diff --git a/constants/SP2000.inc b/constants/SP2000.inc
index 2cd2617..4dd91c4 100644
--- a/constants/SP2000.inc
+++ b/constants/SP2000.inc
@@ -638,10 +638,10 @@ SYS_PAGE		EQU #FE
 .RAMD_FAT               EQU #C200                                       ; RAM Table
 .MS_BPB                 EQU #C400                                       ; буфер BPB
 ;	IDENTIFY ATA buffer
-.HD_IDF_ADR             EQU #C600                                       ; !FIXIT структурой сделать!!!
+.HD_IDF_ADR             EQU #C600                                       ; !FIXIT структурой сделать!!!--
 .HD_IDF_ADR.sec_cyl     EQU .HD_IDF_ADR+4
-.HD_IDF_ADR.heads       EQU .HD_IDF_ADR+6
-.HD_IDF_ADR.sectors     EQU .HD_IDF_ADR+12
+.HD_IDF_ADR.heads       EQU .HD_IDF_ADR+6				; Number of heads
+.HD_IDF_ADR.sectors     EQU .HD_IDF_ADR+12				; Number of sectors per track 
 ;
 .MS_DIR                 EQU #C800                                       ; буфер DIR sector
 .MS_FAT                 EQU #CC00                                       ; буфер FAT sector