********************************
*                              *
* SYMBOLS                      *
*                              *
* AUTHOR:  BILL CHATFIELD      *
* LICENSE: GPL2                *
*                              *
********************************

RNDL	EQU	$4e	;Continuously incremented while waiting for keyboard input
RNDH	EQU	$4f	;High byte of RNDL
FACEXP	EQU	$9d	;Address of FAC exponent used by FADDT,FSUBT,FMULTT,FDIVT

********************************
*                              *
* MEMORY MAPPED INPUT/OUTPUT   *
* ADDRESSES $C000 - $C0FF      *
*                              *
********************************

KBD EQU $C000 ;BIT 7 IS 1 IF KEY PRESSED
KBDSTRB EQU $C010 ;CLEARS KBD BIT 7
CLR80STO EQU $C000 ;ALLOW PAGE2 PG1 & PG2 SWITCHING
SET80STO EQU $C001 ;ALLOW PAGE2 MAIN & AUX SWITCHNG
STO80 EQU $C018 ;1=PAGE2 SWITCHES MAIN/AUX
   ;0=PAGE2 SWITCHES VIDEO PAGES
CLR80VID EQU $C00C ;TURN OFF 80-COL DISPLAY
SET80VID EQU $C00D ;TURN ON 80-COL DISPLAY
COL80 EQU $C01F ;0=40 COL IS ON, 1=80 COL IS ON
TEXTOFF EQU $C050 ;SELECTS GRAPHICS MODE
TEXTON EQU $C051 ;SELECTS TEXT MODE
TEXT EQU $C01A ;1=TEXT MODE ACTIVE,0=GRAPH MODE
MIXEDOFF EQU $C052 ;USE FULL-SCREEN GRAPHICS
MIXEDON EQU $C053 ;USE GRAPHICS WITH 4 LINES TEXT
MIXED EQU $C01B ;0=FULL SCREEN, 1=MIXED
PAGE2OFF EQU $C054 ;SELECTS PAGE1 OR MAIN VID MEM
PAGE2ON EQU $C055 ;SELECTS PAGE2 OR AUX VID MEM
PAGE2 EQU $C01C ;1=VID PG2 SELECTED OR AUX SEL
HIRESOFF EQU $C056 ;SELECTS LOW-RES GRAPHICS
HIRESON EQU $C057 ;SELECTS HIGH-RES GRAPHICS
HIRES EQU $C01D ;0=LOW-RES, 1=HIGH-RES

********************************
*                              *
* SUBROUTINES PROVIDED BY      *
* APPLESOFT BASIC              *
* IN READ-ONLY MEMORY          *
* ADDRESSES $D000 - $F7FF      *
*                              *
********************************

STROUT EQU $DB3A ;PRINT STRING IN Y,A
GIVAYF EQU $E2F2 ;CONVERT 2-BYTE INT A(HI) Y(LO) TO FLOAT IN FAC
CONINT EQU $E6FB ;CONVERT FAC TO BYTE IN X, ERR IF FAC > 255
FADD EQU $E7BE ;FAC = MEM + FAC, MEM ADDR IS Y(HI) A(LO)
FSUB EQU $E7A7 ;FAC = MEM - FAC, MEM ADDR IS Y(HI) A(LO)
FMULT EQU $E97F ;FAC = MEM * FAC, MEM ADDR IS Y(HI) A(LO)
FDIV EQU $EA66 ;FAC = MEM / FAC, MEM ADDR IS Y(HI) A(LO)
FADDT EQU $E7C1 ;FAC = ARG + FAC, MUST LOAD FACEXP INTO A FIRST
FSUBT EQU $E7AA ;FAC = ARG - FAC, MUST LOAD FACEXP INTO A FIRST
FMULTT EQU $E982 ;FAC = ARG * FAC, MUST LOAD FACEXP INTO A FIRST
FDIVT EQU $EA69 ;FAC = ARG / FAC, MUST LOAD FACEXP INTO A FIRST
MUL10 EQU $EA39 ;MULTIPLY FAC BY 10
FCOMP EQU $EBB2 ;COMP MEM TO FAC
QINT EQU $EBF2 ;CONVERT FAC TO INTEGER
FLOAT EQU $EB93 ;CONVERT A TO FAC, I THINK
MOVAF EQU $EB63 ;MOVE FAC INTO ARG
MOVMF EQU $EB2B ;MOVE FAC TO MEMORY Y,X
MOVFA EQU $EB53 ;MOVE ARG TO FAC
MOVFM EQU $EB2B ;MOVE MEMORY TO FAC
INT EQU $EC23 ;APPLESOFT INT FUNCTION
PRINTFAC EQU $ED2E ;PRINT FAC. USES FOUT,STROUT
FOUT EQU $ED34 ;FAC TO STRING, FAC DESTROYED
RND EQU $EFAE ;APPLESOFT RND FUNCTION

********************************
*                              *
* SUBROUTINES PROVIDED BY      *
* SYSTEM MONITOR PROGRAM       *
* IN READ-ONLY MEMORY          *
* ADDRESSES $F800 - $FFFF      *
*                              *
********************************

PLOT EQU $F800 ;PLOT BLOCK ON LOW-RES SCREEN
HLINE EQU $F819 ;HORIZONTAL LINE
VLINE EQU $F828 ;VERTICAL LINE
CLRSCR EQU $F832 ;CLEAR LOW-RES SCREEN
CLRTOP EQU $F836 ;CLEAR THE TOP OF LOW-RES
NEXTCOL EQU $F85F ;INCREMENT COLOR BY 3
SETCOL EQU $F864 ;SET LOW-RES GRAPHICS COLOR
SCRN EQU $F871 ;READ THE LOW-RES SCREEN
TEXTCMD EQU $FB2F
TEXTMODE EQU $FB39
GR EQU $FB40 ;BASIC GR COMMAND
WAIT EQU $FCA8
COUT EQU $FDED ;WRITE A CHARACTER
CROUT EQU $FD8E ;WRITE A CARRIAGE RETURN
PRBYTE EQU $FDDA ;PRINT VALUE OF BYTE