poke

poke*

This API was extended in version 0.9 and 1.0.

• poke(addr, val)
• poke(addr, val, [bits=8]) added in 0.9
• poke4(addr4, val4)
• poke2(addr2, val2) added in 1.0
• poke1(bitaddr, bitval) added in 1.0

Or using bits argument:

• poke(addr4, val4, bits=4)
• poke(addr2, val2, bits=2)
• poke(bitaddr, bitval, bits=1)

Parameters

• addr : the address of RAM you desire to write (segmented based on bits)
• val : the integer value write to RAM (range varies based on bits)
• bits : the number of bits to write (1, 2, 4, or 8; default: 8)

Description

This function allows you to write directly to RAM. The requested number of bits is written at the address requested. The address is typically specified in hexadecimal format.

For in-depth detail on how addressing works with various bits parameters, please see peek.

See also:

• peek - Read from a memory address

Examples

• Edit the palette.
• Change mouse cursor.
• Change TIC-80 border color.
• Change number of bits per pixels.
• Sky gradient.

Glitch effect

-- 'Change screen offset in every scanline' demo
-- author: Vadim
shake=0
d=4
function TIC()
	if btnp()~=0 then shake=30 end
	if shake>0 then
		poke(0x3FF9+1,math.random(-d,d))
		shake=shake-1
		if shake==0 then memset(0x3FF9,0,2) end
	end
	cls(12)
	print("PRESS ANY KEY TO GLITCH!",54,64)
end

function BDR(row)
	if shake>0 then
		poke(0x3FF9,math.random(-d,d))
	end
end

Video noise

-- demo poke
function TIC()

--Make some video noise
for i=0,(240*136)/2-1 do
 poke(0x0000+i,(i*i*time())/3000000000%2+1)
end

--Sound it
m=0
for i=30,80 do
 m=m+peek(0x0000+6000+i)
end
f=math.floor((10+((1+m)/20))*400)
poke(0xFF80+0,f&0XFF)
poke(0xFF80+2,(f&0XFF00)>>8)
poke(0xFF80+8,f&0XFF)
poke(0xFF80+10,(f&0XFF00)>>8)

end

Video noise 2 player mode

-- demo poke
l1=49
w1=18
l2=21
w2=12

function TIC()

--Video noise
for i=0,(240*136)/2-1 do
 poke(0x0000+i,(i*i*time())/3000000000%2+1)
end

--Sounds
if btnp(0,3,3)then l1=l1-1 end
if btnp(1,3,3)then l1=l1+1 end
if btnp(2,3,3)then w1=w1-1 end
if btnp(3,3,3)then w1=w1+1 end

l1=l1<136 and l1 or 135
l1=l1>0 and l1 or 0
w1=w1<120 and w1 or 112
w1=w1>2 and w1 or 2

if btnp(8,3,3)then l2=l2-1 end
if btnp(9,3,3)then l2=l2+1 end
if btnp(10,3,3)then w2=w2-1 end
if btnp(11,3,3)then w2=w2+1 end

l2=l2<136 and l2 or 135
l2=l2>0 and l2 or 0
w2=w2<120 and w2 or 112
w2=w2>2 and w2 or 2

--S1
off1=l1*120
m=0
for i=60-w1/2,60+w1/2 do
	m=m+peek(0x0000+off1+i)
end

f=(10+((1+m)/w1))*800
f=math.floor(f)
print(l1..'-'..w1..'-'..f,0,0)
poke(0xFF80+0,f&0XFF)
poke(0xFF80+2,(f&0XFF00)>>8)

--Draw line
for i=60-w1/2,60+w1/2 do
	poke(0x0000+off1+i,136)
end

--S2
off2=l2*120
m=0
for i=60-w2/2,60+w2/2 do
	m=m+peek(0x0000+off2+i)
end

f=(10+((1+m)/w2))*800
f=math.floor(f)
print(l2..'-'..w2..'-'..f,0,10)
poke(0xFF80+8,f&0XFF)
poke(0xFF80+10,(f&0XFF00)>>8)

--Draw line
for i=60-w2/2,60+w2/2 do
	poke(0x0000+off2+i,102)
end

end

Other examples of poke usage in code snippets.