diff --git a/src/lib/formats/cassimg.c b/src/lib/formats/cassimg.c
index 0b428272ed5..b7f1ea68ccd 100644
--- a/src/lib/formats/cassimg.c
+++ b/src/lib/formats/cassimg.c
@@ -855,9 +855,9 @@ casserr_t cassette_legacy_construct(cassette_image *cassette,
 	casserr_t err;
 	int length;
 	int sample_count;
-	void *bytes = NULL;
-	void *chunk = NULL;
-	INT16 *samples = NULL;
+	dynamic_buffer bytes;
+	dynamic_buffer chunk;
+	dynamic_array<INT16> samples;
 	int pos = 0;
 	UINT64 offset = 0;
 	UINT64 size;
@@ -880,12 +880,7 @@ casserr_t cassette_legacy_construct(cassette_image *cassette,
 		args.sample_frequency = 11025;
 
 	/* allocate a buffer for the binary data */
-	chunk = malloc(args.chunk_size);
-	if (!chunk)
-	{
-		err = CASSETTE_ERROR_OUTOFMEMORY;
-		goto done;
-	}
+	chunk.resize(args.chunk_size);
 
 	/* determine number of samples */
 	if (args.chunk_sample_calc)
@@ -896,14 +891,9 @@ casserr_t cassette_legacy_construct(cassette_image *cassette,
 			goto done;
 		}
 
-		bytes = malloc(size);
-		if (!bytes)
-		{
-			err = CASSETTE_ERROR_OUTOFMEMORY;
-			goto done;
-		}
+		bytes.resize(size);
 		cassette_image_read(cassette, bytes, 0, size);
-		sample_count = args.chunk_sample_calc((const UINT8*)bytes, (int) size);
+		sample_count = args.chunk_sample_calc(bytes, (int)size);
 
 		if (args.header_samples < 0)
 			args.header_samples = sample_count;
@@ -916,12 +906,7 @@ casserr_t cassette_legacy_construct(cassette_image *cassette,
 	sample_count += args.header_samples + args.trailer_samples;
 
 	/* allocate a buffer for the completed samples */
-	samples = (INT16*)malloc(sample_count * sizeof(*samples));
-	if (!samples)
-	{
-		err = CASSETTE_ERROR_OUTOFMEMORY;
-		goto done;
-	}
+	samples.resize(sample_count);
 
 	/* if there has to be a header */
 	if (args.header_samples > 0)
@@ -941,7 +926,7 @@ casserr_t cassette_legacy_construct(cassette_image *cassette,
 		cassette_image_read(cassette, chunk, offset, args.chunk_size);
 		offset += args.chunk_size;
 
-		length = args.fill_wave(samples + pos, sample_count - pos, (UINT8*)chunk);
+		length = args.fill_wave(samples + pos, sample_count - pos, chunk);
 		if (length < 0)
 		{
 			err = CASSETTE_ERROR_INVALIDIMAGE;
@@ -978,12 +963,6 @@ casserr_t cassette_legacy_construct(cassette_image *cassette,
 #endif
 
 done:
-	if (samples)
-		free(samples);
-	if (chunk)
-		free(chunk);
-	if (bytes)
-		free(bytes);
 	return err;
 }
 
diff --git a/src/lib/formats/coco_dsk.c b/src/lib/formats/coco_dsk.c
index 2ab89bae312..d781e89770d 100644
--- a/src/lib/formats/coco_dsk.c
+++ b/src/lib/formats/coco_dsk.c
@@ -13,6 +13,7 @@
 #include "formats/coco_dsk.h"
 #include "formats/basicdsk.h"
 #include "imageutl.h"
+#include "coretmpl.h"
 
 /* -----------------------------------------------------------------------
  * JVC (Jeff Vavasour CoCo) format
@@ -719,7 +720,7 @@ static floperr_t coco_dmk_format_track(floppy_image_legacy *floppy, int head, in
 	UINT8 *track_data;
 	void *track_data_v;
 	UINT32 max_track_size;
-	int *sector_map = NULL;
+	dynamic_array<int> sector_map;
 
 	sectors         = option_resolution_lookup_int(params, PARAM_SECTORS);
 	sector_length   = option_resolution_lookup_int(params, PARAM_SECTOR_LENGTH);
@@ -746,13 +747,8 @@ static floperr_t coco_dmk_format_track(floppy_image_legacy *floppy, int head, in
 	track_data = (UINT8 *) track_data_v;
 
