DOS Wedge now prints our empty SD card directory

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