flyback smps too much ringing ?

[nigelwright]

I have taken a l6565 circuit and replaced the l6565 with a PIC micro.
On the output of the transformer I ma getting a lot of ringing.
Does anyone know how to get rid of this ?
http://www.ckp-railways.talktalk.net/00.jpg

 

[MicrosiM]

why did you replace the l6565 with pic micro?

 

[nigelwright]

I wanted to see if I could do it more simply using a PIC.
THis has simplified the transformer as I dont need a low voltage feedback winding.

 

[nigelwright]

I cracked the ringing with a primary snubber.