>Yes i know what you say, but imagine that i have to print 500 pages(original) and 1000(copies)
>
> (tray2) (tray3)
>simultaneos prints an original one and then a copy is printed until the 1500 impressions... (500+1000)=1500 serious slow cpu no?
>
>
>Thank...

Can't you print the 500 copies on the original printer before switching to the other printer. Actually, you have me a bit confused because you started off by asking how to change trays for each page and now you're talking about changing printers. Can you detail a bit more of what exactly you need?