a Minecraft computer?

As most of you probably know 

I'm working as a remedial teacher at a upper secondary vocational institution in Helsinki area, Finland. My students are like 15-40 yo. I have just started with gamification and Minecraft as tools. In fact, the more I use Minecraft the more I believe it's a fantastic educational tool. I try to help and come up with challenges to both weak and strong students. 

The finnish educational system offers you to learn a profession in two ways, theoretical (upper secondary school) or practical (upper secondary vocational). The later alternative includes 120 weeks of studies: 90 connects to your profession, 20 are common and 10 weeks are free choices. And within these last 10 weeks I see my chance to use or test Minecraft, CraftStud.io and more.

My students usually study Business Information Technican  (datanom) but I'm also more and more getting ICT Assemblers  (ICT-montör).

My first Minecraft attempt 

3D modelling as blockholm.com and blockbyblock.org because I believe it's an important thing to practice buildning 3D models of something. These students builds a city and their school buildings. This group are last years students and this project will end in April. This first server is a service I rent (hosthorde) and the world is vanilla creative.

My second Minecraft attempt

This time I wanted a server with specific mods so I had one fellow teacher help me put up a server. According to him I now owe him one. According to me he has been able to make a server course much more interesting for our students because instead of install a virtual server they have been able to set up their own Minecraft/Mumble server. This group are first and second years students. They still have to build 3D models but now also practice programing with ComputerCraft and Lua. 

I've gotten this suggestion to have them pass an obstacle course with their turtles...

Third attempt

If this is working so good, could it actually help weak students to better understand math? And yes, so far so good. I have a couple of students that I try Minecraft with, to understand geometry and more. So on my creative vanilla server I have them to do several things, and to each task put a sign like:

"perimeter=12 blocks", "area=16 square blocks" or "volume=60 square blocks"

Units would be the proper thing in English, but in Swedish it's actually "block".

Forth attempt, the upcoming one

Yesterday I got an idea how to put out a challenge to the stronger students because we always have some troubles getting all the free weeks of courses. If they could do something else besides 3D modelling or Lua programming, could I get them do something else connected to their education? And because I thought I had to came up with a valid idea this morning I posted a question in my favourite Google+ group "Minecraft in Education". And I got this playlist: Building a Minecraft Computer Tutorial from awesome Colin Gallagher!

And just to be sure I also tried to reach the Minecraft Education guru (well, sort of) Adam Clarke. And suddenly I was in the middle of a very interesting twitter discussion with both @thecommonpeople and @abrightmoore. Amazing! ...and I'm not the most active twitter person so it was a new experience. Adam gave me this suggestion: Advanced Redstone Computer Tutorial 1: Introduction and also this reddit Ultimategamer32

Well, what I would like to do:

I have three students (16-17yo) that should be out getting work experience, but they didn't get any work place. Instead they're still in school trying to catch up their studies. And as you all know, it's so much more fun to play... I'd like to get control over their gaming, get them back on track and actually learn something. Why don't make them build a computer inside Minecraft? On my vanilla creative server... 

And I had something like this in my mind (and mostly because that's the only clip I've seen).

Little do I know, because the first question I got was this "what kind of computer" and honestly, I don't know. I still don't know. 

You see, I want a challenge for these three Business Information Technican and if that succeed I can get more students do the same thing.

Maybe I should start with a calculator before getting them into a real computer...? Any suggestions?