Search for the most precious substance in the universe


Who thought it was unobtainium?

Riemannian is a text-based space adventure game written in BASIC. I am not certain of its origins but it was converted to BBC BASIC by Janny Looyenga (and I think it was released as either a Beebug, or an Acorn User magazine disk).

I have just spent my afternoon converting it to run on the Raspberry Pi under RISC OS and subsequently on the PC under BBC BASIC for Windows.

In Riemannian, you control a spacecraft, which teleports randomly around a text-based Teletext universe. You have three resources that need to be managed: oxygen, fuel and provisions. Your quest requires you to mine as much of the elusive riemannian ore before your resources run out and you are unceremoniously dumped back to the BASIC prompt.

On your journey, you will encounter aliens, both friend and foe. Some will wish to sell you commodities, whilst others try to blow you away with their laser guns and robot slaves. There are also some other special encounters, but I wouldn't want to spoil your fun of encountering these yourself.

This world is very notable for the Uslian tree ant and its inhabitants' exceptional loathing of sit coms

I have covered how to convert BBC microcomputer programs to RISC OS BASIC programs in another post.

The main problem I had to overcome is the fact that, in Riemannian, much of the gameplay is time-based. You have to press the right key at just the right time to zap an alien or mine the planetoids. Upon inspection of the code, two facts became obvious. Firstly, the code was a horrible mess of spaghetti (probably indicating that it originated on a less elegant 8-bit machine to the BBC micro) and second, much of the timing revolved around how many loops the computer could perform whilst waiting for your input. As my target machine, the Raspberry Pi, is a much faster machine, I had to alter these timing loops so the original gameplay was restored. I think I have managed whilst also making the game a little more forgiving than the original.

From a time when mining was much more about guesswork (just like modern Fracking).

+1 Geek Experience Point awarded to by Janny Looyenga for the original BBC BASIC conversion.

I am going to assume that due to its age, Riemannian is currently in the public domain. So you can download a copy from my OneDrive. If you are the owner of Riemannian, and it is your sole source of income, then I am really sorry and I will remove this link as soon as you get in touch.

I've provided four versions:

  • A RISC OS BASIC file
  • A plain text file containing all the code
  • A BBC BASIC for Windows file
  • A Windows executable file (it is totally NOT a virus, but if you are in doubt run it in a sandbox such as Virtual Box rather than trusting a strange blogger on the Internet).

If you enjoyed this post, then that is it, you have reached the very bottom of the Web, but you might like some other conversions of ancient BASIC programs, such as this one, or this one, but especially this one.

That's it for today. I will be back later for more geeky stuff - stay tuned!