Hi,

I'm a part time tinkering when it comes to coding - just dabbling now and again, and I wondered if anyone had any ideas on how to speed up the following code please?

I want to draw a screen full of random CHR$ characters, but this method is taking approx 13 seconds to run!

function _init()
cls(1)
b=1
i=1
end

function _update()
i=i+5
print(chr(rnd(128)),i,b,7)
if i>=120 then
b=b+8
i=0
if b>=125 then
stop()
end
end
end

Any help would be much appreciated :-)

Thank you

_DRAW and _UPDATE (and _UPDATE60) are frame dependent. These Functions act like a Loop, but the next "turn" will be started after a Frame, which makes it way too slow.

A possible Solution is: Make your own "Inner-Loop" that runs on exactly one Frame. Here's an example using REPEAT...UNTIL:

function _init()
 cls(1)
end

function _update()
 screen_full_of_chars()
end

function screen_full_of_chars()
 b=1
 i=1
 repeat
  i=i+5
  print(chr(rnd(128)),i,b,7)
  if i>=120 then
   b=b+8
   i=0
  end
 until b>=125
 stop() 
end

I must confess that I'm not really satisfied about this Solution either, because every Command that writes something to Screen should be included inside the _DRAW-Function, like the PRINT-Command... So I've rewritten it a bit^^:

function _init()
 cls(1)
 ptable = {}
end

function _update()
 fill_ptable()
end

function _draw()
 draw_ptable()
 stop()
end

function fill_ptable()
 for y=1,16 do
  ptable[y] = {}
  for x=1,24 do
   ptable[y][x] = chr(rnd(128))
  end
 end
end

function draw_ptable()
 for y=1,16 do
  for x=1,24 do
   print(ptable[y][x],x*5,(y-1)*8+1,7)
  end
 end
end

A 2D-Table called "ptable" includes every Char and will be filled by the "fill_ptable"-Function. Inside the _DRAW-Function, it iterates through that Table ("draw_ptable") and PRINTs every Char...

Not exactly what you asked for but here is something that allows you to mostly the same.

I see though that you were trying to seperate the chars a little bit.

see if it meets your needs or not

function _init()
	cls(1)
	b=1
	i=1
	flat = ""
	changed = false
end

function _update()
 -- could do with a string buffer
 if btn(❎) or flat=="" then
 	flat=""
		for b = 1,125,5 do
			for i = 1,120,5 do
			 -- first 32 chars are control
			 -- and can have strange effects
			 -- feel free to remove the -32+32
				flat = flat..chr(rnd(128-32)+32)
			end
			flat = flat .. "\n"
		end
		changed =true
	end
end

function _draw()
 if (changed) then
	 cls(1)
		print (flat,0,0,7)
	end
end

Wow!

Thanks for the really speedy response, and the explanations. Can't believe how much faster (almost instantaneous almost!) this method is.

I'll be sure to get my head around this and use it in the future :-)

Thanks again - much appreciated!