If you (or your spouse) are self-employed, then you can submit your form by as late as September 1. It is quite in order for one tax form and a couple with one self employed.

I used to have to ask for the Hilfsblatt A each time, but now I use the downloadable system from the ZH tax website. This has all sorts of extra 'blatts' on it. It's quite good because it reads you details from the last year's form and so fills in page 1 before you start.

I'd write off you computer stuff as soon as possible, Basically it's worthless after 3 years, so write it down quickly or as Swiss Bob says asap...