1 The A600 motherboard revision info can be found bottom middle, just left of the trapdoor. This particular mobo is rev 1.5
2 Seen here in the middle is the "Gayle" chip on an Amiga 600 motherboard. The chip handles bus control, floppy, PCMCIA, ATA interfaces etc.
3 The PCMCIA port on the A600. Not a hugely sucessful port on the AMIGA, but there are a handful of useful peripherals that use this port so it's still useful. (For example, its possible to add wireless Network Cards and CD ROM controllers as well as CF card readers and stuff like that...)
4 The "other" Amiga 600 port. This is the trap-door connector but its quite limited and typically just used to expand RAM.
5 Amiga 600 motherboard. There is not a lot of empty space in an A600. Stuff looks crammed before you start removing HDD cradle (removed here), Floppy Drive etc... The Colorful chip with the red ball is an updated ROM chip and the small square chip just above it is the MC68000 CPU. The connector to the left of these two is the PCMCIA port.