 	/* set up sector map */
-	sector_map = (int*)malloc(sectors * sizeof(*sector_map));
-	if (!sector_map)
-	{
-		err = FLOPPY_ERROR_OUTOFMEMORY;
-		goto done;
-	}
-	memset(sector_map, 0xFF, sectors * sizeof(*sector_map));
+	sector_map.resize(sectors);
+	sector_map.clear(0xFF);
 
 	physical_sector = 0;
 	for (logical_sector = 0; logical_sector < sectors; logical_sector++)
@@ -837,8 +833,6 @@ static floperr_t coco_dmk_format_track(floppy_image_legacy *floppy, int head, in
 	memset(&track_data[track_position], 0x4e, max_track_size - track_position);
 
 done:
-	if (sector_map)
-		free(sector_map);
 	return err;
 }
 
diff --git a/src/lib/formats/csw_cas.c b/src/lib/formats/csw_cas.c
index c587a9c087e..f7b542fd1bb 100644
--- a/src/lib/formats/csw_cas.c
+++ b/src/lib/formats/csw_cas.c
@@ -49,7 +49,7 @@ static int csw_cas_to_wav_size( const UINT8 *casdata, int caslen )
 	UINT8  CompressionType;
 	UINT8  Flags;
 	UINT8  HeaderExtensionLength;
-	UINT8  *gz_ptr = NULL;
+	dynamic_buffer gz_ptr;
 
 	int         total_size;
 	z_stream    d_stream;
@@ -97,8 +97,7 @@ static int csw_cas_to_wav_size( const UINT8 *casdata, int caslen )
 	//from here on down for now I am assuming it is compressed csw file.
 	in_ptr = (UINT8*) casdata+0x34+HeaderExtensionLength;
 
-	gz_ptr = (UINT8*)malloc( 8 );
-
+	gz_ptr.resize( 8 );
 
 	d_stream.next_in = (unsigned char *)in_ptr;
 	d_stream.avail_in = caslen - ( in_ptr - casdata );
@@ -155,20 +154,9 @@ static int csw_cas_to_wav_size( const UINT8 *casdata, int caslen )
 		goto cleanup;
 	}
 
-	if ( gz_ptr )
-	{
-		free( gz_ptr );
-		gz_ptr = NULL;
-	}
-
 	return total_size;
 
 cleanup:
-	if ( gz_ptr )
-	{
-		free( gz_ptr );
-		gz_ptr = NULL;
-	}
 	return -1;
 }
 
@@ -181,7 +169,7 @@ static int csw_cas_fill_wave( INT16 *buffer, int length, UINT8 *bytes )
 	UINT8  HeaderExtensionLength;
 	INT8   Bit;
 
-	UINT8 *gz_ptr = NULL;
+	dynamic_buffer gz_ptr;
 	int         total_size;
 	z_stream    d_stream;
 	int         err;
@@ -217,7 +205,7 @@ static int csw_cas_fill_wave( INT16 *buffer, int length, UINT8 *bytes )
 	//from here on down for now I am assuming it is compressed csw file.
 	in_ptr = (UINT8*) bytes+0x34+HeaderExtensionLength;
 
-	gz_ptr = (UINT8*)malloc( 8 );
+	gz_ptr.resize( 8 );
 
 	d_stream.next_in = (unsigned char *)in_ptr;
 	d_stream.avail_in = mycaslen - ( in_ptr - bytes );
@@ -278,20 +266,9 @@ static int csw_cas_fill_wave( INT16 *buffer, int length, UINT8 *bytes )
 		goto cleanup;
 	}
 
