screen editor now supports tabulators

c64/kernal/keyboard/kb_matrix.s

@@ -51,6 +51,10 @@ __kb_matrix_ctrl:
 	.byte $9C,$12,$04,$1E,$03,$06,$14,$18
 	.byte $1F,$19,$07,$9E,$02,$08,$15,$16
 	.byte $12,$09,$0A,$92,$0D,$0B,$0F,$0E
+#if CONFIG_EDIT_TABULATORS
+	.byte $00,$10,$0C,$00,KEY_TAB_FW,$1B,$00,KEY_TAB_BW
+#else
 	.byte $00,$10,$0C,$00,$00,$1B,$00,$00
+#endif
 	.byte $1C,$00,$1D,$00,$00,$1F,$1E,$00
 	.byte $90,$06,$00,$05,$00,$00,$11,$00

c64/kernal/keyboard/scnkey.s

@@ -337,18 +337,6 @@ scnkey_output_65_no_shift:
 !:
 	lda (KEYTAB), y	                   // retrieve key code from standard matrix
 
-	// XXX this will be needed for extended screen editor and C128 keyboard
-
-	// cmp KEY_TAB_FW                  // special handling for SHIFT+TAB
-	// bne scnkey_got_petscii          // XXX or to scnkey_handle_caps_lock
-	// lda SHFLAG                      // special handling for SHIFT+TAB
-	// and #KEY_FLAG_SHIFT
-	// bne !+
-	// lda KEY_TAB_FW
-	// bne scnkey_got_petscii          // branch alWAYS 
-    // !:
-	// lda KEY_TAB_BW                  // bne scnkey_got_petscii if CAPS LOCK is handled
-
 #endif // CONFIG_KEYBOARD_C128 or CONFIG_KEYBOARD_C65
 
 #if CONFIG_KEYBOARD_C128_CAPS_LOCK || CONFIG_KEYBOARD_C65_CAPS_LOCK
@@ -391,6 +379,22 @@ scnkey_handle_caps_lock:
 
 scnkey_got_petscii:
 
+#if CONFIG_KEYBOARD_C128 && CONFIG_EDIT_TABULATORS
+
+	// Special handling for SHIFT+TAB; it is easier than creating new matrix
+
+	tax
+	cmp #KEY_TAB_FW
+	bne !+
+	lda SHFLAG
+	and #KEY_FLAG_SHIFT
+	beq !+
+	ldx #KEY_TAB_BW
+!:
+	txa
+
+#endif // CONFIG_KEYBOARD_C128 and CONFIG_EDIT_TABULATORS
+
 	beq scnkey_no_keys                 // branch if we have no PETSCII code for this key
 	ldy NDX
 	sta KEYD, y

c64/kernal/screen/chrout_screen_crsr.s

@@ -12,6 +12,7 @@ chrout_screen_CRSR_UP:
 	sta PNTR
 	jmp chrout_screen_calc_lptr_done
 
+
 chrout_screen_CRSR_DOWN:
 
 	lda PNTR
@@ -25,15 +26,17 @@ chrout_screen_CRSR_DOWN:
 	jsr screen_scroll_up_if_on_last_line
 	jmp chrout_screen_calc_lptr_done
 
+
 chrout_screen_CRSR_LEFT:
 
 	lda TBLX
 	ora PNTR
-	beq !+ // recalculating pointer is not really necessary, but this is a very rare case nevertheless
+	beq !+ // top-left corner, recalculating pointer is not necessary, but this is a very rare case nevertheless
 	dec PNTR
 !:
 	jmp chrout_screen_calc_lptr_done
 
+
 chrout_screen_CRSR_RIGHT:
 
 	inc PNTR

c64/kernal/screen/chrout_screen_jumptable_codes.s

@@ -24,6 +24,10 @@ __chrout_screen_jumptable_quote_guard:
 
 #if CONFIG_EDIT_STOPQUOTE
 	.byte KEY_STOP
+#endif
+#if CONFIG_EDIT_TABULATORS
+	.byte KEY_TAB_BW
+	.byte KEY_TAB_FW
 #endif
 	.byte KEY_INS
 	.byte KEY_DEL
@@ -48,6 +52,10 @@ chrout_screen_jumptable_lo:
 	.byte <(chrout_screen_CRSR_UP    - 1)
 #if CONFIG_EDIT_STOPQUOTE
 	.byte <(chrout_screen_STOP       - 1)
+#endif
+#if CONFIG_EDIT_TABULATORS
+	.byte <(chrout_screen_TAB_BW     - 1)
+	.byte <(chrout_screen_TAB_FW     - 1)
 #endif
 	.byte <(chrout_screen_INS        - 1)
 	.byte <(chrout_screen_DEL        - 1)
@@ -69,6 +77,10 @@ chrout_screen_jumptable_hi:
 	.byte >(chrout_screen_CRSR_UP    - 1)
 #if CONFIG_EDIT_STOPQUOTE
 	.byte >(chrout_screen_STOP       - 1)
+#endif
+#if CONFIG_EDIT_TABULATORS
+	.byte >(chrout_screen_TAB_BW     - 1)
+	.byte >(chrout_screen_TAB_FW     - 1)
 #endif
 	.byte >(chrout_screen_INS        - 1)
 	.byte >(chrout_screen_DEL        - 1)

c64/kernal/screen/chrout_screen_tab.s

@@ -0,0 +1,33 @@
+
+//
+// Tabulation keys handling within CHROUT
+//
+
+
+#if CONFIG_EDIT_TABULATORS
+
+
+chrout_screen_TAB_FW:
+
+	lda PNTR
+	ora #%00000111
+	sta PNTR
+	inc PNTR
+	jmp chrout_screen_calc_lptr_done
+
+
+chrout_screen_TAB_BW:
+
+	lda TBLX
+	ora PNTR
+	beq !+ // top-left corner, recalculating pointer is not necessary, but this is a very rare case nevertheless
+
+	dec PNTR
+	lda PNTR
+	and #%11111000
+	sta PNTR
+!:
+	jmp chrout_screen_calc_lptr_done
+
+
+#endif // CONFIG_EDIT_TABULATORS