; Copyright 2018 faddenSoft. All Rights Reserved.
; See the LICENSE.txt file for distribution terms (Apache 2.0).
;
; Sources:
;  What's Where in the Apple, by William F. Luebbert

*SYNOPSIS Applesoft BASIC addresses and constants

HCOLOR1     @ $1C       ;hi-res color mask
COUNTH      @ $1D       ;hi-res high-order byte of step for line
HBASL       @ $26       ;base address for hi-res drawing

LINNUM      @ $50       ;line number ($50-51)
TEXTTAB     @ $67       ;pointer to start of Applesoft program ($67-68)
VARTAB      @ $69       ;pointer to start of Applesoft variables ($69-6A)
FACMO       @ $A0       ;middle-order byte of mantissa of FAC
FACLO       @ $A1       ;low-order byte of mantissa of FAC
FACSIGN     @ $A2       ;single byte sign of FAC
CHRGET      @ $B1       ;get next character or Applesoft token
CHRGOT      @ $B7       ;get next, but don't advance TXTPTR
TXTPTR      @ $B8       ;points at next char or token

AUTORUN     @ $D6       ;set to $80 to auto-run
ERRFLG      @ $D8       ;$80 if onerr active

HPAG        @ $E6       ;hi-res page to draw on ($20 or $40)
SCALE       @ $E7       ;hi-res graphics scale factor

AMPERV      @ $03F5     ;jump to function that handles Applesoft '&' cmds
AMPERV_     @ $03F6     ;vector to function that handles Applesoft '&' cmds

;
; Useful Applesoft routines.
; TODO: there are many more
;
ERROR       @ $D412     ;print error based on X-reg
FRMNUM      @ $DD67     ;evalute expression at TXTPTR, result into FAC
SYN_ERROR   @ $DEC9     ;throw SYNTAX ERROR
CHKCOM      @ $DEBE     ;checks TXTPTR for comma
ILLQ_ERROR  @ $E199     ;throw ILLEGAL QUANTITY ERROR
GETADR      @ $E752     ;convert FAC to 2-byte integer in LINNUM
GETBYT      @ $E6F8     ;gets byte, in X/FACLO
HFNS        @ $F6B9     ;get hi-res x/y for hplot

;
; Applesoft BASIC tokens.
; TODO: this is a partial set
;
*TAG Applesoft-Tokens
TOK_PLOT    = $8d
TOK_HGR2    = $90
TOK_HGR     = $91
TOK_HCOLOR  = $92
TOK_HPLOT   = $93
TOK_DRAW    = $94
TOK_XDRAW   = $95
TOK_INVERSE = $9e
TOK_CLEAR   = $bd
TOK_NEW     = $bf
TOK_TO      = $c1
TOK_AT      = $c5
TOK_SGN     = $d2
TOK_SCRN    = $d7
TOK_EXP     = $dd
TOK_COS     = $de
TOK_SIN     = $df