro_layout = {
 	0xFFF0, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0400, /* rb_logbook_begin */
@@ -432,8 +456,24 @@ static const oceanic_common_layout_t oceanic_reactpro_layout = {
 	1, /* pt_mode_serial */
 };
 
+static const oceanic_common_layout_t oceanic_proplusx_layout = {
+	0x440000, /* memsize */
+	0x40000, /* highmem */
+	0x0000, /* cf_devinfo */
+	0x0040, /* cf_pointers */
+	0x1000, /* rb_logbook_begin */
+	0x10000, /* rb_logbook_end */
+	16, /* rb_logbook_entry_size */
+	0x40000, /* rb_profile_begin */
+	0x440000, /* rb_profile_end */
+	0, /* pt_mode_global */
+	1, /* pt_mode_logbook */
+	0, /* pt_mode_serial */
+};
+
 static const oceanic_common_layout_t aeris_a300cs_layout = {
 	0x40000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0900, /* rb_logbook_begin */
@@ -448,6 +488,7 @@ static const oceanic_common_layout_t aeris_a300cs_layout = {
 
 static const oceanic_common_layout_t aqualung_i450t_layout = {
 	0x40000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x10C0, /* rb_logbook_begin */
@@ -595,12 +636,13 @@ oceanic_atom2_device_open (dc_device_t **out, dc_context_t *context, dc_iostream
 	device->iostream = iostream;
 	device->delay = 0;
 	device->bigpage = 1; // no big pages
-	device->cached = INVALID;
+	device->cached_page = INVALID;
+	device->cached_highmem = INVALID;
 	memset(device->cache, 0, sizeof(device->cache));
 
 	// Get the correct baudrate.
 	unsigned int baudrate = 38400;
-	if (model == VTX || model == I750TC) {
+	if (model == VTX || model == I750TC || model == PROPLUSX) {
 		baudrate = 115200;
 	}
 
@@ -684,6 +726,9 @@ oceanic_atom2_device_open (dc_device_t **out, dc_context_t *context, dc_iostream
 		device->base.layout = &oceanic_veo1_layout;
 	} else if (OCEANIC_COMMON_MATCH (device->base.version, oceanic_reactpro_version)) {
 		device->base.layout = &oceanic_reactpro_layout;
+	} else if (OCEANIC_COMMON_MATCH (device->base.version, oceanic_proplusx_version)) {
+		device->base.layout = &oceanic_proplusx_layout;
+		device->bigpage = 16;
 	} else if (OCEANIC_COMMON_MATCH (device->base.version, aeris_a300cs_version)) {
 		device->base.layout = &aeris_a300cs_layout;
 		device->bigpage = 16;
@@ -779,6 +824,7 @@ static dc_status_t
 oceanic_atom2_device_read (dc_device_t *abstract, unsigned int address, unsigned char data[], unsigned int size)
 {
 	oceanic_atom2_device_t *device = (oceanic_atom2_device_t*) abstract;
+	const oceanic_common_layout_t *layout = device->base.layout;
 
 	if ((address % PAGESIZE != 0) ||
 		(size    % PAGESIZE != 0))
@@ -807,12 +853,26 @@ oceanic_atom2_device_read (dc_device_t *abstract, unsigned int address, unsigned
 	// Pick the best pagesize to use.
 	unsigned int pagesize = device->bigpage * PAGESIZE;
 
+	// High memory state.
+	unsigned int highmem = 0;
+
 	unsigned int nbytes = 0;
 	while (nbytes < size) {
-		unsigned int page = address / pagesize;
-		if (page != device->cached) {
+		// Switch to the correct read command when entering the high memory area.
+		if (layout->highmem && address >= layout->highmem && !highmem) {
+			highmem = layout->highmem;
+			read_cmd = CMD_READ16HI;
+			crc_size = 2;
+			pagesize = 16 * PAGESIZE;
+		}
+
+		// Calculate the page number after mapping the virtual high memory
+		// addresses back to their physical address.
+		unsigned int page = (address - highmem) / pagesize;
+
+		if (page != device->cached_page || highmem != device->cached_highmem) {
 			// Read the package.
-			unsigned int number = page * device->bigpage; // This is always PAGESIZE, even in big page mode.
+			unsigned int number = highmem ? page : page * device->bigpage; // This is always PAGESIZE, even in big page mode.
 			unsigned char answer[256 + 2] = {0};          // Maximum we support for the known commands.
 			unsigned char command[4] = {read_cmd,
 					(number >> 8) & 0xFF, // high
@@ -824,7 +884,8 @@ oceanic_atom2_device_read (dc_device_t *abstract, unsigned int address, unsigned
 
