diff --git a/src/ata.c b/src/ata.c
index 2996728..20d360a 100644
--- a/src/ata.c
+++ b/src/ata.c
@@ -18,13 +18,6 @@
 #include "disk.h" // struct ata_s
 #include "atabits.h" // ATA_CB_STAT
 
-#define TIMEOUT 0
-#define BSY 1
-#define NOT_BSY 2
-#define NOT_BSY_DRQ 3
-#define NOT_BSY_NOT_DRQ 4
-#define NOT_BSY_RDY 5
-
 #define IDE_SECTOR_SIZE 512
 #define CDROM_SECTOR_SIZE 2048
 
@@ -125,7 +118,7 @@
 
     // On a user-reset request, wait for RDY if it is an ATA device.
     u8 type=GET_GLOBAL(ATA.devices[driveid].type);
-    if (type == ATA_TYPE_ATA)
+    if (type == DTYPE_ATA)
         status = await_rdy(iobase1);
 
 done:
@@ -135,6 +128,30 @@
     dprintf(6, "ata_reset exit status=%x\n", status);
 }
 
+static int
+isready(int driveid)
+{
+    // Read the status from controller
+    u8 channel = driveid / 2;
+    u16 iobase1 = GET_GLOBAL(ATA.channels[channel].iobase1);
+    u8 status = inb(iobase1 + ATA_CB_STAT);
+    return (status & ( ATA_CB_STAT_BSY | ATA_CB_STAT_RDY )) == ATA_CB_STAT_RDY;
+}
+
+static int
+process_ata_misc_op(struct disk_op_s *op)
+{
+    switch (op->command) {
+    default:
+        return 0;
+    case CMD_RESET:
+        ata_reset(op->driveid);
+        return 0;
+    case CMD_ISREADY:
+        return isready(op->driveid);
+    }
+}
+
 
 /****************************************************************
  * ATA send command
@@ -325,15 +342,12 @@
 process_ata_op(struct disk_op_s *op)
 {
     switch (op->command) {
-    default:
-        return 0;
-    case CMD_RESET:
-        ata_reset(op->driveid);
-        return 0;
     case CMD_READ:
         return ata_cmd_data(op, 0, ATA_CMD_READ_SECTORS);
     case CMD_WRITE:
         return ata_cmd_data(op, 1, ATA_CMD_WRITE_SECTORS);
+    default:
+        return process_ata_misc_op(op);
     }
 }
 
@@ -412,13 +426,10 @@
 process_atapi_op(struct disk_op_s *op)
 {
     switch (op->command) {
-    default:
-        return 0;
-    case CMD_RESET:
-        ata_reset(op->driveid);
-        return 0;
     case CMD_READ:
         return cdrom_read(op);
+    default:
+        return process_ata_misc_op(op);
     }
 }
 
@@ -463,10 +474,10 @@
     u16 spt = GET_GLOBAL(ATA.devices[driveid].pchs.spt);
 
     if (cylinders <= 1024 && heads <= 16 && spt <= 63)
-        return ATA_TRANSLATION_NONE;
+        return TRANSLATION_NONE;
     if (cylinders * heads <= 131072)
-        return ATA_TRANSLATION_LARGE;
-    return ATA_TRANSLATION_LBA;
+        return TRANSLATION_LARGE;
+    return TRANSLATION_LBA;
 }
 
 static void
@@ -485,10 +496,10 @@
     dprintf(1, "ata%d-%d: PCHS=%u/%d/%d translation="
             , channel, slave, cylinders, heads, spt);
     switch (translation) {
-    case ATA_TRANSLATION_NONE:
+    case TRANSLATION_NONE:
         dprintf(1, "none");
         break;
-    case ATA_TRANSLATION_LBA:
+    case TRANSLATION_LBA:
         dprintf(1, "lba");
         spt = 63;
         if (sectors > 63*255*1024) {
@@ -510,7 +521,7 @@
             heads = 16;
         cylinders = sect / heads;
         break;
-    case ATA_TRANSLATION_RECHS:
+    case TRANSLATION_RECHS:
         dprintf(1, "r-echs");
         // Take care not to overflow
         if (heads==16) {
@@ -520,8 +531,8 @@
             cylinders = (u16)((u32)(cylinders)*16/15);
         }
         // then go through the large bitshift process
-    case ATA_TRANSLATION_LARGE:
-        if (translation == ATA_TRANSLATION_LARGE)
+    case TRANSLATION_LARGE:
+        if (translation == TRANSLATION_LARGE)
             dprintf(1, "large");
         while (cylinders > 1024) {
             cylinders >>= 1;
@@ -598,23 +609,24 @@
 
