Is it possible to use Snow Leopard on Mountain Lion iMac with Virtualbox ?

Question

I've been lucky recently, with people giving the perfect solutions for me so I try again.
But, this one is a tough one: How to run a virtual Snow Leopard on a new iMac ?
I got a 2013 iMac with Mountain Lion (10.8.5 now) so,  totally incompatible with Snow Leopard. I need SL anyway.
Give up all you old applications and buy new ones is not acceptable. First, this is not my way of thinking and, second, some cannot be replaced.
Many posts say that you can use Snow Leopard with VirtualBox but I could not find anywhere the "how to" (in this particular configuration).
For instance, I followed these 2 protocols, almost similar:
http://www.maketecheasier.com/install-mac-os-x-snow-leopard-in-virtualbox-on-win dows/
http://www.macbreaker.com/2012/02/snow-leopard-virtualbox.html
but they use Windows as host system and something is not working (for me) with Mountain Lion.
I made many attempts, with VirtualBox 4.2.18, using pretty much everything: Snow Leopard DVD, SL Server DVD, .dmg of both. I've also got Combo 10.6.8 updates for both (but I'm not sure if it can be used before installing). With another MacBook, I managed to install a SLS on external hard drive and update to 10.6.8. Was unable to use it anyway.
Inevitably, I ended up with the message:
"FATAL: No bootable medium found! System halted."
I have no idea of what support to use and even, probably  important, if it should be set on Primary or Secondary Master ? (in Settings / Storage)
Is it possible at all ???
Would it work better with VMware Fusion ? Anybody successful ?
Help
Thanx

Answer 1

How to install and run OS 10.6 Snow Leopard on a virtual machine on top of OS 10.7 Lion:
http://osxdaily.com/2011/11/17/install-run-mac-os-x-10-6-snow-leopard-in-virtual -machine-on-lion/
From kappy:
Clean Install of Snow Leopard
     1. Boot the computer using the Snow Leopard Installer Disc.  Insert the disc into the
         optical drive and restart the computer.  After the chime press and hold down the
         "C" key.  Release the key when you see a small spinning gear appear below the
         dark gray Apple logo.
     2. After the installer loads select your language and click on the Continue
         button. When the menu bar appears select Disk Utility from the Utilities menu.
         After DU loads select the hard drive entry from the left side list (mfgr.'s ID and drive
         size.)  Click on the Partition tab in the DU main window.  Set the number of
         partitions to one (1) from the Partitions drop down menu, set the format type to Mac
         OS Extended (Journaled, if supported), then click on the Partition button.
     3. When the formatting has completed quit DU and return to the installer.  Proceed
         with the OS X installation and follow the directions included with the installer.
     4.  When the installation has completed your computer will require a restart after
         which you will be running a fresh install of OS X.  You can now begin the update
         process by opening Software Update and installing all recommended updates to
         bring your installation current.
First you will have to prep your new SSD:
Drive Partition and Format
1. Boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button.  When the menu bar appears select Disk Utility from the Utilities menu.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area.  If it does not say "Verified" then the drive is failing or has failed and will need replacing.  SMART info will not be reported  on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.