On this machine, things are a bit easier now. Even if one is found in the trash and locked down by somebody mean with secure-boot enabled and locked out passwords.
I pulled mine out of the closet, and here is the way *I* did it. Minute details lacking, but I don't think you need them.
Make a Ventoy disk. Copy the TinyCorePure64.iso to it.
https://www.ventoy.net/en/index.htmlI took advantage of the micro-sd card slot and put Ventoy and TC on this as the drive to boot from. Other than that, we're not going to write to it, and use a regular usb-drive to store our data. Since it only comes with two usb ports, you may have to invest in a passive usb hub to hold extra stuff like the data drive. And a 3rd party wifi dongle. Or 3rd party audio dongle. But for basic computing, this should suffice.
Ventoy may balk at trying to write to a micro-sd, so I fooled it by using a usb<>micro-usb dongle for the Ventoy install. Then with power off, I placed the bootable micro-sd into the slot. NOT the cooling slot just above it!
From inside the tinycorepure64 iso, locate the cde directory. Copy that cde directory and all of it's contents to the root directory of your new usb stick to act as the data drive. RENAME that directory that you just copied from cde to tce
TIP: It is best to do this with the power DISconnected at first.
Power on the box. At the bios splash, hit DEL to make sure that you change the boot sequence to what now appears as a "UEFI HDD". That's what a micro-sd card that is bootable (at least with Ventoy) is recognized as. Save and exit the bios.
When Ventoy passes to TC's own grub boot menu, you'll most likely want to use "tcw" which indicates an internal waitusb function.
Note that here, you can also add your own specialized kernel boot parameters by using grub's "e" to edit the kernel paramater boot line. A little prior TC-fu goes a long way here. Example: although TC *should* automatically detect the tce directory placed in the root of your usb drive, you may want to make absolutely sure by changing the "cde" to "tce=sda".
This is about the only major drawback to using Ventoy with an iso in this manner. There is no way to *permanantly* edit your kernel parameter boot line, so if you are doing something special, you'll have to do it every time you boot. OR, for more advanced users, change and remaster the iso itself.
Anyway, if you just do nothing and hit tcw, it should come right up.
That's the gist of it anyway. Ventoy's ability to handle not only very modern uefi weirdness, and even Secure-Boot if that has been locked in, is pretty cool. I'm not absolutely sure, but I think they use Fedora's keys if you need to enroll them.
Most of these machines are probably left with the default of secure-boot already disabled anyway, but it's good to know that it can be overcome with Ventoy should that need arise.
Let your TC journey begin!