diff --git a/src/floppy/fdc_monster.c b/src/floppy/fdc_monster.c
index 2feafdf07..d2dedb5c0 100644
--- a/src/floppy/fdc_monster.c
+++ b/src/floppy/fdc_monster.c
@@ -26,6 +26,8 @@
 #include <86box/device.h>
 #include <86box/io.h>
 #include <86box/mem.h>
+#include <86box/timer.h>
+#include <86box/nvr.h>
 #include <86box/rom.h>
 #include <86box/machine.h>
 #include <86box/timer.h>
@@ -41,7 +43,7 @@ typedef struct monster_fdc_t {
     rom_t  bios_rom;
     fdc_t *fdc_pri;
     fdc_t *fdc_sec;
-    char  *nvr_path;
+    char   nvr_path[64];
 } monster_fdc_t;
 
 static void
@@ -100,10 +102,12 @@ monster_fdc_close(void *priv)
 {
     monster_fdc_t *dev = (monster_fdc_t *) priv;
 
-    FILE *f = fopen(dev->nvr_path, "wb");
-    if (f != NULL) {
-        fwrite(dev->bios_rom.rom, 1, 0x2000, f);
-        fclose(f);
+    if (dev->nvr_path[0] != 0x00) {
+        FILE *f = nvr_fopen(dev->nvr_path, "wb");
+        if (f != NULL) {
+            fwrite(dev->bios_rom.rom, 1, 0x2000, f);
+            fclose(f);
+        }
     }
 
     free(dev);
@@ -114,8 +118,7 @@ monster_fdc_init(UNUSED(const device_t *info))
 {
     monster_fdc_t *dev;
 
-    dev = (monster_fdc_t *) malloc(sizeof(monster_fdc_t));
-    memset(dev, 0, sizeof(monster_fdc_t));
+    dev = (monster_fdc_t *) calloc(1, sizeof(monster_fdc_t));
 
 #if 0
     uint8_t sec_irq = device_get_config_int("sec_irq");
@@ -140,15 +143,13 @@ monster_fdc_init(UNUSED(const device_t *info))
     uint8_t rom_writes_enabled = device_get_config_int("rom_writes_enabled");
     if (rom_writes_enabled) {
         mem_mapping_set_write_handler(&dev->bios_rom.mapping, rom_write, rom_writew, rom_writel);
-        dev->nvr_path     = "monster_fdc_0.nvr";
-        dev->nvr_path[12] = device_get_instance() + 0x30;
-        FILE *f = fopen(dev->nvr_path, "rb");
+        sprintf(dev->nvr_path, "monster_fdc_%i.nvr", device_get_instance());
+        FILE *f = nvr_fopen(dev->nvr_path, "rb");
         if (f != NULL) {
             fread(dev->bios_rom.rom, 1, 0x2000, f);
             fclose(f);
         }
-    } else
-        dev->nvr_path = NULL;
+    }
 
     return dev;
 }
diff --git a/src/include/86box/scsi_x54x.h b/src/include/86box/scsi_x54x.h
index 0f1874302..8d5964de5 100644
--- a/src/include/86box/scsi_x54x.h
+++ b/src/include/86box/scsi_x54x.h
@@ -476,7 +476,8 @@ typedef struct x54x_t {
     /* 8 bytes */
     char *bios_path;  /* path to BIOS image file */
     char *mcode_path; /* path to microcode image file, needed by the AHA-1542CP */
-    char *nvr_path;   /* path to NVR image file */
+
+    char nvr_path[64]; /* path to NVR image file */
 
     /* 56 bytes */
     /* Pointer to a structure of vendor-specific data that only the vendor-specific code can understand */
diff --git a/src/scsi/scsi_aha154x.c b/src/scsi/scsi_aha154x.c
index c811c2c87..7d9f1ba24 100644
--- a/src/scsi/scsi_aha154x.c
+++ b/src/scsi/scsi_aha154x.c
@@ -921,7 +921,7 @@ aha_setnvr(x54x_t *dev)
     FILE *fp;
 
     /* Only if this device has an EEPROM. */
-    if (dev->nvr_path == NULL)
+    if (dev->nvr_path[0] == 0x00)
         return;
 
