OSLO (AFP) - A rambling 1,500-page tract apparently written by the Norwegian man accused of killing at least 92 people in twin attacks says he has been preparing the operation since at least autumn 2009.

The Internet document is part diary, part bomb-making manual and part political rant in which Anders Behring Breivik details his Islamophobia, attacks on Marxism and his initiation as a Knight Templar.

One entry titled "Autumn 2009 -- Phase Shift" explains how he set up front mining and farming businesses to prepare the attacks for which he was arrested on Friday.

"The reasoning for this decision is to create a credible cover in case I am arrested in regards to the purchase and smuggling of explosives or components to explosives - fertiliser," the tract says.

At least 85 people died in the massacre of youngsters attending a Labour Party summer camp on Utoeya and seven more were killed in an earlier car bomb explosion which ripped through government buildings in Oslo.

"I will be labeled as the biggest (Nazi-) monster ever witnessed since WW2," the text's author writes, while discussing the preparation of his "martyrdom operation".

While the text is signed under the pseudonym "Andrew Berwick", the author explains the origins of his real name -- Anders Behring Breivik.

"My name, Breivik, can be dated back to even before the Viking era. Behring is a pre-Christian Germanic name which is derived from Behr, the Germanic word for Bear...  Anders (Andreas) is the Scandinavian equivalent of... Andrew."

The text refers to the author's friends, their habits, girlfriends and sexual habits, as well as many of the mundane details of day-to-day life, including drinking expensive wine ahead of the attacks.

"I have written approximately half of the compendium myself. The rest is a compilation of works from several courageous individuals throughout the world.

The content of the compendium truly belongs to everyone."

He writes about increased aggression because of taking body-building products, and includes question and answer sessions with himself.

"Q: Name one living person you would like to meet?

A: The Pope or Vladimir Putin. Putin seems like a fair and resolute leader worthy of respect. Im unsure at this point whether he has the potential to be our best friend or our worst enemy though."

"I'm an extremely patient and a very positively minded individual," the author writes in the text that includes a glossary and tips on farming.

But by July of this year, patience had run out and preparations were proceeding apace.

"Sunday July 17: Continued removing traces of the decor on the rental car.

Washed twice with acetone then another round of degreasing. There are still significant traces but at this point I do not have time to take additional measures.

"I believe this will be my last entry. It is now Fri July 22nd, 12.51 Sincere regards, Andrew Berwick, Justiciar Knight Commander, Knights Templar Europe, Knights Templar Norway."

Behring Breivik's lawyer told Norwegian television on Saturday that he had admitted responsibility for the attacks.

"He explained that it was cruel but that he had to go through with these acts," lawyer Geir Lippestad said, adding that the attacks were "apparently planned over a long period of time".