' MUXprog.bas
' BS1 code for Setsnest 20x20 AV Matrix switch
'
' v0.1 12/17/2002
' First working version
'
DIRS = %00000111
SYMBOL Mux1 =  %01111000	'input 1
'SYMBOL Mux2 =  %01111001	'input 2
'SYMBOL Mux3 =  %01111010	'input 3
SYMBOL strobe = 0
SYMBOL data = Pin1
SYMBOL clock = 2
SYMBOL I = B2
SYMBOL J = B3
SYMBOL SerData = B4
SYMBOL Pwidth = B5

'reset clock and strobe lines to low
Low clock
Low strobe

' Init all outputs to input 1
B0 = Mux1	'input 3 has no video
Gosub shiftout
For J = 1 to 21
	B0 = Mux1	'input 1
	Gosub shiftout
	Next J
pulsout strobe,1
'Gosub checkvid

' Main program
main: 	serout 6,N2400,("Matrix ready:")
	'debug "Matrix ready:", CR
	serin 7,N2400,SerData
	if SerData = 86 Then checkvid
	if SerData = 66 Then binmode
	if SerData = 67 Then charmode
	goto main

binmode: For J = 1 to 21
	serin 7,N2400,SerData
	'debug #J,SerData,CR
	if SerData = 76 then latch
	B0 = SerData
	Gosub shiftout
	Next J
	pulsout strobe,1
	goto main

charmode: For J = 1 to 21
	serin 7,N2400,#SerData
	'debug #J,SerData, CR
	if SerData = 76 then latch
	B0 = SerData
	Gosub shiftout
	Next J
	pulsout strobe,1
	goto main

latch:	pulsout strobe,1
	goto main

shiftout: For I = 1 to 8
	data = Bit0
	toggle clock
	B0 = B0 / 2
	toggle clock
	Next I
	Return

checkvid: pulsin 3,0,Pwidth
	if Pwidth = 0 Then novid
	'Debug "video detected", CR
	serout 6,N2400,(#1,13,10)
	goto main
novid:	'Debug "no video", CR
	serout 6,N2400,(#0,13,10)
	goto main