 			// Cache the page.
 			memcpy (device->cache, answer, pagesize);
-			device->cached = page;
+			device->cached_page = page;
+			device->cached_highmem = highmem;
 		}
 
 		unsigned int offset = address % pagesize;
@@ -853,7 +914,8 @@ oceanic_atom2_device_write (dc_device_t *abstract, unsigned int address, const u
 		return DC_STATUS_INVALIDARGS;
 
 	// Invalidate the cache.
-	device->cached = INVALID;
+	device->cached_page = INVALID;
+	device->cached_highmem = INVALID;
 
 	unsigned int nbytes = 0;
 	while (nbytes < size) {
diff --git a/src/oceanic_atom2_parser.c b/src/oceanic_atom2_parser.c
index 0550983..227eae6 100644
--- a/src/oceanic_atom2_parser.c
+++ b/src/oceanic_atom2_parser.c
@@ -75,6 +75,7 @@
 #define OCI         0x454B
 #define A300CS      0x454C
 #define MUNDIAL3    0x4550
+#define PROPLUSX    0x4552
 #define F10B        0x4553
 #define F11B        0x4554
 #define XPAIR       0x4555
@@ -174,6 +175,8 @@ oceanic_atom2_parser_create (dc_parser_t **out, dc_context_t *context, unsigned
 	} else if (model == A300CS || model == VTX ||
 		model == I450T || model == I750TC) {
 		parser->headersize = 5 * PAGESIZE;
+	} else if (model == PROPLUSX) {
+		parser->headersize = 3 * PAGESIZE;
 	}
 
 	parser->cached = 0;
@@ -309,6 +312,7 @@ oceanic_atom2_parser_get_datetime (dc_parser_t *abstract, dc_datetime_t *datetim
 		case VTX:
 		case I450T:
 		case I750TC:
+		case PROPLUSX:
 			datetime->year   = (p[10]) + 2000;
 			datetime->month  = (p[8]);
 			datetime->day    = (p[9]);
@@ -622,7 +626,8 @@ oceanic_atom2_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_
 	if (parser->mode != FREEDIVE) {
 		unsigned int idx = 0x17;
 		if (parser->model == A300CS || parser->model == VTX ||
-			parser->model == I450T || parser->model == I750TC)
+			parser->model == I450T || parser->model == I750TC ||
+			parser->model == PROPLUSX)
 			idx = 0x1f;
 		switch (data[idx] & 0x03) {
 		case 0:
@@ -677,7 +682,7 @@ oceanic_atom2_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_
 		parser->model == OC1C || parser->model == OCI ||
 		parser->model == TX1 || parser->model == A300CS ||
 		parser->model == VTX || parser->model == I450T ||
-		parser->model == I750TC) {
+		parser->model == I750TC || parser->model == PROPLUSX) {
 		samplesize = PAGESIZE;
 	}
 
@@ -855,7 +860,7 @@ oceanic_atom2_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_
 					parser->model == XPAIR) {
 					temperature = ((data[offset + 7] & 0xF0) >> 4) | ((data[offset + 7] & 0x0C) << 2) | ((data[offset + 5] & 0x0C) << 4);
 				} else if (parser->model == A300CS || parser->model == VTX ||
-					parser->model == I750TC) {
+					parser->model == I750TC || parser->model == PROPLUSX) {
 					temperature = data[offset + 11];
 				} else {
 					unsigned int sign;
@@ -895,7 +900,8 @@ oceanic_atom2_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_
 					parser->model == VISION || parser->model == XPAIR)
 					pressure = (((data[offset + 0] & 0x03) << 8) + data[offset + 1]) * 5;
 				else if (parser->model == TX1 || parser->model == A300CS ||
-					parser->model == VTX || parser->model == I750TC)
+					parser->model == VTX || parser->model == I750TC ||
+					parser->model == PROPLUSX)
 					pressure = array_uint16_le (data + offset + 4);
 				else
 					pressure -= data[offset + 1];
@@ -943,7 +949,8 @@ oceanic_atom2_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_
 			unsigned int have_deco = 0;
 			unsigned int decostop = 0, decotime = 0;
 			if (parser->model == A300CS || parser->model == VTX ||
-				parser->model == I450T || parser->model == I750TC) {
+				parser->model == I450T || parser->model == I750TC ||
+				parser->model == PROPLUSX) {
 				decostop = (data[offset + 15] & 0x70) >> 4;
 				decotime = array_uint16_le(data + offset + 6) & 0x03FF;
 				have_deco = 1;
@@ -986,7 +993,7 @@ oceanic_atom2_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_
 				have_rbt = 1;
 			} else if (parser->model == I450T || parser->model == OC1A ||
 				parser->model == OC1B || parser->model == OC1C ||
-				parser->model == OCI) {
+				parser->model == OCI || parser->model == PROPLUSX) {
 				rbt = array_uint16_le(data + offset + 8) & 0x01FF;
 				have_rbt = 1;
 			} else if (parser->model == VISION || parser->model == XPAIR ||
diff --git a/src/oceanic_common.c b/src/oceanic_common.c
index 9f7341a..908896c 100644
--- a/src/oceanic_common.c
+++ b/src/oceanic_common.c
@@ -41,7 +41,7 @@
 #define INVALID 0
 
