[NEED HELP QUICK] Headless mini boot menu

[lilabila]

Hi,

I have a headless mini (no monitor) which unfortunately has 2 partitions now and the default startup disk is set to the wrong disk.

The disk I need to boot in is: SSD (10.8 installed)
The disk which is booted into right now is: SSDNEW (10.9 installed)

I've got a keyboard connected to it. After booting with alt key pressed, I tried several methods like: left key, then enter; right key then enter...
Unfortunately nothing seems to work.

Can anybody help me to decide what keystrokes i have to press to be able to boot into SSD?

Thanks

 

[simsaladimbamba]

Is there any chance, screen sharing is enabled in 10.9?
Is there any chance of connecting a monitor to it?

 

[lilabila]

Screen sharing is enabled only in 10.8 (not the default disk)
No, unfortunately a monitor is not available. that's the main reason I'm seeking help in this forum now.

 

[simsaladimbamba]

Do you know, if ALL CONTROLS is enabled in the Keyboard > Shortcuts preferences in OS X 10.9 Mavericks?
I just ask in order to give you the right key commands to enable screen sharing in OS X 10.9 Mavericks in order for you to connect to it via another Mac to change the Startup Disk in System Preferences.
Does the OS X 10.9 Mavericks installation login automatically or does it stop at the login screen?

 

[lilabila]

Thank you very much for your quick help, simsaladimbamba. I appreciate that very much. I'm sorry for not making it clearer at first (It was because I thought it was of no importance), but:
10.9 is in the process of installing itself on the disk SSDNEW in the moment. It is not actually installed yet.
I got into this mess because I made a new partition put the install mavericks app on it and began the installation to SSDNEW. After the first reboot I got where I am now... I know, that's so stupid

 

[simsaladimbamba]

Thank you very much for your quick help, simsaladimbamba. I appreciate that very much. I'm sorry for not making it clearer at first (It was because I thought it was of no importance), but:
10.9 is in the process of installing itself on the disk SSDNEW in the moment. It is not actually installed yet.
I got into this mess because I made a new partition put the install mavericks app on it and began the installation to SSDNEW. After the first reboot I got where I am now... I know, that's so stupid

Hmm, now I am a bit flabbergasted.
Maybe you have now three startup volumes, the OS X 10.8 Mountain Lion, the installer for OS X 10.9 Mavericks and an incomplete OS X 10.9 Mavericks installation.
Normally it would suffice to press and hold OPTION a bit right after the startup chime and then use the arrow keys to go left and press ENTER, but if that does not work in your case, it might be due to a password prompt before that selection.
Have you enabled a firmware password? Have you any chance (neighbour, friend, colleague) to connect a monitor to the Mac to see, what is going on there?

 

[niteflyr]

Certainly you must have a television you can connect it to.

 

[jbarley]

What I've done in the past when I needed a one time access to a piece of hardware, is go to a store that advertises a "no questions asked 15 day return policy".
Get where I'm heading with this?
This has worked well for me on several occasions.

 

[lilabila]

Ok guys, I see, a monitor is needed. Thank you all for your help!