#define SEGMENT_TO_MCB(seg) ((PDOS_MCB)SEG_OFF_TO_PTR((seg), 0))
+#define FIRST_MCB_SEGMENT 0x1000
+#define USER_MEMORY_SIZE (0x9FFE - FIRST_MCB_SEGMENT)
+
+#define UMB_START_SEGMENT 0xC000
+#define UMB_END_SEGMENT 0xDFFF
+
+#define DOS_ALLOC_HIGH 0x40
+#define DOS_ALLOC_HIGH_LOW 0x80
+
enum DOS_ALLOC_STRATEGY
{
DOS_ALLOC_FIRST_FIT,