     /* Allocate and initialize the EEPROM. */
@@ -1043,8 +1043,7 @@ aha_init(const device_t *info)
         case AHA_154xC:
             strcpy(dev->name, "AHA-154xC");
             dev->bios_path       = "roms/scsi/adaptec/aha1542c102.bin";
-            dev->nvr_path        = "aha1542c_0.nvr";
-            dev->nvr_path[9]     = device_get_instance() + 0x30;
+            sprintf(dev->nvr_path, "aha1542c_%i.nvr", device_get_instance());
             dev->fw_rev          = "D001";
             dev->rom_shram       = 0x3F80;          /* shadow RAM address base */
             dev->rom_shramsz     = 128;             /* size of shadow RAM */
@@ -1060,8 +1059,7 @@ aha_init(const device_t *info)
         case AHA_154xCF:
             strcpy(dev->name, "AHA-154xCF");
             dev->bios_path   = "roms/scsi/adaptec/aha1542cf211.bin";
-            dev->nvr_path    = "aha1542cf_0.nvr";
-            dev->nvr_path[10] = device_get_instance() + 0x30;
+            sprintf(dev->nvr_path, "aha1542cf_%i.nvr", device_get_instance());
             dev->fw_rev      = "E001";
             dev->rom_shram   = 0x3F80; /* shadow RAM address base */
             dev->rom_shramsz = 128;    /* size of shadow RAM */
@@ -1082,8 +1080,7 @@ aha_init(const device_t *info)
             bios_rev         = (char *) device_get_config_bios("bios_rev");
             dev->bios_path   = (char *) device_get_bios_file(info, bios_rev, 0);
             dev->mcode_path  = (char *) device_get_bios_file(info, bios_rev, 1);
-            dev->nvr_path    = "aha1542cp_0.nvr";
-            dev->nvr_path[10] = device_get_instance() + 0x30;
+            sprintf(dev->nvr_path, "aha1542cp_%i.nvr", device_get_instance());
             dev->fw_rev      = aha1542cp_rev;
             dev->rom_shram   = 0x3F80; /* shadow RAM address base */
             dev->rom_shramsz = 128;    /* size of shadow RAM */
diff --git a/src/scsi/scsi_ncr53c8xx.c b/src/scsi/scsi_ncr53c8xx.c
index 1fd9fcdba..1395c2f6f 100644
--- a/src/scsi/scsi_ncr53c8xx.c
+++ b/src/scsi/scsi_ncr53c8xx.c
@@ -205,7 +205,7 @@ typedef enum {
 } scsi_state_t;
 
 typedef struct ncr53c8xx_t {
-    char         *nvr_path;
+    char          nvr_path[64];
     uint8_t       pci_slot;
     uint8_t       chip, wide;
     int           has_bios;
@@ -2571,39 +2571,37 @@ ncr53c8xx_init(const device_t *info)
 
     switch (dev->chip) {
         case CHIP_810:
-            dev->nvr_path = "ncr53c810_0.nvr";
+            sprintf(dev->nvr_path, "ncr53c810_%i.nvr", device_get_instance());
             dev->wide     = 0;
             break;
         case CHIP_815:
             dev->chip_rev = 0x04;
-            dev->nvr_path = "ncr53c815_0.nvr";
+            sprintf(dev->nvr_path, "ncr53c815_%i.nvr", device_get_instance());
             dev->wide     = 0;
             break;
         case CHIP_820:
-            dev->nvr_path = "ncr53c820_0.nvr";
+            sprintf(dev->nvr_path, "ncr53c820_%i.nvr", device_get_instance());
             dev->wide     = 1;
             break;
         case CHIP_825:
             dev->chip_rev = 0x26;
-            dev->nvr_path = "ncr53c825_0.nvr";
+            sprintf(dev->nvr_path, "ncr53c825a_%i.nvr", device_get_instance());
             dev->wide     = 1;
             break;
         case CHIP_860:
             scsi_bus_set_speed(dev->bus, 20000000.0);
             dev->chip_rev = 0x04;
-            dev->nvr_path = "ncr53c860_0.nvr";
+            sprintf(dev->nvr_path, "ncr53c860_%i.nvr", device_get_instance());
             dev->wide     = 1;
             break;
         case CHIP_875:
             scsi_bus_set_speed(dev->bus, 40000000.0);
             dev->chip_rev = 0x04;
-            dev->nvr_path = "ncr53c875_0.nvr";
+            sprintf(dev->nvr_path, "ncr53c875_%i.nvr", device_get_instance());
             dev->wide     = 1;
             break;
     }
 
-    dev->nvr_path[10] = device_get_instance() + 0x30;
-
     ncr53c8xx_pci_bar[0].addr_regs[0] = 1;
     ncr53c8xx_pci_bar[1].addr_regs[0] = 0;
     ncr53c8xx_pci_regs[0x04]          = 3;
diff --git a/src/scsi/scsi_pcscsi.c b/src/scsi/scsi_pcscsi.c
index 48b2d52fa..a714ada96 100644
--- a/src/scsi/scsi_pcscsi.c
+++ b/src/scsi/scsi_pcscsi.c
@@ -152,7 +152,7 @@
 typedef struct esp_t {
     mem_mapping_t mmio_mapping;
     mem_mapping_t ram_mapping;
-    char         *nvr_path;
+    char          nvr_path[64];
     uint8_t       pci_slot;
     int           has_bios;
     int           BIOSBase;
@@ -1856,8 +1856,7 @@ dc390_init(UNUSED(const device_t *info))
     if (dev->has_bios)
         esp_bios_disable(dev);
 
-    dev->nvr_path    = "dc390_0.nvr";
-    dev->nvr_path[6] = device_get_instance() + 0x30;
+    sprintf(dev->nvr_path, "dc390_%i.nvr", device_get_instance());
 
     /* Load the serial EEPROM. */
     dc390_load_eeprom(dev);