OS3.9 and OS4.0 in the same Amiga...

[flaviosr]

Hi,

is it possible to have OS3.9 and OS4.0 in the same Amiga with a boot selector?

Thank you

[Thomas]

Yes.

[bigmac]

Wow that was a prety succinct answer Thomas, would you mind explaining how we could acheive this and what boot selector method works best.
cheers
  :-D

[doctorq]

@bigmac

Make two bootable partitions, and use the early boot menu for starters.

[motorollin]

IIRC AmigaKit are also working on a boot menu to allow you to more easily select which OS you want to boot.

--
moto

[flaviosr]

doctorq wrote:
@bigmac

Make two bootable partitions, and use the early boot menu for starters.

Does not work! I disable DH0 (OS3.9) leaving only from DH1 (OS4.0) on but the Amiga hangs! If I remove the boot flag in HDToolBox OS4.0 starts!
Suggestions...?

[zipper]

You have to tinker with boot priorities and boot from early startup screen to be sure that you get not the wrong patch loaded before the real startup happens. I have no problems with 3.9 and 4.0 lurking on different partitions.

[flaviosr]

zipper wrote:
You have to tinker with boot priorities and boot from early startup screen to be sure that you get not the wrong patch loaded before the real startup happens. I have no problems with 3.9 and 4.0 lurking on different partitions.

I have a boot priority of 0 for DH0 (OS3.9) and DH1 (OS4.0) and 5 for DF0... which priorities do you have?

[rkauer]

@Flavio

 That's the very same thing as my A600: I can choose to boot in 2.1 or 3.1 (3.9 on an A600 is an overkill: it will run over and kill my 600).

 On HDToolBox, click on your preferred boot partition and modify the priority. Leave the preferred as +1 and press enter. Save the settings and reboot.

 Next time the system will boot with it. If you want to run the other, reset the machine while pushing the two mouse buttons and select the boot device. Nothing more.

[zipper]

I have a boot priority of 0 for DH0 (OS3.9) and DH1 (OS4.0) and 5 for DF0... which priorities do you have?

Don't remember exactly, but it depends on what you want to be the default behaviour. I think 4.0 is now higher than 3.9 so probably 1 against 0. If they are the same, the boot order depends of the partition names I think.

[countzero]

os 4 needs to run setpatch and start again. so be sure to catch the second boot and disable dh0 again.

an easier method is to give a higher priority to os 4. this way it will directly boot to ps4 without any problems. for os 3.9, you need to enter boot menu and select dh0 for boot device. but remember, if you have romupdate patches in your setpatch, it will restart, so you need to catch it and select dh0 again.

I have a 3.9 rom in my system, so I skip romupdates, which boots to 3.9 without any restart.

[orange]

hm, maybe there is a small util that would set the priority for second boot?

[Ianoakley]

I've cheated a bit on this by installing a hard drive caddy in my tower so I've got OS3.9 and OS4.0 on separate hard drives and it's just a case of slotting in the appropriate hard drive - so no need to open up your case.

The boot selector seems a good idea but from other responses has it's issues.

[Dwyloc]

I think the best option would be if someone created a nice GUI util that allows you to swap the boot priority back and forward between which partition you wish to boot from.

That way you could click on your OS3.1, OS3.9 or OS4 partition as your default boot partition then ether click a reboot button or reboot manually.

That way when reboots for setpatch, IDEFIX etc would not be a problem.

Then next time you want to change with AmigaOS you want to boot you would just run the util again and click on a different bootable partition.

[flaviosr]

countzero wrote:
os 4 needs to run setpatch and start again. so be sure to catch the second boot and disable dh0 again.

an easier method is to give a higher priority to os 4. this way it will directly boot to ps4 without any problems. for os 3.9, you need to enter boot menu and select dh0 for boot device. but remember, if you have romupdate patches in your setpatch, it will restart, so you need to catch it and select dh0 again.

I have a 3.9 rom in my system, so I skip romupdates, which boots to 3.9 without any restart.

I have modified so that now I have DH0, priority 0 (OS3.9) and DH1, priority 1 (OS4.0).
OS4.0 is ok but, when I disable DH1, OS3.9 does not start!
The Amiga asks me for a floppy in DF0!!! Really strange.
I have OS3.9 plain right now (I am still in a WIP. Base installation + IDEFix + Picasso96 + MUI...