     // Success - setup as ATAPI.
     extract_identify(driveid, buffer);
-    SET_GLOBAL(ATA.devices[driveid].type, ATA_TYPE_ATAPI);
-    SET_GLOBAL(ATA.devices[driveid].device, (buffer[0] >> 8) & 0x1f);
+    SET_GLOBAL(ATA.devices[driveid].type, DTYPE_ATAPI);
     SET_GLOBAL(ATA.devices[driveid].blksize, CDROM_SECTOR_SIZE);
     SET_GLOBAL(ATA.devices[driveid].sectors, (u64)-1);
-
-    // fill cdidmap
-    u8 cdcount = GET_GLOBAL(ATA.cdcount);
-    SET_GLOBAL(ATA.idmap[1][cdcount], driveid);
-    SET_GLOBAL(ATA.cdcount, cdcount+1);
+    u8 iscd = ((buffer[0] >> 8) & 0x1f) == 0x05;
 
     // Report drive info to user.
     u8 channel = driveid / 2;
     u8 slave = driveid % 2;
     printf("ata%d-%d: %s ATAPI-%d %s\n", channel, slave
            , ATA.devices[driveid].model, ATA.devices[driveid].version
-           , (ATA.devices[driveid].device == ATA_DEVICE_CDROM
-              ? "CD-Rom/DVD-Rom" : "Device"));
+           , (iscd ? "CD-Rom/DVD-Rom" : "Device"));
+
+    // fill cdidmap
+    if (iscd) {
+        u8 cdcount = GET_GLOBAL(ATA.cdcount);
+        SET_GLOBAL(ATA.idmap[1][cdcount], driveid);
+        SET_GLOBAL(ATA.cdcount, cdcount+1);
+    }
 
     return 0;
 }
@@ -636,8 +648,7 @@
 
     // Success - setup as ATA.
     extract_identify(driveid, buffer);
-    SET_GLOBAL(ATA.devices[driveid].type, ATA_TYPE_ATA);
-    SET_GLOBAL(ATA.devices[driveid].device, ATA_DEVICE_HD);
+    SET_GLOBAL(ATA.devices[driveid].type, DTYPE_ATA);
     SET_GLOBAL(ATA.devices[driveid].blksize, IDE_SECTOR_SIZE);
 
     SET_GLOBAL(ATA.devices[driveid].pchs.cylinders, buffer[1]);
diff --git a/src/atabits.h b/src/atabits.h
index 688b70b..8495107 100644
--- a/src/atabits.h
+++ b/src/atabits.h
@@ -105,31 +105,3 @@
 #define ATA_CMD_WRITE_MULTIPLE               0xC5
 #define ATA_CMD_WRITE_SECTORS                0x30
 #define ATA_CMD_WRITE_VERIFY                 0x3C
-
-#define ATA_IFACE_NONE    0x00
-#define ATA_IFACE_ISA     0x00
-#define ATA_IFACE_PCI     0x01
-
-#define ATA_TYPE_NONE     0x00
-#define ATA_TYPE_ATA      0x02
-#define ATA_TYPE_ATAPI    0x03
-
-#define ATA_DEVICE_NONE  0x00
-#define ATA_DEVICE_HD    0xFF
-#define ATA_DEVICE_CDROM 0x05
-
-#define ATA_MODE_NONE    0x00
-#define ATA_MODE_PIO16   0x00
-#define ATA_MODE_PIO32   0x01
-#define ATA_MODE_ISADMA  0x02
-#define ATA_MODE_PCIDMA  0x03
-#define ATA_MODE_USEIRQ  0x10
-
-#define ATA_TRANSLATION_NONE  0
-#define ATA_TRANSLATION_LBA   1
-#define ATA_TRANSLATION_LARGE 2
-#define ATA_TRANSLATION_RECHS 3
-
-#define ATA_DATA_NO      0x00
-#define ATA_DATA_IN      0x01
-#define ATA_DATA_OUT     0x02
diff --git a/src/cdrom.c b/src/cdrom.c
index 2cb3f0f..c62829a 100644
--- a/src/cdrom.c
+++ b/src/cdrom.c
@@ -9,7 +9,7 @@
 #include "util.h" // memset
 #include "bregs.h" // struct bregs
 #include "biosvar.h" // GET_EBDA
-#include "atabits.h" // ATA_TYPE_ATAPI
+#include "atabits.h" // ATA_CMD_REQUEST_SENSE
 
 
 /****************************************************************
@@ -404,8 +404,6 @@
     if (cdid >= ATA.cdcount)
         return 1;
     int driveid = GET_GLOBAL(ATA.idmap[1][cdid]);
-    if (GET_GLOBAL(ATA.devices[driveid].device) != ATA_DEVICE_CDROM)
-        return 2;
 
     int ret = atapi_is_ready(driveid);
     if (ret)
diff --git a/src/disk.c b/src/disk.c
index d012af7..4ace85c 100644
--- a/src/disk.c
+++ b/src/disk.c
@@ -12,7 +12,7 @@
 #include "pic.h" // eoi_pic2
 #include "bregs.h" // struct bregs
 #include "pci.h" // pci_bdf_to_bus
-#include "atabits.h" // ATA_CB_STAT
+#include "atabits.h" // ATA_CB_DC
 
