Can't Get My 2016 iMac to start up in OSX 10.6.2

[pflower]

I have an old (late 2016) 27 inch iMac which I normally keep running with Mojave in order to use various programs not supported by later models.  It works fine.

But I also have an old Polaroid Sprintscan 120 which I prefer to use to scan negatives than  with a camera.  In the past I have successfully used this with a cloned external disk with the Silverfast software to run it under OSX 10.6.2. It is cumbersome and requires a bit of cable juggling but it has - up to now  - worked.  But now the iMac (not talking about the Silverfast software or the scanner)  won't boot up from any of the 3 external disks which have 10.6.2 on them.  If I go to System Preferences/Startup Disk the Mac recognises the external drive(s) as having 10.6.2 and allows me to restart with them.  Similarly if I restart the iMac holding down the option key.  I get the usual chime but then it just reverts to a grey screen with the Apple logo and nothing happens.  This is weird since in November 2022 I spent several days scanning lots of negatives using the same system - i.e. bootable disk with 10.6.2 and the Silverfast software without any problems.

Now my iMac won't boot up with any of the disks I created for this purpose.  Nothing has changed as regards the iMac but it just won't recognise and startup from any of the disks that worked perfectly (alright with a bit of a hope and prayer) a few months ago.  I have reset PRAM etc. but no boot up.

Any thoughts from anyone?

[kers]

Usually cannot start up from an older system than the system it came with when you bought it.
In this case a 2015-2017 imac came with system 10.11 or 10.12...
the reason is simple; 2015 hardware is not supported in an operating system that was built in 2007...
https://everymac.com/systems/apple/imac/specs/imac-core-i5-2.3-21-inch-aluminum-mid-2017-specs.html
( almost at the bottom the information)

What you can do is spend little money on an older computer to run silverfast- now is a good time since they are still around and very cheap.
then also buy some extra old memorym (RAM) and it will work fine.
I have the same problem with some of my printers and have dedicated computers to run them

[pflower]

Ah.  That might make sense.  I certainly could use 10.6.2 on this computer in the past but then I may have upgraded the native operating system to Mojave.  Possibly that explains the problem.

So now I need to find a cheap laptop or iMac that will run 10.6.2.  Any thoughts as to what I should look for?

Philip

[langier]

Another alternate that I use to scan into my MacPro running Mojave with my Epson 4990 and CoolScan 8000 is VueScan. Price was lots less than Silverfast though Silverfast has lots of good features.

If your system once ran 10.6x, Snow Leopard, you may be able to create a start-up drive with a fresh install dedicated to your scanner.

Otherwise, take a look at what computer came out at the same time as 10.6x, Snow Leopard, which I think my MacPro shipped with though I don't use it any more. Pretty sure I left 10.6.8 the last version of Snow Leopard on one of my SSDs in the case so I can start things up to use older software as I transitioned to a newer, larger SSD and newer hardware under the hood. I haven't had use the older start-up drive for many years and now mainly use the drive as a cache for Photoshop since there's plenty of room on it. It's also a fail-safe in case my newer start-up fails.

I hate to have to give up my older systems as they fit well like broken-in shoes, but time marches on and some of the newer software features are getting too exciting and useful to want to box my self in.

One colleague a few years ago was happy with his cameras, software, computer and just bought new-old stock of his current computer, took it out of the box, loaded the software, made sure it all worked and put it away for when his current system bricked.

Though I have a slightly-newer MacPro that I'm using now, it's time to move along and hope that I can find a dongle to bring my scanners along. Otherwise, like my MacG5, I'll just add another box under the desk and and hook up my monitors, drives and input devices leaving the other system in place for the legacy peripherals.

[BobShaw]

I have a 2020 iMac running Monterey and run VMware Fusion on it. That allows me to run 10.6, 10.11 and 10.14 all as windows under it. I run a version of Dreamweaver I got in 2001 plus a stack of other 32 bit programmes.