SIM CITY
How to become a mayor in a million ... games author Peter Scott reveals all


When I first heard of Sim City almost a year ago from generally ecstatic reviews in the computer press little did I realise how well I was going to come to know it.

I'd just finished converting Hostages by Infogrammes when Superior Software, who'd acquired the rights for the BBC Micro version, asked me if I wanted to program Sim City - I agreed immediately.

It arrived a few days later and my first reaction was shock. It is the first game I'd become truly addicted to in years, and after a fortnight of continuous playing I doubted that such complexity and depth could be squeezed into a BBC Micro or Electron.

And when the 2,500k of Amigo source code arrived I realised I was involved in a massive project.

The original Commodore 64 version was written four years ago by Will Wright of Maxis, under the name Metropolis. I decided not to look at this, but to base the BBC Micro one on the Atari ST and Commodore Amiga versions. These were written more recently, are better presented and have many more features than the original.

Put very simply the game makes you mayor of an area of randomly selected land starting in January 1900. You have £20,000 with which to create a city by zoning land, providing power, roads, mass transit, police cover and so on.

Zoning allocates land for residential, commercial or industrial use which are then used in accordance with demand which constantly changes.

All this costs money which you recoup in the form of local income tax (no poll tax here). If you set the rate too high no one will live in your city, set it too low and you'll run out of money to pay for essential services.

One deliberate departure from "reality" is that in Sim City you can't borrow money - that would be far too easy.

You come across many problems with your city, ranging from traffic congestion to crime, and natural disasters like earthquakes, tornados and alien monsters.

All these factors affect how fast your city will grow or contract, and your score and approval rating. What the people think of you is on a scale of 1000, which is the highest, I've managed 900 in many weeks and months of playtesting. You are given all sorts of statistics to help you along your way:

There's a graph screen that shows a ten year record of six aspects of the city. There's a map which gives you a bird's eye view of the whole landscape, along with the areas covered by police and fire stations. Inadequate cover can lead to big problems with crime and growth.

It all sounds very simple to play - and it is, using only a few keys and an icon/pointer environment. The addictive hook is that every action you take affects everything in the program but not necessarily straight away.

For example, let's say your people are complaining about traffic congestion, you provide more roads, at great cost. This causes pollution which the people also don't like. It's solving this type of dilemma that makes the game so addictive.

The formulae that connect every factor together are vast and complicated - some are pretty obscure too. For example: Putting up a lot of trees reduces the crime rate. Why? Well, if you look at it putting trees in an area make it look more rural, and so more desirable to live in. This pushes up the property values for the area, and places with a high property value are less likely to harbour criminals so the crime rate is lower.

Knowing these facts helps when playing the game, naturally enough, and yet even knowing how each formula is put together there are inexplicable things that can happen - for example, there's usually a recession at the end of the century. This isn't programmed in but is a result of all the factors that make up the simulation. It's very satisfying to see the program taking on a life of its own, seemingly independent of the programmer.

It took six months of intensive work to convert Sim City twice as long as most conversions take. And the 25k memory constraint, above everything else was a constant thorn in my side.

Take working out the power grid: The game has to know how many buildings are and aren't connected to the power stations. The Amiga version uses a 25k buffer to work this out - as much memory as I had in total. The only way I could see to do it was to use the display screen as a buffer and switch all the colours to black in that area using interrupts.

This still wasn't enough and eventually I had to devise a completely original method - the result can often work out the power requirements on an 8 bit Electron faster than the 16 bit Amiga.

The BBC Micro has ended up lacking only the animation of the ST and Amiga versions. This added nothing to the game and could flicker badly on the Amiga so was better omitted anyway. The BBC Micro version has many more features
than the original Commodore 64 one yet is half the size.

Because of its nature Sim City is a game of almost infinite complexity, not only is it an addictive game it's also highly educational. Why is it that a four per cent taxation level in Sim City is so successful, yet most real countries start at 20 per cent?

I can only hope that I've been able to give you a true flavour of the theory behind it, and you enjoy playing it.


Hints on gameplay

Playing the game well requires a lot of initial trial and error, so don't be afraid to scrap a city after you realise that you've been doing something wrong and now know how to correct it.

Here are some basic hints that should make things easier:


This article appeared in the March 1991 edition of the "Micro User", published by Database Publications. 

Scanned in by dllm@usa.net
http://www.stairwaytohell.com