DOS Wedge now prints our empty SD card directory

src/dos_m65/assets/dos_parts_dir.s

@@ -20,7 +20,7 @@ dir_hdr_sd:                  ; 32 bytes - header
 	!byte $01, $01           ; link to the next line - dummy, will be regenerated by BASIC
 	!byte $00, $00           ; line number 0
 	!byte $12, $22           ; reverse mode, quote
-	!pet "SD CARD         "  ; space for disk/directory name
+	!pet "sd card         "  ; space for disk/directory name
     !byte $22, $20           ; quote, space
 	!pet "fat32"             ; filesystem
 	!byte $00                ; end of the line

src/dos_m65/dev_sdcard/dev_sd_cmd_read.s

@@ -6,7 +6,27 @@
 
 dev_sd_cmd_READ:
 
-	; XXX provide implementation
+	; XXX provide implementation for regular files
+
+	lda SD_DIR_PHASE
+	cmp #$01
+	beq dev_sd_cmd_READ_dir_blocksfree
 
 	sec ; mark EOI
 	rts
+
+
+dev_sd_cmd_READ_dir_blocksfree:
+
+	lda #$13
+	sta SD_ACPTR_LEN+0
+	lda #$00
+	sta SD_ACPTR_LEN+1
+
+	lda #<dir_end
+	sta SD_ACPTR_PTR+0
+	lda #>dir_end
+	sta SD_ACPTR_PTR+1
+
+	clc
+	rts

src/dos_m65/msg_acptr.s

@@ -38,6 +38,7 @@ msg_ACPTR_read_SD:
 
 	jsr SD_ACPTR_helper
 	sta TBTCNT
+	sta REG_A
 
 	; Increment pointer, decrement length
 
@@ -77,6 +78,7 @@ msg_ACPTR_fail_no_data:
 	; XXX What should be the reaction when trying to read and no data is present?
 
 	sta TBTCNT
+	sta REG_A
 	bra msg_ACPTR_EOI
 
 msg_ACPTR_status: