diff --git a/basicmbr.h b/basicmbr.h
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+/* basicmbr.h -- MBR data structure definitions, types, and functions */
+
+/* This program is copyright (c) 2009 by Roderick W. Smith. It is distributed
+  under the terms of the GNU GPL version 2, as detailed in the COPYING file. */
+
+#include <stdint.h>
+#include <sys/types.h>
+#include "partnotes.h"
+#include "diskio.h"
+
+#ifndef __BASICMBRSTRUCTS
+#define __BASICMBRSTRUCTS
+
+#define MBR_SIGNATURE UINT16_C(0xAA55)
+#define MAX_HEADS 255        /* numbered 0 - 254 */
+#define MAX_SECSPERTRACK 63  /* numbered 1 - 63 */
+#define MAX_CYLINDERS 1024   /* numbered 0 - 1023 */
+
+// Maximum number of MBR partitions
+#define MAX_MBR_PARTS 128
+
+using namespace std;
+
+class PartNotes;
+
+/****************************************
+ *                                      *
+ * MBRData class and related structures *
+ *                                      *
+ ****************************************/
+
+// Data for a single MBR partition record
+// Note that firstSector and lastSector are in CHS addressing, which
+// splits the bits up in a weird way.
+// On read or write of MBR entries, firstLBA is an absolute disk sector.
+// On read of logical entries, it's relative to the EBR record for that
+// partition. When writing EBR records, it's relative to the extended
+// partition's start.
+#pragma pack(1)
+struct MBRRecord {
+   uint8_t status;
+   uint8_t firstSector[3];
+   uint8_t partitionType;
+   uint8_t lastSector[3];
+   uint32_t firstLBA; // see above
+   uint32_t lengthLBA;
+}; // struct MBRRecord
+
+// A 512-byte data structure into which the MBR can be loaded in one
+// go. Also used when loading logical partitions.
+#pragma pack(1)
+struct TempMBR {
+   uint8_t code[440];
+   uint32_t diskSignature;
+   uint16_t nulls;
+   struct MBRRecord partitions[4];
+   uint16_t MBRSignature;
+}; // struct TempMBR
+
+// Possible states of the MBR
+enum MBRValidity {invalid, gpt, hybrid, mbr};
+
+// Full data in tweaked MBR format
+class BasicMBRData {
+protected:
+   uint8_t code[440];
+   uint32_t diskSignature;
+   uint16_t nulls;
+   // MAX_MBR_PARTS defaults to 128. This array holds both the primary and
+   // the logical partitions, to simplify data retrieval for GPT conversions.
+   struct MBRRecord partitions[MAX_MBR_PARTS];
+   uint16_t MBRSignature;
+
+   // Above are basic MBR data; now add more stuff....
+   uint32_t blockSize; // block size (usually 512)
+   uint64_t diskSize; // size in blocks
+   uint64_t numHeads; // number of heads, in CHS scheme
+   uint64_t numSecspTrack; // number of sectors per track, in CHS scheme
+   DiskIO* myDisk;
+   int canDeleteMyDisk;
+   string device;
+   MBRValidity state;
+   struct MBRRecord* GetPartition(int i); // Return primary or logical partition
+public:
+   BasicMBRData(void);
+   BasicMBRData(string deviceFilename);
+   ~BasicMBRData(void);
+   BasicMBRData & operator=(const BasicMBRData & orig);
+
+   // File I/O functions...
+   int ReadMBRData(const string & deviceFilename);
+   int ReadMBRData(DiskIO * theDisk, int checkBlockSize = 1);
+   // ReadLogicalPart() returns last partition # read to logicals[] array,
+   // or -1 if there was a problem....
+   int ReadLogicalPart(uint32_t extendedStart, uint32_t diskOffset,
+                       int partNum);
+   int WriteMBRData(void);
+   int WriteMBRData(DiskIO *theDisk);
+   int WriteMBRData(const string & deviceFilename);
+   int WriteMBRData(struct TempMBR & mbr, DiskIO *theDisk, uint64_t sector);
+   void SetDisk(DiskIO *theDisk) {myDisk = theDisk; canDeleteMyDisk = 0;}
+
+   // Display data for user...
+   void DisplayMBRData(int maxParts = 4);
+   void ShowState(void);
+
+   // Functions that set or get disk metadata (size, CHS geometry, etc.)
+   void SetDiskSize(uint64_t ds) {diskSize = ds;}
+   void SetBlockSize(uint32_t bs) {blockSize = bs;}
+   MBRValidity GetValidity(void) {return state;}
+   void SetHybrid(void) {state = hybrid;} // Set hybrid flag
+   void SetCHSGeom(uint32_t h, uint32_t s);
+   int LBAtoCHS(uint64_t lba, uint8_t * chs); // Convert LBA to CHS
+   int Verify(void);
+
+   // Functions to create, delete, or change partitions
+   // Pass EmptyMBR 1 to clear the boot loader code, 0 to leave it intact
+   void EmptyMBR(int clearBootloader = 1);
+   void EmptyBootloader(void);
+   void MakePart(int num, uint32_t startLBA, uint32_t lengthLBA, int type = 0x07,
+                 int bootable = 0);
+   int SetPartType(int num, int type);
+   int SetPartBootable(int num, int bootable = 1);
+   int MakeBiggestPart(int i, int type); // Make partition filling most space
+   void DeletePartition(int i);
+   void RecomputeCHS(int partNum);
+   int CreateLogicals(PartNotes * notes);
+
+   // Functions to find information on free space....
+   uint32_t FindFirstAvailable(uint32_t start = 1);
+   uint32_t FindLastInFree(uint32_t start);
+   uint32_t FindFirstInFree(uint32_t start);
+   int IsFree(uint32_t sector);
+
+   // Functions to extract data on specific partitions....
+   uint8_t GetStatus(int i);
+   uint8_t GetType(int i);
+   uint32_t GetFirstSector(int i);
+   uint32_t GetLength(int i);
+}; // struct BasicMBRData
+
+#endif