-	if ( gz_ptr )
-	{
-		free( gz_ptr );
-		gz_ptr = NULL;
-	}
-
 	return length;
 
 cleanup:
-	if ( gz_ptr )
-	{
-		free( gz_ptr );
-		gz_ptr = NULL;
-	}
 	return -1;
 }
 
diff --git a/src/lib/formats/kc_cas.c b/src/lib/formats/kc_cas.c
index 7d98a1bf53c..9198a98c4d5 100644
--- a/src/lib/formats/kc_cas.c
+++ b/src/lib/formats/kc_cas.c
@@ -210,7 +210,7 @@ static int kc_handle_tap(INT16 *buffer, const UINT8 *casdata)
 
 static int kc_handle_sss(INT16 *buffer, const UINT8 *casdata)
 {
-	UINT8 *sss = (UINT8*)malloc(kc_image_size + 11);
+	dynamic_buffer sss(kc_image_size + 11);
 
 	// tries to generate the missing head
 	memset(sss + 0, 0xd3, 3);
@@ -222,8 +222,6 @@ static int kc_handle_sss(INT16 *buffer, const UINT8 *casdata)
 
 	int retval = kc_handle_cass(buffer, sss, KC_IMAGE_KCC);
 
-	free(sss);
-
 	return retval;
 }
 
diff --git a/src/lib/formats/ti99_dsk.c b/src/lib/formats/ti99_dsk.c
index a80c3d84594..b1b8cec589b 100644
--- a/src/lib/formats/ti99_dsk.c
+++ b/src/lib/formats/ti99_dsk.c
@@ -1647,9 +1647,8 @@ static floperr_t ti99_sdf_write_track(floppy_image_legacy *floppy, int head, int
 */
 /* static floperr_t ti99_sdf_format_track(floppy_image_legacy *floppy, int head, int track, option_resolution *params)
 {
-    UINT8 *sector0 = (UINT8*)malloc(SECTOR_SIZE);
+    dynamic_buffer sector0(SECTOR_SIZE);
     create_vib(sector0, params);
-    free(sector0);
     if (true)
     {
         printf("not implemented\n");
@@ -2297,11 +2296,9 @@ static floperr_t ti99_tdf_read_sector(floppy_image_legacy *floppy, int head, int
 {
 	floperr_t err;
 	UINT8 *sector_data;
-	UINT8 *track_data;
 	int imgtrack = track;
 	struct ti99dsk_tag *tag = (ti99dsk_tag*)floppy_tag(floppy);
-
-	track_data = (UINT8*)malloc(tag->track_size);
+	dynamic_buffer track_data(tag->track_size);
 
 	if (use_80_track_drives && tag->tracks<=40)
 	{
@@ -2318,7 +2315,6 @@ static floperr_t ti99_tdf_read_sector(floppy_image_legacy *floppy, int head, int
 	/* verify CRC? */
 
 	memcpy(buffer, sector_data, SECTOR_SIZE);
-	free(track_data);
 	return FLOPPY_ERROR_SUCCESS;
 }
 
@@ -2376,7 +2372,7 @@ static floperr_t ti99_tdf_write_indexed_sector(floppy_image_legacy *floppy, int
 	/* Read track, head */
 	int byte;
 	struct ti99dsk_tag *tag = (ti99dsk_tag*)floppy_tag(floppy);
-	UINT8 *track_data;
+	dynamic_buffer track_data(tag->track_size);
 	UINT8 *sector_data;
 	UINT64 track_offset;
 	UINT64 offset;
@@ -2388,8 +2384,6 @@ static floperr_t ti99_tdf_write_indexed_sector(floppy_image_legacy *floppy, int
 	int i;
 	floperr_t err;
 
-	track_data = (UINT8*)malloc(tag->track_size);
-
 	if (use_80_track_drives && tag->tracks<=40)
 	{
 		imgtrack = track / 2;
@@ -2398,7 +2392,6 @@ static floperr_t ti99_tdf_write_indexed_sector(floppy_image_legacy *floppy, int
 	err = ti99_tdf_read_track_internal(floppy, head, imgtrack, 0, track_data, tag->track_size);
 	if (err)
 	{
-		free(track_data);
 		return err;
 	}
 
@@ -2407,7 +2400,6 @@ static floperr_t ti99_tdf_write_indexed_sector(floppy_image_legacy *floppy, int
 	{
 		if (determine_offset(tag->format, track_data, &tag->first_idam)==FLOPPY_ERROR_SEEKERROR)
 		{
-			free(track_data);
 			return FLOPPY_ERROR_SEEKERROR;
 		}
 	}
@@ -2428,7 +2420,6 @@ static floperr_t ti99_tdf_write_indexed_sector(floppy_image_legacy *floppy, int
 	/* Not that many sectors in this track? */
 	if (sector_index>0)
 	{
-		free(track_data);
 		return FLOPPY_ERROR_SEEKERROR;
 	}
 