 static unsigned int
-get_profile_first (const unsigned char data[], const oceanic_common_layout_t *layout)
+get_profile_first (const unsigned char data[], const oceanic_common_layout_t *layout, unsigned int pagesize)
 {
 	unsigned int value;
 
@@ -55,17 +55,22 @@ get_profile_first (const unsigned char data[], const oceanic_common_layout_t *la
 		return array_uint16_le (data + 16);
 	}
 
-	if (layout->memsize > 0x20000)
-		return (value & 0x3FFF) * PAGESIZE;
-	else if (layout->memsize > 0x10000)
-		return (value & 0x1FFF) * PAGESIZE;
-	else
-		return (value & 0x0FFF) * PAGESIZE;
+	unsigned int npages = (layout->memsize - layout->highmem) / pagesize;
+
+	if (npages > 0x2000) {
+		value &= 0x3FFF;
+	}  else if (npages > 0x1000) {
+		value &= 0x1FFF;
+	} else {
+		value &= 0x0FFF;
+	}
+
+	return layout->highmem + value * pagesize;
 }
 
 
 static unsigned int
-get_profile_last (const unsigned char data[], const oceanic_common_layout_t *layout)
+get_profile_last (const unsigned char data[], const oceanic_common_layout_t *layout, unsigned int pagesize)
 {
 	unsigned int value;
 
@@ -79,12 +84,17 @@ get_profile_last (const unsigned char data[], const oceanic_common_layout_t *lay
 		return array_uint16_le(data + 18);
 	}
 
-	if (layout->memsize > 0x20000)
-		return (value & 0x3FFF) * PAGESIZE;
-	else if (layout->memsize > 0x10000)
-		return (value & 0x1FFF) * PAGESIZE;
-	else
-		return (value & 0x0FFF) * PAGESIZE;
+	unsigned int npages = (layout->memsize - layout->highmem) / pagesize;
+
+	if (npages > 0x2000) {
+		value &= 0x3FFF;
+	} else if (npages > 0x1000) {
+		value &= 0x1FFF;
+	} else {
+		value &= 0x0FFF;
+	}
+
+	return layout->highmem + value * pagesize;
 }
 
 
@@ -330,6 +340,9 @@ oceanic_common_device_profile (dc_device_t *abstract, dc_event_progress_t *progr
 
 	const oceanic_common_layout_t *layout = device->layout;
 
+	// Get the pagesize
+	unsigned int pagesize = layout->highmem ? 16 * PAGESIZE : PAGESIZE;
+
 	// Cache the logbook pointer and size.
 	const unsigned char *logbooks = dc_buffer_get_data (logbook);
 	unsigned int rb_logbook_size = dc_buffer_get_size (logbook);
@@ -352,8 +365,8 @@ oceanic_common_device_profile (dc_device_t *abstract, dc_event_progress_t *progr
 		entry -= layout->rb_logbook_entry_size;
 
 		// Get the profile pointers.
-		unsigned int rb_entry_first = get_profile_first (logbooks + entry, layout);
-		unsigned int rb_entry_last  = get_profile_last (logbooks + entry, layout);
+		unsigned int rb_entry_first = get_profile_first (logbooks + entry, layout, pagesize);
+		unsigned int rb_entry_last  = get_profile_last (logbooks + entry, layout, pagesize);
 		if (rb_entry_first < layout->rb_profile_begin ||
 			rb_entry_first >= layout->rb_profile_end ||
 			rb_entry_last < layout->rb_profile_begin ||
@@ -365,8 +378,8 @@ oceanic_common_device_profile (dc_device_t *abstract, dc_event_progress_t *progr
 		}
 
 		// Calculate the end pointer and the number of bytes.
-		unsigned int rb_entry_end   = RB_PROFILE_INCR (rb_entry_last, PAGESIZE, layout);
-		unsigned int rb_entry_size  = RB_PROFILE_DISTANCE (rb_entry_first, rb_entry_last, layout) + PAGESIZE;
+		unsigned int rb_entry_end   = RB_PROFILE_INCR (rb_entry_last, pagesize, layout);
+		unsigned int rb_entry_size  = RB_PROFILE_DISTANCE (rb_entry_first, rb_entry_last, layout) + pagesize;
 
