:lol: Three answers, all different and none really helpful to someone who has not touched an Amiga in 16 years.
tridion, it really depends on what you plan on doing with your A600, but here are some facts to consider.
An unexpanded A600 has 1mb RAM and runs a 7mHz CPU speed. In that configuration it is not much use except to play classic Amiga games and run some early productivity programs that are not too RAM hungry, Final Copy, or ProWrite comes to mind for word processing, D-Paint III for paint and simple animations (not sure if D-Paint IV, or V would run well on only 1mb RAM).
A600 accelerator boards are hard to come by and expensive.
You can probably fit all the classic Amiga programs you are likely to want to use on a 1gb HD, so a cheap 2gb, or 4gb drive partitioned into two 2gb partitions should satisfy your needs indefinitely. Keeping partitions to a maximum of 2gb will keep you out of trouble with any of the Amiga OSes and file systems (IIRC).
I hope this info is helpful. If on the other hand you are just asking the question to get a technical answer about the absolute limits of Amiga hardware and software, see the other answers and guess which one is more correct.
:-D
As for patches, they are probably referring to additional code that is installed to alter the original Amiga OS so it can handle larger HDs and file, or partition sizes than was possible with AmigaOS 1.3, 2.04, 3.1, etc. Some of those patches are included in AmigaOS 3.5 and 3.9, which was the last official AmigaOS released. Your A600 probably has the 2.04, 2.05, or 3.0 Kickstart ROM inside of it. To run OS 3.5 and 3.9 you will need to upgrade the ROM to the 3.1 Kickstart ROM which was the last Kickstart commercially produced by Amiga.