@@ -2445,7 +2436,6 @@ static floperr_t ti99_tdf_write_indexed_sector(floppy_image_legacy *floppy, int
 	/* There was no DAM. Image seems to be broken. */
 	if (i == tag->track_size)
 	{
-		free(track_data);
 		return FLOPPY_ERROR_SEEKERROR;
 	}
 
@@ -2469,9 +2459,6 @@ static floperr_t ti99_tdf_write_indexed_sector(floppy_image_legacy *floppy, int
 	crc_field[1] = (crc & 0xff);
 	floppy_image_write(floppy, crc_field, offset+SECTOR_SIZE, 2);
 
-	/* Free the temporary buffer */
-	free(track_data);
-
 	return FLOPPY_ERROR_SUCCESS;
 }
 
@@ -2481,12 +2468,11 @@ static floperr_t ti99_tdf_find_indexed_sector(floppy_image_legacy *floppy, int h
 	/* Read track, head */
 	int byte = 0;
 	struct ti99dsk_tag *tag = (ti99dsk_tag*)floppy_tag(floppy);
-	UINT8 *track_data;
+	dynamic_buffer track_data(tag->track_size);
 	int imgtrack = track;
 	int i;
 	floperr_t err;
 	floperr_t retval;
-	track_data = (UINT8*)malloc(tag->track_size);
 
 	if (use_80_track_drives && tag->tracks<=40)
 	{
@@ -2496,7 +2482,6 @@ static floperr_t ti99_tdf_find_indexed_sector(floppy_image_legacy *floppy, int h
 	err = ti99_tdf_read_track_internal(floppy, head, imgtrack, 0, track_data, tag->track_size);
 	if (err)
 	{
-		free(track_data);
 		return err;
 	}
 
@@ -2506,7 +2491,6 @@ static floperr_t ti99_tdf_find_indexed_sector(floppy_image_legacy *floppy, int h
 	{
 		if (determine_offset(tag->format, track_data, &tag->first_idam)==FLOPPY_ERROR_SEEKERROR)
 		{
-			free(track_data);
 			return FLOPPY_ERROR_SEEKERROR;
 		}
 	}
@@ -2572,7 +2556,6 @@ static floperr_t ti99_tdf_find_indexed_sector(floppy_image_legacy *floppy, int h
 			}
 		}
 	}
-	free(track_data);
 	return retval;
 }
 
@@ -2626,7 +2609,8 @@ static int ti99_tdf_guess_geometry(floppy_image_legacy *floppy, UINT64 size,
 {
 	int idamcnt, state, track, head, i, totalseclen = 0, format = 0, byte, tracklength, trackadd = 0;
 	int first_idam = 0;
-	UINT8 *track_data;
+	/* Allocate enough bytes to hold the longest supported track. */
+	dynamic_buffer track_data(13000);
 	/*int offset;*/
 
 	struct ti99dsk_geometry dummy_geometry;
@@ -2636,8 +2620,6 @@ static int ti99_tdf_guess_geometry(floppy_image_legacy *floppy, UINT64 size,
 	else
 		geometry = &dummy_geometry;
 
-	/* Allocate enough bytes to hold the longest supported track. */
-	track_data = (UINT8*)malloc(13000);
 	floppy_image_read(floppy, track_data, 0, 13000);
 
 	if (determine_offset(TI99_MFM, track_data, &first_idam)==FLOPPY_ERROR_SEEKERROR)
@@ -2652,7 +2634,6 @@ static int ti99_tdf_guess_geometry(floppy_image_legacy *floppy, UINT64 size,
 			// We only give a moderate vote in this case, so SDF
 			// make take it.
 
