Migrate or download Ps CS 5 Extended to newer iMac

Update to my progress:

My new 2019 iMac (Intel processor) came with Catalina (With the release of macOS Catalina 32-bit applications are not supported anymore.) See below for Ps CS5 requirments (64 bit). I have Time Machine backups from my crashed 2010 iMac which had Ps CS5 Extended.

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2019 iMac Specs:

Model ID: iMac 19,1

27-inch with 5K Retina display 5120 by 2880 resolution

MacOS 15.3.1 Sequoia 

3.6GHz 8-core Intel Core i9 processor, Turbo boost up to 5 GHz

96 GB 2666MHz DDR4 memory

Radeon Pro Vega 48 with 8GB of HBM2 memory GPU  

2TB SSD internal storage

3- 2TB Seagate Desktop HDD SATA External storage

CD/DVD/Blu-Ray/M-disk External Optical Superdrive

QuickTime: 10.x 

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PHOTOSHOP CS5 EXTENDED SYSTEM REQUIREMENTS (From original box packaging) :

  Upgrade from Adobe Ps CS4, CS3, or CS2. I upgraded from CS2 (have all packaging from CS2)

*64bit: Native 64- and 32bit software. 64-bit processor and OS required for 64 bit version

*Multicore Intel processor; MacOS X v10.5.7 or v10.6 (10.6 Snow Leopard rec'd)

*1GB Ram; 2GB avail.hard disc space (Can't intall on vol. with case sensitive file system or removable flash based strorage system)

*Display (1280x800), OpenGL graphics card, 16-bit color and 256MB of VRAM

*DVD-Rom drive; QuickTime 7.6.2

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I checked Ps CS5 Extended using it's serial number and it comes up saying it is in use and offers a "oval download button" (where-as all the previous listed versions did not). The original Ps CS5 package I bought has the DVD of CS5 included. I checked the Adobe account on a Mac Air(M1,2020) running macOS Monterey, maybe that's why it offers a download? Maybe if I check it on the iMac with Sequoia it won't?

  I've also been told I have to "Deactivate" CS5 before trying to move it, I don't see where that is done, any idea? I'm still pondering what I can do as I wait for a new cable to attach my TimeMachine backup to the new iMac, or try the DVD, or migration Assistant. Can I load it to an external HD by download or DVD and use it only off the open external HD when opened on the display?

Thanks for link Peru Bob-

Apparently I may be able to download it, I put serial number in and my history poped up with Ps CS5 on top with a oval download button, no download option on all the prior earltier versions. I haven't tried it yet, waiting to be sure I have all things in order.

Thanks so much for the reply Jeff-

I have Catalina MacOS 10.15 on the new iMac 2019 27" 5K retina display which haven't plugged in yet(item sat years while overseas job). I read that CS5 would work well on the old Snow Leopard, I have an original Mac OS 8.6 CD. I have a huge 2TB HD and external HD. Would it work to load the OS 8.6 to a separate drive on new iMac that I could use to download CS5 to and open when I want to use it and not the Catalina?

New iMac Specs:

27-inch iMac with Retina 5K display

  With the following configuration:

  3.6GHz 8-core 9th-generation Intel Core i9 processor, Turbo Boost up to 5.0GHz

  8GB 2666MHz DDR4 memory

  Radeon Pro Vega 48 with 8GB of HBM2 memory

  2TB SSD storage

options incl: 3.6GHz i9 8 core ($400); 2TB SSD internal drive ($1100); Radeon Pro Vega 48 GPU Graphics Card ($450); Magic Numeric Keypad ($30);