You can definitely do Soft Dev without 1/2. Of course, having that base knowledge of 1/2 before going into Softdev would be
ideal, but it is in no way a requirement. If you have been exposed, that is a
good start. I remember in school, I did IT Applications (now what is known as Informatics) without 1/2 and I did just fine (40 SS). VCE Computing is not that stimulating or exciting - therefore you need a passion to keep powering through to get that good study score.
In terms of 1/2, I would classify 1/2 as a foundation for further 3/4 study in the area of Computing. You may find a bit of overlap. From there, you can choose either (or a combo of):
* Informatics 3/4
* Softdev 3/4
* Algorithmics 3/4 (technically not part of the VCE Computing curriculum & is relatively new - but if you are interested in Computer Science as a uni pathway and have a strong maths background, I would definitely recommend looking into this. Prereq is Methods 1/2 - but you could probably get away with doing it at the same time).
So, to answer your question: it is
absolutely possible. You do a bit of programming - but your teacher should be in a position where he or she can guide you through that process. I would definitely be going with SD as opposed to the other option, Informatics. That was dry.
Have you had a look at the study design for Computing? That's a great place to get vital information about each option. Basically (if you are unaware of what a study design is), it is a document which outlines everything you need to know about VCE subjects (e.g. the content and skills that one is taught, the assessment requirements and so on). Here's the link if you haven't already got it:
http://www.vcaa.vic.edu.au/Documents/vce/computing/ComputingSD-2016.pdfGood luck