I am a fan of the people who build their own computers from MSI components.
I discovered microprocessors around 1980, when I was 14 years old, but here in little Belgium I was never able to do something with that knowledge at that time, but my interest got me a bachelors degree in electronics, and a good (better) understanding on how software works. I was always interested in FPGA, but it is only since 2010-2012 that I got finally a possibility to do more than programming. I got my master degree in electronics, and on the way I learned VHDL (one of the reasons that I wanted to go for my master degree), and got an interesting school assignment about on the fly reconfigurable hardware and a thesis involving the Spartan-6 Atlys board.
Also, since 2004 I have been working on and off studying Common Lisp, and processor emulators.
Well, since September 2012 I have been designing a simple microprocessor, for which I first did the implementation of an assembler in Common Lisp, and a simulator, and start of this September I finally got around implementing the simple computer system in VHDL. I was surprised how easy it was, given that I only have about 1 to 2 hours a day in the evening to work on things. It is currently a 16-bit thing which uses 64kB of FPGA block RAM.
Thus, with software knowledge and VHDL, it should become even easier to build custom microprocessors.
And I am not even crossing this line. It has always interested me to go for both hard- and software, but due to circumstances I ended up more on the side of software.
Having the room for doing electronics properly is not that easy. One needs a place committed to it, which can not be used by other people in the family. For that reason, I like the concept of FPGA development boards. It lets me do what I want to, without needing to invest in dedicated space.
The Atlys board gives me all I need for growing in the future. The first part should be to make the system run using the on-board serial controller, so that I can control it through a terminal program, having access to a keyboard and a character terminal.
And I am not done with software, because one of my goals is to write a Lisp system for running on the system, and then start to optimize the ISA for better performance. Other things: go to a 32-bit implementation and start using the on-board 128 MB RAM memory.