Steve Jobs, in pain and too weak to climb stairs a few weeks before his death, wanted his children to understand why he wasn't always there for them, according to the author of his highly anticipated biography.

Photo taken on Oct. 5, 2011 shows photo of Steve Jobs on the front page of www.apple.com. Apple Board of Directors announced that co-founder and former Chief Executive Officer Steve Jobs passed away on Wednesday. [Xinhua]

"I wanted my kids to know me," Jobs was quoted as saying by Pulitzer Prize nominee Walter Isaacson, when he asked the Apple Inc co-founder why he authorized a tell-all biography after living a private, almost ascetic life.

"I wasn't always there for them, and I wanted them to know why and to understand what I did," Jobs told Isaacson in their final interview at Jobs' home in Palo Alto, California.

The authorized biography Steve Jobs, written by Isaacson, the former managing editor of Time magazine and current chief executive of the Aspen Institute, is currently the No 1 bestseller on Amazon's customer purchase list.

The release date for the biography has been pushed up to Oct 24 in the wake of the Apple co-founder's death on Wednesday, according to a spokesman for publishing house Simon & Schuster. The book was originally planned for release on Nov 21.

Isaacson said he visited Jobs for the last time a few weeks ago and found him curled up in some pain in a downstairs bedroom. Jobs had moved there because he was too weak to go up and down the stairs, "but his mind was still sharp and his humor vibrant," Isaacson wrote in an essay on time.com that will be published in the magazine's Oct 17 edition.

Meanwhile, Bluewater Productions said it was rushing out a special edition e-book of its forthcoming comic book on Jobs.

The 32-page comic titled Steve Jobs: Founder of Apple can be purchased on the NOOK and Kindle reading devices starting Thursday. The print edition is due for release at the end of October, with a portion of the profits from both issues going to the American Cancer Society.

In addition, a new play about Steve Jobs, the public's love affair with the devices he created, and the human cost of creating them, will go ahead next week despite his death, theater representatives said.

The off-Broadway one-man show, The Agony and the Ecstasy of Steve Jobs, will open at The Public Theater in New York on Oct 17 with previews beginning next week.

The play is not a straight homage to Jobs, but rather a "hilarious and harrowing tale of pride, beauty, lust and industrial design," by performer Mike Daisey. It looks at Jobs' technology obsessions while sharing his own stories of touring iPod and iPhone factories in China, the theater company said.

"This moment is an opportunity to peel back the surface and get at the secret heart of our relationship with Steve Jobs, his devices, our labor, and China itself," said Daisey in a statement.

"Steve Jobs had an enormous impact on our lives. In many ways, the world he has left to us is his world. This is a perfect moment to contemplate that world, its values and practices, and decide what parts of his legacy we should embrace and what parts we need to reject," Daisey said.

Jobs died on Wednesday at the age of 56 after a long battle with a rare form of pancreatic cancer.

Outpourings of sympathy swept across the globe as state leaders, business rivals and fans paid respect to the man who touched the daily lives of countless millions through the Macintosh computer, iPod, iPhone and iPad.

Jobs had struggled with health issues but said very little about his battle with cancer since an operation in 2004. When he stepped down in August, handing the CEO reins to long-time operations chief Tim Cook, Jobs said simply that he could no longer fulfill his duties as chief executive.

Apple has been similarly guarded about the circumstances of his death, saying only that their chairman was surrounded by his wife Laurene and immediate family. Jobs had four children from two relationships.

Funeral arrangements have not been disclosed and it is uncertain when the company will hold a planned "celebration" of Jobs' life. Officials in Sacramento said there will be no state or public funeral.