work towards directory reading in CBDOS

src/dos_m65/dev_ramdisk/dev_rd_cmd_open.s

@@ -9,3 +9,9 @@ dev_rd_cmd_OPEN:
 	; XXX provide implementation
 
 	jmp dos_EXIT_SEC
+
+dev_rd_cmd_OPEN_EOI:
+
+	; XXX provide implementation
+
+	jmp dos_EXIT

src/dos_m65/dev_ramdisk/dev_rd_cmd_read.s

@@ -0,0 +1,12 @@
+
+;
+; Read more data into the buffer
+;
+
+
+dev_rd_cmd_READ:
+
+	; XXX provide implementation
+
+	sec ; mark EOI
+	rts

src/dos_m65/dev_ramdisk/dev_rd_init.s

@@ -12,6 +12,10 @@ dev_rd_init:
 	stx RD_STATUS_IDX
 	stx RD_CMDFN_IDX
 	stx RD_MODE
+	stx RD_ACPTR_LEN+0
+	stx RD_ACPTR_LEN+1
+	stx RD_ACPTR_PTR+0
+	stx RD_ACPTR_PTR+1
 	dex
 @1:
 	inx