some work on CAPS LOCK support

src/kernal/keyboard_m65/mega65_scnkey.s

@@ -132,16 +132,21 @@ m65_scnkey_next_1:
 	;
 
 	; XXX add proper implementation
-	ldx M65_KB_PRESSED+0
+	ldy M65_KB_PRESSED+0
+
+	; FALLTROUGH
+
+m65_scnkey_got_key: ; .Y should now contain the key offset in matrix pointed by KEYTAB
 
 	;
 	; Convert the key coordinates to key code
 	;
 
-	; XXX add proper implementation
-	ldy __kb_matrix_normal, x
+	ldy __kb_matrix_normal, x ; XXX select matrix
 	beq m65_scnkey_no_key
 
+	; FALLTROUGH
+
 m65_scnkey_output_key:
 
 	;
@@ -154,6 +159,11 @@ m65_scnkey_output_key:
 	cmp XMAX
 	+bcs scnkey_buffer_full
 
+	; Reinitialize secondary counter
+
+	lda #$03
+	sta KOUNT
+
 	; Put the key into the keyboard buffer
 
 	tya

src/kernal/keyboard_m65/mega65_scnkey_set_kaytab.s

@@ -0,0 +1,35 @@
+;; #LAYOUT# M65 KERNAL_C #TAKE
+;; #LAYOUT# *   *        #IGNORE
+
+;
+; MEGA65 native mode version of a well-known Kernal routine, described in:
+;
+; - [CM64] Computes Mapping the Commodore 64 - pages 220, 221
+;
+
+
+m65_scnkey_set_keytab:
+
+	; Set initial KEYTAB value
+	lda #<kb_matrix
+	sta KEYTAB+0
+	lda #>kb_matrix
+	sta KEYTAB+1
+
+	; Calculate table index
+	lda SHFLAG
+	asl                          ; multiply by 2 - keyboard matrix lookup table consists of words
+	and #$2E                     ; we are interested in SHIFT, VENDOR, CTRL and CAPS LOCK keys only
+	tax
+	and #$20                     ; isolate CAPS LOCK bit
+	beq @1
+	txa                          ; we have to move the CAPS LOCK bit (only) by one position down
+	and #$0E
+	ora #$10
+	tax
+@1:
+
+	; XXX finish the implementation
+
+
+	jmp scnkey_toggle_if_needed