How can I get past Darwin showing up on my screen. i-book g3. hasn't been started in years and when I try it spins forever (like 1-1/4 hr.) and then goes to a black darwin sceen. I tried booting from the disc but I it won't let me see the hard drive

If the HDD isn't visible in Disk Utility then it is dead and will need to be replaced. When you boot the computer the hangup is that the OS cannot find a drive from which to load the OS. The last G3 iBook came with 10.4.11. The first G3 iBook came with 10.3.9. Lots of G3 iBook models, so I have no idea which OS version is the minimum requirement for yours.

Of the iBook G3/ G4 models, the G3 could be a source of minor confusion due

to the change from colors model to white G3 model in May 2001. This first white

model has dual USB ports and other improvements over the older early G3...

Early colors aka 'clamshell' iBook G3 appeared in 1999; first ran MacOS8.6.

First 'snow' dual USB white G3 iBook 12-inch/14-inch appeared in May 2001,

it shipped with either (just) MacOS9.1, or later included OS X 10.0.3 (4P13.)

'iBook G4' arrived by Oct 2003 & was replaced by newer model by April 2004.

• If you have an iBook G3 dual USB (white) the guide to replace a hard disk drive:

https://www.ifixit.com/Guide/iBook+G3+12-Inch+Hard+Drive+Replacement/131

I've owned the First white iBook 12-inch 500MHz G3, 64MB RAM/10GB HD (05/01)

& still have my Last white iBook 12-inch 1.33GHz G4 1.5GB RAM/40GB HD (05/05)

If you can find the product serial number, use of a 'Serial Number Lookup' site

to determine a better determination of the exact build year series, is advised.

The serial number may be under keyboard or in battery compartment.

https://www.powerbookmedic.com/identify-mac-serial.php

You may find the model in the everymac.com 'all ibook specification' database:

http://www.everymac.com/systems/apple/ibook/index-ibook.html

If you could find the media software disc he used to attempt an upgrade in the

old iBook (G3?) that may be helpful for reference; if the disc was from a different

model build series Mac computer, or from a newer Intel-based Mac, it won't work.

And with these older portable computers, their rotational hard drives are long past

their prime. To locate a replacement and know how to swap them without damage

to other components, wires, and follow the process correctly, it a difficult chore.

Maybe online guides can help with DIY repair https://www.ifixit.com/Device/iBook

Three guides for G3 iBook: https://www.ifixit.com/Device/iBook_G3

Four guides for G4 iBook: https://www.ifixit.com/Device/iBook_G4

The hard drive would be a candidate for replacement. If you are set up to diagnose

troubleshoot and repair these older powerPC G3/G4 portables, it's not impossible.

Locating replacement parts, such as the ATA/IDE hard drive, may be harder now.

Also, cables may need replacement after attempting to open the computer.

{Models that could run Leopard 10.5(.8) would need to have a PPC cpu of more than

867MHz. Even so, the last G3 iBook with 900MHz may not run it. My 12-in iBook G4

with 1.33GHz CPU and 1.5GB RAM doesn't like Leopard 10.5.8. Tiger is best, there.}

https://www.apple.com/usergroups/

There may be an Apple User Group in your vicinity with some vintage product users

who may have ideas. Most 'apple authorized service providers' may balk if asked...

Also, the logic board may have a failed component. Try the HDD first, because the

in-out ATA controller device that appears to have failed may just be in the HDD.

But it may also be a shared component that allows optical drive to work, or not.

In any event...

Good luck & happy computing! 🙂

Where are you running Disk Utility from? Newer Disk Utility can break older OS's if they are not the same version.

These old Macs never had any recovery system or internet recovery. All you can do is run the software install disks that support the model to reinstall & repair the OS.

You can try running an fsck in single user mode (that is the same as Disk Utility's repair disk option).

How to start up your Mac in single-user or verbose mode - Apple Support

The command prompt normally lists the command to run to do a filesystem check & repair…

/sbin/fsck -fy

Type 'reboot' when it stops reporting errors or re-run it.

I doubt you can recover this without erasing & reinstalling an OS that works with that model. Do you have any other Macs to allow you to backup the Mac in this broken state? Target disk mode & a firewire cable may help you get the data off (ignore the reference to Mountain Lion - it works with many older OS's).

OS X Mountain Lion: Transfer files between two computers using target disk mode