-			free(track_data);
 			if (size < 130120 || size > 2078720)
 			{
 				LOG_FORMATS("Unknown format size: %d\n", (int)size);
@@ -2794,7 +2775,6 @@ static int ti99_tdf_guess_geometry(floppy_image_legacy *floppy, UINT64 size,
 	{
 		/* error ... what now? */
 		LOG_FORMATS("Error when reading last track. Image broken.\n");
-		free(track_data);
 		return 50;
 	}
 	else
@@ -2824,11 +2804,9 @@ static int ti99_tdf_guess_geometry(floppy_image_legacy *floppy, UINT64 size,
 	if (geometry->tracksperside < 35 || geometry->tracksperside > 80)
 	{
 		LOG_FORMATS("Unsupported track count: %d\n", geometry->tracksperside);
-		free(track_data);
 		return 0;
 	}
 
-	free(track_data);
 	return 100;
 }
 
diff --git a/src/lib/formats/z80ne_dsk.c b/src/lib/formats/z80ne_dsk.c
index cc1d1901a31..0c408c987c2 100644
--- a/src/lib/formats/z80ne_dsk.c
+++ b/src/lib/formats/z80ne_dsk.c
@@ -10,6 +10,7 @@
 #include "z80ne_dsk.h"
 #include "basicdsk.h"
 #include "imageutl.h"
+#include "coretmpl.h"
 
 /* -----------------------------------------------------------------------
  * DMK file format
@@ -175,8 +176,8 @@ static floperr_t z80ne_dmk_format_track(floppy_image_legacy *floppy, int head, i
 	UINT8 *track_data;
 	void *track_data_v;
 	UINT32 max_track_size;
-	int *sector_map = NULL;
-	UINT8 *local_sector = NULL;
+	dynamic_array<int> sector_map;
+	dynamic_buffer local_sector;
 	int local_sector_size;
 	int sector_position;
 	int i;
@@ -206,13 +207,8 @@ static floperr_t z80ne_dmk_format_track(floppy_image_legacy *floppy, int head, i
 	track_data = (UINT8 *) track_data_v;
 
 	/* set up sector map */
-	sector_map = (int*)malloc(sectors * sizeof(*sector_map));
-	if (!sector_map)
-	{
-		err = FLOPPY_ERROR_OUTOFMEMORY;
-		goto done;
-	}
-	memset(sector_map, 0xFF, sectors * sizeof(*sector_map));
+	sector_map.resize(sectors);
+	sector_map.clear(0xFF);
 
 	physical_sector = 0;
 	for (logical_sector = 0; logical_sector < sectors; logical_sector++)
@@ -235,13 +231,8 @@ static floperr_t z80ne_dmk_format_track(floppy_image_legacy *floppy, int head, i
 							sector_length +
 							DMK_DATA_CRC_LEN +
 							DMK_DATA_GAP_LEN);
-	local_sector = (UINT8*)malloc(local_sector_size);
-	if (!local_sector)
-	{
-		err = FLOPPY_ERROR_OUTOFMEMORY;
-		goto done;
-	}
-	memset(local_sector, 0x00, local_sector_size);
+	local_sector.resize(local_sector_size);
+	local_sector.clear();
 
 	/* set up track table of contents */
 	physical_sector = 0;
@@ -326,11 +317,6 @@ static floperr_t z80ne_dmk_format_track(floppy_image_legacy *floppy, int head, i
 	memset(&track_data[track_position], 0xFF, max_track_size - track_position);
 
 done:
-	if (sector_map)
-		free(sector_map);
-	if (local_sector)
-		free(local_sector);
-
 	return err;
 }
 
@@ -392,7 +378,7 @@ static floperr_t z80ne_dmk_seek_sector_in_track(floppy_image_legacy *floppy, int
 	void *track_data_v;
 	size_t track_length;
 	size_t sec_len;
-	UINT8 *local_idam = NULL;
+	dynamic_buffer local_idam;
 	int local_idam_size;
 	UINT8 *sec_data;
 
@@ -406,13 +392,8 @@ static floperr_t z80ne_dmk_seek_sector_in_track(floppy_image_legacy *floppy, int
 							DMK_ID_GAP_LEN +
 							DMK_DAM_LEN +
 							DMK_DATA_GAP_LEN);
-	local_idam = (UINT8*)malloc(local_idam_size);
-	if (!local_idam)
-	{
-		err = FLOPPY_ERROR_OUTOFMEMORY;
-		goto done;
-	}
-	memset(local_idam, 0x00, local_idam_size);
+	local_idam.resize(local_idam_size);
+	local_idam.clear();
 
