DOS wedge can now display directories

c64/kernal/iec/iec_cmd_close.s

@@ -7,12 +7,8 @@
 
 iec_cmd_close:
 
-	jsr iec_tx_flush
-
-	;; Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
-	;; allowed channels are 0-15; report error if out of range
-	cmp #$10
-	bcc + 
+	jsr iec_check_channel_openclose
+	bcc +
 	jmp kernalerror_FILE_NOT_INPUT
 *
 	ora #$E0

c64/kernal/iec/iec_cmd_open.s

@@ -8,10 +8,8 @@
 
 iec_cmd_open: ; similar to TKSA, but without turnaround
 
-	;; Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
-	;; allowed channels are 0-15; report error if out of range
-	cmp #$10
-	bcc + 
+	jsr iec_check_channel_openclose
+	bcc +
 	jmp kernalerror_FILE_NOT_INPUT
 *
 	ora #$F0
@@ -27,3 +25,18 @@ common_open_close_unlsn_second: ; common part of several commands
 *
 	rts
 
+iec_check_channel_openclose:
+	;; Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
+	;; allowed channels are 0-15; report error if out of range
+	cmp #$10
+	bcc + 
+	;; Workaround to allow reading executable files and disk directory
+	;; using OPEN routine - see https://www.pagetable.com/?p=273 for
+	;; example usage
+	cmp #$60
+	beq +
+	sec ; mark unsuitable channel number
+	rts
+*
+	clc ; mark suitable channel number
+	rts

c64/kernal/open.s

@@ -78,9 +78,11 @@ open_iec:
 	bcc +
 	jmp kernalerror_DEVICE_NOT_FOUND ; XXX find a better error message for wrong channel (create new one?)
 *
+
+	;; We need our helpers to get to filenames under ROMs or IO area
+	jsr install_ram_routines
+
 	;; Send command ('file name')
 	jsr lvs_send_file_name
 
 	jmp open_done_success
-
-