screen editor now supports tabulators

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