 	/* search for matching IDAM */
 	for (i = 0; i < DMK_TOC_LEN / 2; i++)
@@ -509,8 +490,6 @@ static floperr_t z80ne_dmk_seek_sector_in_track(floppy_image_legacy *floppy, int
 	if (sector_length)
 		*sector_length = sec_len;
 done:
-	if (local_idam)
-		free(local_idam);
 	return err;
 }
 
@@ -582,7 +561,7 @@ static floperr_t internal_z80ne_dmk_read_sector(floppy_image_legacy *floppy, int
 	UINT16 crc_on_disk;
 	UINT16 calculated_crc;
 	UINT8 *sector_data = NULL;
-	UINT8 *local_sector = NULL;
+	dynamic_buffer local_sector;
 	int local_sector_size;
 	int i;
 
@@ -593,13 +572,8 @@ static floperr_t internal_z80ne_dmk_read_sector(floppy_image_legacy *floppy, int
 
 	/* set up a local physical sector space (DAM + data + crc + GAP) */
 	local_sector_size = (DMK_DAM_LEN + sector_length + DMK_DATA_CRC_LEN + DMK_DATA_GAP_LEN);
-	local_sector = (UINT8*)malloc(local_sector_size);
-	if (!local_sector)
-	{
-		err = FLOPPY_ERROR_OUTOFMEMORY;
-		goto done;
-	}
-	memset(local_sector, 0x00, local_sector_size);
+	local_sector.resize(local_sector_size);
+	local_sector.clear();
 
 	/* get sector data */
 	/* create a local copy of sector data including DAM (for crc calculation) */
@@ -622,8 +596,6 @@ static floperr_t internal_z80ne_dmk_read_sector(floppy_image_legacy *floppy, int
 	memcpy(buffer, local_sector+1, MIN(sector_length, buflen));
 
 	done:
-	if (local_sector)
-		free(local_sector);
 	return err;
 }
 
@@ -635,7 +607,7 @@ static floperr_t internal_z80ne_dmk_write_sector(floppy_image_legacy *floppy, in
 	UINT32 sector_length;
 	UINT8 *sector_data;
 	UINT16 crc;
-	UINT8 *local_sector = NULL;
+	dynamic_buffer local_sector;
 	int local_sector_size;
 	int i;
 
@@ -646,13 +618,8 @@ static floperr_t internal_z80ne_dmk_write_sector(floppy_image_legacy *floppy, in
 
 	/* set up a local physical sector space */
 	local_sector_size = (DMK_DAM_LEN + sector_length + DMK_DATA_CRC_LEN + DMK_DATA_GAP_LEN);
-	local_sector = (UINT8*)malloc(local_sector_size);
-	if (!local_sector)
-	{
-		err = FLOPPY_ERROR_OUTOFMEMORY;
-		goto done;
-	}
-	memset(local_sector, 0x00, local_sector_size);
+	local_sector.resize(local_sector_size);
+	local_sector.clear();
 	if(!ddam)
 		local_sector[0] = 0xFB;
 	else
@@ -677,8 +644,6 @@ static floperr_t internal_z80ne_dmk_write_sector(floppy_image_legacy *floppy, in
 		sector_data[i*2] = sector_data[(i*2)+1] = local_sector[i];
 
 	done:
-	if (local_sector)
-		free(local_sector);
 	return err;
 }
 
diff --git a/src/mess/tools/imgtool/iflopimg.c b/src/mess/tools/imgtool/iflopimg.c
index 8933a44bcda..26a91ccf749 100644
--- a/src/mess/tools/imgtool/iflopimg.c
+++ b/src/mess/tools/imgtool/iflopimg.c
@@ -310,16 +310,11 @@ static imgtoolerr_t imgtool_floppy_transfer_sector_tofrom_stream(imgtool_image *
 {
 	floperr_t err;
 	floppy_image_legacy *floppy;
-	void *buffer = NULL;
+	dynamic_buffer buffer;
 
 	floppy = imgtool_floppy(img);
 
