more work on SD card support

src/dos_m65/,aliases_dos.s

@@ -2,17 +2,41 @@
 ; Memory locations for the DOS
 ;
 
+; NOTES:
+; - DOS zeropage is mirrored at $8000
+; - starting from $8000, 16KB RAM is available (starting from $10000 in C65 address space)
+; - additional 16KB RAM is reserved for DOS too ($14000-$17FFF), and can be banked-in if needed
+
+
+
 	;
 	; Page 0
 	;
 
-	!addr MAGICSTR     = $00 ; magic string; if not matching, DOS considered non-functional
+	!addr MAGICSTR         = $00 ; magic string; if not matching, DOS considered non-functional
 
-	!addr UNIT_SDCARD  = $05
-	!addr UNIT_FLOPPY  = $06
-	!addr UNIT_RAMDISK = $07
+	; General DOS configuration
 
-	; NOTES:
-	; - DOS zeropage is mirrored at $8000
-	; - starting from $8000, 16KB RAM is available (starting from $10000 in C65 address space)
-	; - additional 16KB RAM is reserved for DOS too ($14000-$17FFF), and can be banked-in if needed
+	!addr UNIT_SDCARD      = $05
+	!addr UNIT_FLOPPY      = $06
+	!addr UNIT_RAMDISK     = $07
+
+	; SD/SDHC card variables
+
+	!addr CARD_INIT_DONE   = $08 ; $80 - init done, $00 - init not done
+    !addr CARD_IS_SDHC     = $09 ; $00 = SD, $80 = SDHC
+    !addr CARD_SIZE        = $0A ; 4 bytes
+    !addr CARD_SECNUM      = $0E ; 4 bytes - sector number
+
+    !addr CARD_TMP_STEP    = $12 ; 4 bytes
+    !addr CARD_TMP_RETRIES = $16 ; 1 byte
+
+    !addr CARD_BUFPNT      = $FC ; 4 bytes - pointer to hardware sector buffer  XXX replace copy routines with DMAgic
+
+
+
+	;
+	; High memory
+	;
+
+	!addr CARD_BUF     = $8100 ; 512 bytes, up to $82FF - buffer for reading/writing data