 
 /****************************************************************
@@ -57,9 +57,9 @@
 
     int status = 0;
     u8 type = GET_GLOBAL(ATA.devices[dop.driveid].type);
-    if (type == ATA_TYPE_ATA)
+    if (type == DTYPE_ATA)
         status = process_ata_op(&dop);
-    else if (type == ATA_TYPE_ATAPI)
+    else if (type == DTYPE_ATAPI)
         status = process_atapi_op(&dop);
 
     irq_disable();
@@ -343,12 +343,14 @@
 {
     // should look at 40:8E also???
 
-    // Read the status from controller
-    u8 status = inb(GET_GLOBAL(ATA.channels[device/2].iobase1) + ATA_CB_STAT);
-    if ( (status & ( ATA_CB_STAT_BSY | ATA_CB_STAT_RDY )) == ATA_CB_STAT_RDY )
-        disk_ret(regs, DISK_RET_SUCCESS);
-    else
+    struct disk_op_s dop;
+    dop.driveid = device;
+    dop.command = CMD_ISREADY;
+    int status = send_disk_op(&dop);
+    if (status)
         disk_ret(regs, DISK_RET_ENOTREADY);
+    else
+        disk_ret(regs, DISK_RET_SUCCESS);
 }
 
 // recalibrate
@@ -462,7 +464,7 @@
             , size, type, npc, nph, npspt, (u32)lba, blksize);
 
     SET_INT13DPT(regs, size, 26);
-    if (type == ATA_TYPE_ATA) {
+    if (type == DTYPE_ATA) {
         if (lba > (u64)npspt*nph*0x3fff) {
             SET_INT13DPT(regs, infos, 0x00); // geometry is invalid
             SET_INT13DPT(regs, cylinders, 0x3fff);
@@ -506,13 +508,13 @@
     u8 irq = GET_GLOBAL(ATA.channels[channel].irq);
 
     u16 options = 0;
-    if (type == ATA_TYPE_ATA) {
+    if (type == DTYPE_ATA) {
         u8 translation = GET_GLOBAL(ATA.devices[device].translation);
-        if (translation != ATA_TRANSLATION_NONE) {
+        if (translation != TRANSLATION_NONE) {
             options |= 1<<3; // CHS translation
-            if (translation == ATA_TRANSLATION_LBA)
+            if (translation == TRANSLATION_LBA)
                 options |= 1<<9;
-            if (translation == ATA_TRANSLATION_RECHS)
+            if (translation == TRANSLATION_RECHS)
                 options |= 3<<9;
         }
     } else {
diff --git a/src/disk.h b/src/disk.h
index 441eca6..260affa 100644
--- a/src/disk.h
+++ b/src/disk.h
@@ -149,11 +149,12 @@
     u8 command;
 };
 
-#define CMD_RESET  0
-#define CMD_READ   2
-#define CMD_WRITE  3
-#define CMD_VERIFY 4
-#define CMD_SEEK   7
+#define CMD_RESET   0x00
+#define CMD_READ    0x02
+#define CMD_WRITE   0x03
+#define CMD_VERIFY  0x04
+#define CMD_SEEK    0x07
+#define CMD_ISREADY 0x10
 
 
 /****************************************************************
@@ -175,7 +176,6 @@
 
 struct ata_device_s {
     u8  type;         // Detected type of ata (ata/atapi/none/unknown)
-    u8  device;       // Detected type of attached devices (hd/cd/none)
     u8  removable;    // Removable device flag
     u16 blksize;      // block size
     u8  version;      // ATA/ATAPI version
@@ -189,12 +189,21 @@
     u64 sectors;      // Total sectors count
 };
 
+#define DTYPE_NONE     0x00
+#define DTYPE_ATA      0x02
+#define DTYPE_ATAPI    0x03
+
+#define TRANSLATION_NONE  0
+#define TRANSLATION_LBA   1
+#define TRANSLATION_LARGE 2
+#define TRANSLATION_RECHS 3
+
 struct ata_s {
     // ATA channels info
     struct ata_channel_s channels[CONFIG_MAX_ATA_INTERFACES];
 
     // ATA devices info
-    struct ata_device_s  devices[CONFIG_MAX_ATA_DEVICES];
+    struct ata_device_s devices[CONFIG_MAX_ATA_DEVICES];
     //
     // map between bios hd/cd id and ata channels
     u8 cdcount;