;; #LAYOUT# STD *       #TAKE
;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
;; #LAYOUT# *   BASIC_0 #TAKE
;; #LAYOUT# *   *       #IGNORE

; Well-known BASIC routine, described in:
;
; - [CM64] Computes Mapping the Commodore 64 - page 97
; - https://www.c64-wiki.com/wiki/BASIC-ROM
; - https://csdb.dk/forums/?roomid=11&topicid=137233
; 

; XXX use this routine to initialize TXTPTR

RUNC:
	; According to WIKI, we should load $7A/$7B with $2B-1/$2C-1), this does not makes sense.
	; But CSDB claims, that it should 'set current character pointer to start of basic - 1' - this
	; looks sane, also checked that the original BASIC routine does this (short test program)

	; Lets initialize TXTPTR using TXTTAB

	lda TXTTAB+0
	sec
	sbc #$01
	sta TXTPTR+0
	
	lda TXTTAB+1
	sbc #$00
	sta TXTPTR+1

	rts