const speaker=$C030
const showgraphics=$C050
const showtext=$C051
const showfull=$C052
const showmix=$C053
const TRUE=$FFFF
const FALSE=$0000
const showpage1=$C054
const showpage2=$C055
const showlores=$C056
const showhires=$C057
const keyboard=$C000
const keystrobe=$C010
const hgr1=$2000
const hgr2=$4000
const page1=0
const page2=1
byte exitmsg[] = "PRESS ANY KEY TO EXIT."
byte goodbye[] = "THAT'S ALL FOLKS!"
byte rebootmsg[] = "PRESS ANY KEY TO REBOOT..."
byte i, j, k, w, fmi, fmk, color
;
; CALL 6502 ROUTINE
; ROMCALL(AREG, XREG, YREG, STATUS, ADDR)
;
asm romcall
TMP	EQU	$06

	PHP
	LDA	ESTKL,X
	STA	TMP
	LDA	ESTKH,X
	STA	TMP+1
	INX
	LDA	ESTKL,X
	PHA
	INX
	LDA	ESTKL,X
	TAY
	INX
	LDA	ESTKL+1,X
	PHA
	LDA	ESTKL,X
	INX
	STX	TMP+2
	TAX
	PLA
	BIT	ROMIN
	PLP
	JSR 	JMPTMP
	PHP
	BIT	LCBNK2
	STA	REGVALS+0
	STX	REGVALS+1
	STY	REGVALS+2
	PLA
	STA	REGVALS+3
	LDX	TMP+2
	LDA 	#<REGVALS
	LDY 	#>REGVALS
	STA 	ESTKL,X
	STY 	ESTKH,X
	PLP
	RTS
JMPTMP:	JMP	(TMP)
REGVALS: DS	4
end
;
; CHAR OUT
; COUT(CHAR)
;
asm cout
	LDA	ESTKL,X
	INX
	ORA	#$80
	BIT	ROMIN
	JSR	$FDED
	BIT	LCBNK2
end
;
; PRINT STRING
; PRSTR(STR)
;
asm prstr
	LDY	#$00
	LDA     ESTKL,X
    STA     TMP
	LDA     ESTKH,X
	STA     TMP+1
	BIT	ROMIN
	LDA     (TMP),Y
	STA     ESTKL,X
	BEQ     :+
_PRS1:	INY
	LDA	(TMP),Y
	ORA	#$80
	JSR	$FDED
	TYA
	CMP	ESTKL,X
	BNE	_PRS1
:	INX
	BIT	LCBNK2
end
def textmode
	drop romcall(0, 0, 0, 0, $FB39)
end
def home
	drop romcall(0, 0, 0, 0, $FC58)
end
def gotoxy(x, y)
	^($24) = x
	drop romcall(y, 0, 0, 0, $FB5B)
end
def crout
	cout($0D)
end
def grmode
	drop romcall(0, 0, 0, 0, $FB40)
	drop ^showlores
end
; grcolor(color)
asm grcolor
	LDA	ESTKL,X
	INX
	STX	TMP+2
	BIT	$C081
	JSR 	$F864
	BIT	$C080
	LDX	TMP+2
end
; grplot(x, y)
asm grplot
	LDA	ESTKL,X
	INX
	LDY	ESTKL,X
	INX
	STX	TMP+2
	BIT	$C081
	JSR 	$F800
	BIT	$C080
	LDX	TMP+2
end
defopt colors
	while TRUE
		for w = 3 to 50
			for i = 1 to 19
				for j = 0 to 19
					k = i + j
					color = (j * 3) / (i + 3) + i * w / 12
					fmi = 40 - i
					fmk = 40 - k
					grcolor(color);
					grplot(i, k);
					grplot(k, i);
					grplot(fmi, fmk);
					grplot(fmk, fmi);
					grplot(k, fmi);
					grplot(fmi, k);
					grplot(i, fmk);
					grplot(fmk, i);
					if ^keyboard >= 128
						drop ^keystrobe
						return
					fin
				next
			next
		next
	loop
end

grmode()
home()
gotoxy(10,22)
prstr(@exitmsg)
colors()
textmode()
home()
prstr(@goodbye)
while ^keyboard < 128
loop
drop ^keystrobe
done