Because of a few issues I ran into, here the step by step instructions so you can get started faster:
- Download the .img of your choice from http://tinycorelinux.net/ports.html
- Partition your sd card in Disk Utility into 3 partitions (50MB (Boot), XXX MB (TCE), 250 MB (swap partition))
- Doubleclick the .img file so it gets mounted in disk utility
- Click on restore. Use PiCore as source, the Boot partition on your sd card as target. In 5.3.x, only about 23MB were used. Ignore the free space.
- Eject the sd card, put it in your Pi, start the Pi. No X yet - that part Disk Utility won't do right.
- Create the Linux/TCE partition - see http://tinycorelinux.net/5.x/armv6/releases/5.3/README
steps starting with 1). Use the option "u" to see what you are doing. Ignore the little bit of free room OS X left between the partitions.
- Create the Swap partition using mkswap /dev/mmcblk0p3 (you might want to make it a swap partition first with fdisk)
- Install X - see http://distro.ibiblio.org/tinycorelinux/4.x/armv6/README.txt
steps 3ff. It starts automatically when rebooting (sudo reboot), or by typing startx.
- In X, you can check out available extensions in "Apps". Quit X and use tce as shown above to install what you like. I installed XFE and Netsurf today. Unluckily, installing and uninstalling from X doesn't work for me so far...
- You can set your resolution in X with the Editor. Click open, double click the first item until you are in root, open opt, then bootlocal.sh. See http://distro.ibiblio.org/tinycorelinux/faq.html
F3 boot time options for codes to put into the line vga=7xx.
There might be easier ways to get going, and I'm probably wrong about some of this, but that's what worked for me...
Edit: Found out it's pure chance whether PiCore recognises my Monitor or not after a reboot. Needed a few more reboots to make it work correctly again. My boot options get completely ignored when the system thinks my monitor doesn't support higher resolutions...