Member Avatar for paulandvonn

right were do i start, on my mac i book it as 0s9 and 0sx i swithched to osx and nothing works, no applications work, i heard you can switch back on start up does anybody know how and if so could you please tell me my mac is redundant at the moment thank you paulandvonn :cry:

  • 4 Contributors
  • 3 Replies
  • 268 Views
  • 1 Month Discussion Span
  • Latest Post Latest Post by Warren Oates

Dani AI

Generated

A few practical additions that build on what , and have already said — for cases where the on‑screen boot selector or prefs aren't usable, or you want a persistent or scripted change.

The low‑level tool most admins use is bless. It can mark a mounted HFS+/APFS volume as the firmware’s boot target, do a one‑time boot, or set legacy (non‑EFI) boots. Example (run as root):

# make /Volumes/OtherHD the persistent startup disk
sudo /usr/sbin/bless --mount "/Volumes/OtherHD" --setBoot

# set it for the next boot only, then restart
sudo /usr/sbin/bless --mount "/Volumes/OtherHD" --setBoot --nextonly && sudo reboot

# if you need a legacy (older OS) hint
sudo /usr/sbin/bless --mount "/Volumes/OS9" --setBoot --legacy

See the bless manual for details and options (folder vs mount vs device modes). (keith.github.io)

On macOS there’s also systemsetup, a higher‑level command that lists available startup volumes and sets the startup path (handy for scripts or remote machines over SSH):

sudo systemsetup -liststartupdisks
sudo systemsetup -setstartupdisk "/Volumes/OtherHD"

Apple documents using systemsetup from Terminal for remote/admin tasks. (manp.gs)

Troubleshooting tips: if the machine won’t remember your choice, try resetting NVRAM/PRAM (this clears stored startup info and other settings) and then re‑set the startup disk. Also note that newer macOS security (SIP/T2/Apple Silicon changes) can restrict low‑level tools — on modern systems prefer the supported systemsetup/UI methods or consult the platform docs before forcing firmware changes. Finally, remember that Mac OS 9/Classic behavior differs by hardware generation: Intel and later non‑PowerPC Macs cannot run Classic natively. (support.apple.com)

Use these commands carefully (they require admin rights and affect firmware settings). If the machine is failing to run applications after switching, hardware/installation details (model, installed OS versions, filesystem type) determine the right next steps.

Recommended Answers

All 3 Replies

Member Avatar for yellow

Unless your OS X and OS 9 installs are on different partitions, you can only boot into OS X from OS 9 by holding down X at boot (no, holding down 9 at boot will not boot you into OS 9). If they are on different partitions, hold down Option at boot and choose the startup volume you want to boot from. If you can get to System Preferences and the Startup Disk preference pane, you can choose your OS 9 isntallation to boot from, otherwise, you have to boot from an OS 9 CD and choose your OS 9 startup Folder as the boot folder.

Member Avatar for kc0arf

Hello,

I am curious by the expression that "nothing works". Is this sudden? Brand new computer out of the box? Purchased from a friend?

I'd like to help you repair your OS X installation.

Christian

Member Avatar for Warren Oates

right were do i start, on my mac i book it as 0s9 and 0sx i swithched to osx and nothing works, no applications work, i heard you can switch back on start up does anybody know how and if so could you please tell me my mac is redundant at the moment thank you paulandvonn :cry:

Hold down the "option" key while it's booting (hold they key down until you see the blue screen), and a screen will come up showing you what bootable systems are available. OS X and Classic have separate icons. Click on the one you want, then click on the arrow button.

You can also search for info about Open Firmware Mode, but that's pretty arcane stuff; the boot screen is easier.

As someone else has asked: what problems are you having with OS X? What Mac is it?

Warren.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.