Track and which letters are not used in the word

Makefile

@@ -21,4 +21,7 @@ clean:
 
 distclean: clean
 
-.PHONY: all clean distclean
+run: dosdl.com
+	dosbox dosdl.com
+
+.PHONY: all clean distclean run

README.md

@@ -19,7 +19,6 @@ Missing features
 - Ability to set the seed manually
 - Hard and extra hard modes
 - In-program help
-- Display of letters that have not been ruled out
 
 Word lists
 ----------

dosdl.asm

@@ -221,6 +221,8 @@ check_targets:
 
 word_not_found:
 	mov ah, 9
+	mov dx, space_dash_space_str
+	int 0x21
 	mov dx, not_found_str
 	int 0x21
 
@@ -277,7 +279,6 @@ find_exact_hits:
 
 find_wrong_places:
 	; Zero out first
-	mov di, wrong_places
 	mov cx, 5
 	xor al, al
 	rep stosb
@@ -334,6 +335,15 @@ find_wrong_places:
 			.not_found_in_wrong_places:
 			loop .count_wrong_places
 
+		; If not used in target at all, remove from list of possible letters
+		test bh, bh
+		jnz .used_in_target
+
+		xor dh, dh
+		mov di, dx
+		mov byte [alphabet + di - 'a'], ' '
+
+		.used_in_target:
 		; If in target more than in feedback → wrong place
 		cmp bh, bl ; target <= feedback
 		jbe .loop
@@ -374,6 +384,20 @@ print_feedback:
 
 		inc bp
 		loop .loop
+
+	mov ah, 9
+	mov dx, space_dash_space_str
+	int 0x21
+
+	mov cx, 26
+	mov si, alphabet
+	.alphabet_loop:
+		lodsb
+		mov dl, al
+		mov ah, 2
+		int 0x21
+		loop .alphabet_loop
+
 	call newline
 
 is_finished:
@@ -722,6 +746,7 @@ add32:
 %endif
 
 section .data
+alphabet db 'abcdefghijklmnopqrstuvwxyz'
 target times 5 db 0
 guess times 5 db 0
 
@@ -750,7 +775,8 @@ day db 0
 
 section .rodata
 
-not_found_str db ' - word not found$'
+space_dash_space_str db ' - $'
+not_found_str db 'word not found$'
 erase_word_str db '     $'
 word_was_str db 'The word was: $'
 correct_in_str db 'Correct in $'