-	buffer = malloc(length);
-	if (!buffer)
-	{
-		err = FLOPPY_ERROR_OUTOFMEMORY;
-		goto done;
-	}
+	buffer.resize(length);
 
 	if (direction)
 	{
@@ -339,8 +334,6 @@ static imgtoolerr_t imgtool_floppy_transfer_sector_tofrom_stream(imgtool_image *
 	err = FLOPPY_ERROR_SUCCESS;
 
 done:
-	if (buffer)
-		free(buffer);
 	return imgtool_floppy_error(err);
 }
 
diff --git a/src/mess/tools/imgtool/imghd.c b/src/mess/tools/imgtool/imghd.c
index 1d66b05196c..65f404f531c 100644
--- a/src/mess/tools/imgtool/imghd.c
+++ b/src/mess/tools/imgtool/imghd.c
@@ -47,7 +47,7 @@ static imgtoolerr_t map_chd_error(chd_error chderr)
 imgtoolerr_t imghd_create(imgtool_stream *stream, UINT32 hunksize, UINT32 cylinders, UINT32 heads, UINT32 sectors, UINT32 seclen)
 {
 	imgtoolerr_t err = IMGTOOLERR_SUCCESS;
-	UINT8 *cache = NULL;
+	dynamic_buffer cache;
 	chd_file chd;
 	chd_error rc;
 	UINT64 logicalbytes;
@@ -101,13 +101,8 @@ imgtoolerr_t imghd_create(imgtool_stream *stream, UINT32 hunksize, UINT32 cylind
 	}
 
 	/* alloc and zero buffer */
-	cache = (UINT8*)malloc(hunksize);
-	if (!cache)
-	{
-		err = IMGTOOLERR_OUTOFMEMORY;
-		goto done;
-	}
-	memset(cache, '\0', hunksize);
+	cache.resize(hunksize);
+	cache.clear();
 
 	/* zero out every hunk */
 	totalhunks = (logicalbytes + hunksize - 1) / hunksize;
@@ -121,10 +116,7 @@ imgtoolerr_t imghd_create(imgtool_stream *stream, UINT32 hunksize, UINT32 cylind
 		}
 	}
 
-
 done:
-	if (cache)
-		free(cache);
 	return err;
 }
 
diff --git a/src/mess/tools/imgtool/main.c b/src/mess/tools/imgtool/main.c
index 056542c0646..3929a960336 100644
--- a/src/mess/tools/imgtool/main.c
+++ b/src/mess/tools/imgtool/main.c
@@ -625,7 +625,7 @@ static int cmd_readsector(const struct command *c, int argc, char *argv[])
 	imgtoolerr_t err;
 	imgtool_image *img;
 	imgtool_stream *stream = NULL;
-	void *buffer = NULL;
+	dynamic_buffer buffer;
 	UINT32 size, track, head, sector;
 
 	/* attempt to open image */
@@ -641,12 +641,7 @@ static int cmd_readsector(const struct command *c, int argc, char *argv[])
 	if (err)
 		goto done;
 
-	buffer = malloc(size);
-	if (!buffer)
-	{
-		err = IMGTOOLERR_OUTOFMEMORY;
-		goto done;
-	}
+	buffer.resize(size);
 
 	err = imgtool_image_read_sector(img, track, head, sector, buffer, size);
 	if (err)
@@ -663,8 +658,6 @@ static int cmd_readsector(const struct command *c, int argc, char *argv[])
 	stream_write(stream, buffer, size);
 
 done:
-	if (buffer)
-		free(buffer);
 	if (stream)
 		stream_close(stream);
 	if (err)
@@ -679,7 +672,7 @@ static int cmd_writesector(const struct command *c, int argc, char *argv[])
 	imgtoolerr_t err;
 	imgtool_image *img;
 	imgtool_stream *stream = NULL;
-	void *buffer = NULL;
+	dynamic_buffer buffer;
 	UINT32 size, track, head, sector;
 
 	/* attempt to open image */
@@ -700,12 +693,7 @@ static int cmd_writesector(const struct command *c, int argc, char *argv[])
 
 	size = (UINT32) stream_size(stream);
 
-	buffer = malloc(size);
-	if (!buffer)
-	{
-		err = (imgtoolerr_t)(IMGTOOLERR_OUTOFMEMORY);
-		goto done;
-	}
+	buffer.resize(size);
 
 	stream_read(stream, buffer, size);
 