 		// Take the end pointer of the most recent logbook entry as the
 		// end of profile pointer.
@@ -430,8 +443,8 @@ oceanic_common_device_profile (dc_device_t *abstract, dc_event_progress_t *progr
 		entry -= layout->rb_logbook_entry_size;
 
 		// Get the profile pointers.
-		unsigned int rb_entry_first = get_profile_first (logbooks + entry, layout);
-		unsigned int rb_entry_last  = get_profile_last (logbooks + entry, layout);
+		unsigned int rb_entry_first = get_profile_first (logbooks + entry, layout, pagesize);
+		unsigned int rb_entry_last  = get_profile_last (logbooks + entry, layout, pagesize);
 		if (rb_entry_first < layout->rb_profile_begin ||
 			rb_entry_first >= layout->rb_profile_end ||
 			rb_entry_last < layout->rb_profile_begin ||
@@ -445,8 +458,8 @@ oceanic_common_device_profile (dc_device_t *abstract, dc_event_progress_t *progr
 		}
 
 		// Calculate the end pointer and the number of bytes.
-		unsigned int rb_entry_end   = RB_PROFILE_INCR (rb_entry_last, PAGESIZE, layout);
-		unsigned int rb_entry_size  = RB_PROFILE_DISTANCE (rb_entry_first, rb_entry_last, layout) + PAGESIZE;
+		unsigned int rb_entry_end   = RB_PROFILE_INCR (rb_entry_last, pagesize, layout);
+		unsigned int rb_entry_size  = RB_PROFILE_DISTANCE (rb_entry_first, rb_entry_last, layout) + pagesize;
 
 		// Skip gaps between the profiles.
 		unsigned int gap = 0;
@@ -481,6 +494,14 @@ oceanic_common_device_profile (dc_device_t *abstract, dc_event_progress_t *progr
 		offset -= layout->rb_logbook_entry_size;
 		memcpy (profiles + offset, logbooks + entry, layout->rb_logbook_entry_size);
 
+		// Remove padding from the profile.
+		if (layout->highmem) {
+			unsigned char *profile = profiles + offset + layout->rb_logbook_entry_size;
+			while (rb_entry_size >= PAGESIZE && array_isequal (profile + rb_entry_size - PAGESIZE, PAGESIZE, 0xFF)) {
+				rb_entry_size -= PAGESIZE;
+			}
+		}
+
 		unsigned char *p = profiles + offset;
 		if (callback && !callback (p, rb_entry_size + layout->rb_logbook_entry_size, p, layout->rb_logbook_entry_size, userdata)) {
 			break;
diff --git a/src/oceanic_common.h b/src/oceanic_common.h
index 1b8ed08..a5c55b8 100644
--- a/src/oceanic_common.h
+++ b/src/oceanic_common.h
@@ -38,6 +38,7 @@ extern "C" {
 typedef struct oceanic_common_layout_t {
 	// Memory size.
 	unsigned int memsize;
+	unsigned int highmem;
 	// Device info.
 	unsigned int cf_devinfo;
 	// Ringbuffer pointers.
diff --git a/src/oceanic_veo250.c b/src/oceanic_veo250.c
index 42cb676..de70c7b 100644
--- a/src/oceanic_veo250.c
+++ b/src/oceanic_veo250.c
@@ -75,6 +75,7 @@ static const oceanic_common_version_t oceanic_veo250_version[] = {
 
 static const oceanic_common_layout_t oceanic_veo250_layout = {
 	0x8000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0400, /* rb_logbook_begin */
diff --git a/src/oceanic_vtpro.c b/src/oceanic_vtpro.c
index 2c9298b..d3387f2 100644
--- a/src/oceanic_vtpro.c
+++ b/src/oceanic_vtpro.c
@@ -89,6 +89,7 @@ static const oceanic_common_version_t oceanic_wisdom_version[] = {
 
 static const oceanic_common_layout_t oceanic_vtpro_layout = {
 	0x8000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x0240, /* rb_logbook_begin */
@@ -103,6 +104,7 @@ static const oceanic_common_layout_t oceanic_vtpro_layout = {
 
 static const oceanic_common_layout_t oceanic_wisdom_layout = {
 	0x8000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0040, /* cf_pointers */
 	0x03D0, /* rb_logbook_begin */
@@ -117,6 +119,7 @@ static const oceanic_common_layout_t oceanic_wisdom_layout = {
 
 static const oceanic_common_layout_t aeris_500ai_layout = {
 	0x20000, /* memsize */
+	0, /* highmem */
 	0x0000, /* cf_devinfo */
 	0x0110, /* cf_pointers */
 	0x0200, /* rb_logbook_begin */