A standard ATX (or AT) power supply can be used with an Amiga 1200, so that's an easy route if you have one. Cut off the cables (Amiga PSU donates connector), some electrical tape, and a paper clip to jumpstart the ATX PSU, and Bob's your uncle.
By an incredible stroke of bad luck the first Covid lockdown (the one that lasted months) happened when I was far from my wife and kid. By chance I was in my childhood home (alone).
Out of boredom I started watching YouTube videos about fixing and maintaining old computers. It motivated to go the attic and garage and find all my old computers. Took the battery out of an old Mac. Greased my Commodore 128's 1570 drive. Booted the C128 and checked which floppies were still working.
And quite some still worked: it was a complete and total blast from the past to see the game Commando, with its incredible soundtrack, booting!
I don't know if the A1200 is prone to leaking capacitors or not: if it is send it to someone who can recap for you.
It was really fun to get these old machines back to life: I really encourage you to do it.
I notice now the internal drive of said 2c isn't working and won't boot anything (I could get ADTPro onto a spare floppy without booting anything). I did use it to do the transfer in 2019. I can boot from an external drive with some patching from the monitor program. I suspect the drive either needs heads cleaning or some realignment, but I haven't had more time to try.
Sadly I no longer have my A1200 (or A600). I have a few disks from it still.
I came across an old box of 3.5 discs a few years back that I had stored away since the early 90's. I recovered them using ddrescue to create images using a cheap USB floppy drive.. was great fun.
Edit: I just noticed that they are discussing this very thing a little further down the thread, with lots of concrete options.
You may want to get some kind of removable media for your Amiga, many people use a compact flash card as a hard drive, then use an IDE to CF adapter [1] to attach it to an A600/A1200/A4000. You can format the CF card as a standard Amiga hard drive, then you can remove it and read the Amiga drive on a more modern computer with unadf [2] and you can convert your AMOS source code to readable text with listamos [3]
[1] e.g. https://www.amiga-shop.net/en/Amiga-Hardware/Amiga-classic-h... but I'm not endorsing this specific shop or its products
I think the Amstrad CPC-464 I had, had even more core memories. But this thing was a beast in its day.