@@ -714,8 +702,6 @@ static int cmd_writesector(const struct command *c, int argc, char *argv[])
 		goto done;
 
 done:
-	if (buffer)
-		free(buffer);
 	if (stream)
 		stream_close(stream);
 	if (err)
diff --git a/src/mess/tools/imgtool/modules/os9.c b/src/mess/tools/imgtool/modules/os9.c
index c0254d1a0c2..0e502d4d416 100644
--- a/src/mess/tools/imgtool/modules/os9.c
+++ b/src/mess/tools/imgtool/modules/os9.c
@@ -711,7 +711,7 @@ static imgtoolerr_t os9_diskimage_open(imgtool_image *image, imgtool_stream *str
 static imgtoolerr_t os9_diskimage_create(imgtool_image *img, imgtool_stream *stream, option_resolution *opts)
 {
 	imgtoolerr_t err;
-	UINT8 *header;
+	dynamic_buffer header;
 	UINT32 heads, tracks, sectors, sector_bytes, first_sector_id;
 	UINT32 cluster_size, owner_id;
 	UINT32 allocation_bitmap_bits, allocation_bitmap_lsns;
@@ -732,12 +732,7 @@ static imgtoolerr_t os9_diskimage_create(imgtool_image *img, imgtool_stream *str
 	first_sector_id = option_resolution_lookup_int(opts, 'F');
 	title = "";
 
-	header = (UINT8*)malloc(sector_bytes);
-	if (!header)
-	{
-		err = IMGTOOLERR_OUTOFMEMORY;
-		goto done;
-	}
+	header.resize(sector_bytes);
 
 	if (sector_bytes > 256)
 		sector_bytes = 256;
@@ -845,8 +840,6 @@ static imgtoolerr_t os9_diskimage_create(imgtool_image *img, imgtool_stream *str
 		goto done;
 
 done:
-	if (header)
-		free(header);
 	return err;
 }
 
@@ -1037,7 +1030,7 @@ static imgtoolerr_t os9_diskimage_writefile(imgtool_partition *partition, const
 	imgtool_image *image = imgtool_partition_image(partition);
 	struct os9_fileinfo file_info;
 	size_t write_size;
-	void *buf = NULL;
+	dynamic_buffer buf;
 	int i = -1;
 	UINT32 lsn = 0;
 	UINT32 count = 0;
@@ -1046,12 +1039,7 @@ static imgtoolerr_t os9_diskimage_writefile(imgtool_partition *partition, const
 
 	disk_info = os9_get_diskinfo(image);
 
-	buf = malloc(disk_info->sector_size);
-	if (!buf)
-	{
-		err = IMGTOOLERR_OUTOFMEMORY;
-		goto done;
-	}
+	buf.resize(disk_info->sector_size);
 
 	err = os9_lookup_path(image, path, CREATE_FILE, &file_info, NULL, NULL, NULL);
 	if (err)
@@ -1086,8 +1074,6 @@ static imgtoolerr_t os9_diskimage_writefile(imgtool_partition *partition, const
 	}
 
 done:
-	if (buf)
-		free(buf);
 	return err;
 }
 
diff --git a/src/mess/tools/imgtool/modules/psion.c b/src/mess/tools/imgtool/modules/psion.c
index 8ea7d193e7e..7b6e764efdd 100644
--- a/src/mess/tools/imgtool/modules/psion.c
+++ b/src/mess/tools/imgtool/modules/psion.c
@@ -286,15 +286,13 @@ UINT16 put_odb(imgtool_stream *instream, imgtool_stream *outstream, UINT8 file_i
 UINT16 put_ob3(imgtool_stream *instream, imgtool_stream *outstream)
 {
 	UINT16 size = stream_size(instream) - 6;
-	UINT8 *buffer = (UINT8*)malloc(size);
+	dynamic_buffer buffer(size);
 
 	stream_seek(instream, 6, SEEK_SET);
 	stream_read(instream, buffer, size);
 
 	stream_write(outstream, buffer, size);
 
-	free(buffer);
-
 	// end of pack
 	stream_fill(outstream, 0xff, 2);