YA scifi novel where handedness is referred to as north and south instead of left and right

Question

Can you help me find the title (and hopefully the author) of a young adult sci-fi novel which I started reading 15-20 years ago? [~1990~1996, maybe] I never finished the book and I still really want to. I can't remember the author or the title, but; I know it was a paperback.

Details I remember:

• The setting is futuristic, there is high-tech available but it is not common. Females appear to hold governance and positions of power, and seem to greatly outnumber males.
• Children approaching adulthood go through a kind of choosing/allocation ceremony where they are allocated a robe colour, e.g. blue, yellow etc. which may be tied to a function in society. Grey-robes have a mysterious or unknown function and are treated with caution or fear.
• Our protagonist is a boy who carries a disability in that his left arm is deformed and weak. He's suffered for this during his childhood.
• The story starts around about the time he's going through the allocation event and he is surprised to find himself allocated a black robe. This is unprecedented - black robes don't exist. It causes a significant stir.
• His assigned mentor takes him aside and somehow commands the black robe to change colour to grey. The boy is allowed to continue wearing it and is told he's now a grey robe.
• An AI which seems to be installed in the robe 'awakens' and begins talking to him. I think the AI has a female voice or personality.
• The AI is out of date; she struggles to determine the new culture and rules of this future. One conversation she has with him is when she mentions his arm and it plays out along the lines of:

"What's wrong with your left arm?" [protagonist] frowns, left arm? He hadn't left his arm anywhere! "What are you talking about" he asks. [AI] sighs and says patiently: "I'm sorry, let me try again. I can see one of your arms is weaker than the other." [protagonist] nods. "Which one is it?" He replies: "My north arm."

That's about all I can remember of the book and I don't think I made it very far in. I would love to find and read this book - can anyone help me?!

EDIT: Details I'm hazy on:

• It may have been written by a New Zealand author, because I think I read it while attending a New Zealand Primary School (ages 5-12).
• I don't think it was written by Ken Catran, none of his titles stand out as being this book, but I was reading a lot of his work at that time, so; it could be one of his. I haven't been able to find decend blurbs for a lot of his titles.

Answer 1

I think you are looking for The Seventh Robe by Ged Maybury

I think I read the same book in around 1995, and found this page while looking for it, the added information that it was likely an NZ author led me to the Amazon page

I recall this book having the AI robe that was black, and I think they are given to the children in some kind of egg that opens. The robes have push-buttons on the inside of one sleeve that control machines around the city, but the black robe has an extra button. I think the robe changes it's colour to grey when the protagonist requests it. And later the protagonist is stripped of their black robe and given a new one, and the AI finds them in the new robe.

The people in the setting have forgotten that machines and computers exist, and they run the place as a religious order.

The cover on that Amazon page matches my recollection.

The cover includes black and grey robes in the foreground, and other colors in the background.