08M2 welder flicker simulation

Hi all,
Well I'm sure others have done this, but here is my two pennuth.
I wanted to simulate the flicker of a welding torch / mig welder for our garden railway layout.
So using ultra-bright blue and white LEDs I wrote this simplistic program.

'  This program runs on a PICAXE-08M2.
'  Used to flicker LEDs on pin 5 & 7
'  to simulate welding flicker
'  Wire white LED from pin 5 to ground via suitable resistor
'  Wire blue LED from pin 7 to ground via a suitable resistor
'  I used 220R resistors in both cases.
'  The original 'tune' was The Magic Roundabout theme ring tone!!

' === Directives ===
#picaxe 08M2       ' specify processor

' ============= Begin Main Program =============
	random w0
	let w1 = b0*21
	tune 3, 2,($27,$67,$67,$22,$22,$24,$64,$64,$20,$20,$25,$65,$65,$20,$20,$26,$66)
	pause w1
	random w0
	let w1 = b0*25
	tune 3, 2,($27,$67,$67,$22,$22,$24,$64)
	pause w1
	random w0
	let w1 = b0*19
	tune 3, 2,($27,$67,$67,$22,$22,$24,$64,$64,$20,$20,$25)
	pause w1	
loop	'carry on indefinately
I am pleased with the effect it creates :rolleyes:, YMMD

Cobbled this together and it works great. Don't understand the 'Tune' command, fist argument is '3', supposed to refer to pin output, but the outputs are on physical pins 5 and 7 (c.2 & c.0 on 08M2) so what does the 3 stand for.
At anyrate this is great for my son-in-laws HO train layout.