The story of Ports of Call

Do you remember this strategy game? We spoke with two of its creators.

Ports of Call is a game many have a fond relationship with, something we’ve seen during Retrogamingpappa’s somewhat informal (but also completely official) Norwegian Championship for Amiga games, where it did very well against many tough competitors. Several of us at actually thought it would win the whole thing.

En tittelskjerm mange kjenner igjen.
Many will recognise this title screen.

Become a shipping magnate

If you’re not familiar with Ports of Call, or need a brief recap, it is a unique economic strategy game with the theme of transporting goods across the seven seas. You start your own shipping company, buy a ship or two, and then try to find the most lucrative freight contracts while dealing with ongoing costs and random events. The most interesting twist of the game, however, is that you can steer your ships yourself when docking or departing, or when avoiding icebergs or rescuing shipwrecked people. More on those later.

In addition to delivering an exciting combination of action sequences and strategy, Ports of Call has two main features that have helped it achieve cult status: The first is that up to four players can play simultaneously on the same computer, leading to long gaming sessions where friends and acquaintances try to outmaneuver each other as shipping entrepreneurs. The second is the graphics, which were truly impressive when the game debuted back in 1987 and still look great today thanks to meticulous pixel art by one of the great masters in the field – Jim Sachs.

Rolf-Dieter Klein and Martin Ulrich depicted in the game.

The developers met through TV production

Ports of Call was initially created by the German duo Rolf-Dieter Klein and Martin Ulrich. They met through the northern German broadcaster NDR, and the story of how that happened is interesting in itself. Klein had already had a strong interest in computers for many years – his first encounter with technology was back in the late sixties when, as an 11-year-old, he explored a computer system used by his father’s company. A few years later, he created an electronic “computer game” using LED lights and switches. But it was in the eighties that the breakthrough came.

Klein had written a book on how to build your own computer, which NDR took an interest in. Together, they created a 26-part educational series in 1984, guiding viewers through the entire process. The series was accompanied by a kit, and if you bought it and followed along, you would end up with your own computer – a system called the NDR-Klein-Computer. This is where Martin Ulrich came in, as he was the director of the series.

Rolf-Dieter Klein i nyere tid, med en cubesat han designet to datamottakere for. Den er nå i rommet.
Rolf-Dieter Klein in more recent times, with a cubesat that he designed two data receivers for.

The NDR-Klein-Computer project was also featured on the technology-focused TV show ComputerTreff at Bavaria-based BR 3 – a series Klein was involved with for many years and eventually took over in the late nineties. But back to the eighties and the seed for what would become Ports of Call:

«Me and Martin Ulrich worked on the series during the day, and in the evenings we played some Commodore 64 games. The idea of creating a trading game came up then, since Martin knew a lot about the subject and we had seen games like Hansa at the time,» Rolf-Dieter Klein tells

New platform on the market

In 1985, the first Amiga model was launched, bringing with it one of the biggest generational leaps in gaming history. The duo decided to bet on Amiga for their game.

«At that time, 8-bit computers had much poorer graphics, and Amiga was a significant step up due to its graphics capabilities and many other things, which made us feel it was a much better platform to implement our ideas for Ports of Call on,» Klein says.

Development started in 1986 when Amiga was still a relatively untested platform. Since the developers couldn’t connect to the internet to look up information about the machine, they had to experiment a lot to figure out what was possible. But Klein notes that the documentation from Commodore was very solid, and that Amiga generally provided a good development environment by the standards of the time.

Et komplisert spill.
A game with many options.

Ports of Call was a complex game with many different elements, and the duo wanted to make it as realistic as possible. This resulted in many challenges:

«The strategy is based on so many internal factors, we even built a weather simulator into the game, which is difficult to realize. The simulator is based on how real ships behave. It took a lot of time to test the game mechanisms. Many, many weeks. We also had to create an editing tool for the ports and a program to digitize contours taken from maps. Martin also had to travel to London to get information on business terms for shipping to make it realistic – at that time, we didn’t have Google or anything like that.»

Graphics from the USA

With Klein’s technical background, it’s no surprise that he was the programmer while Ulrich became the game designer:

Et av minispilliene.
A mini-game where you have to avoid another ship.

«Martin Ulrich was responsible for the game mechanisms and the economy. I did the programming. Together, we created the initial graphics, but later Jim Sachs came into the picture.»

This happened while the two developers were looking for a publisher for their game. One of the companies that had invested in Amiga in the early years was American Aegis Development, and since the Germans were familiar with some of their products, they got in touch. It was through Aegis that Jim Sachs became involved.

«I was doing some work for Aegis Development when their VP, William Volk, was approached by two German developers, Rolf Dieter-Klein and Martin Ulrich. They had created Ports of Call, and were looking for a publisher. The gameplay was good, but the graphics were pretty dismal,» Sachs tells

He continues:

«Aegis liked the game and was willing to publish it if the graphics could be fixed. I agreed to supply all new graphics. Rolf had the foresight to use the IFF format to store all the pictures, so I could simply substitute my graphics with little or no additional programming required.»

Jim Sachs lagde grafikk for spillet.
Jim Sachs created graphics for the game.

Jim Sachs had already made a name for himself. He was a veteran of the US Air Force who bought a Commodore 64 early in the eighties (because he wanted to find out what this «bits and bytes» thing the kids were talking about was all about) and created a memorable game called Saucer Attack for that platform. Later, he came into contact with the legendary Cinemaware, and he led the graphics team on the groundbreaking game Defender of the Crown.

Sachs didn’t work on Ports of Call entirely alone. His neighbor, Richard La Barre, became fascinated by the work Sachs was doing on the Commodore 64 and later the Amiga. Around the midpoint of the development of Defender of the Crown, La Barre bought his own Amiga. He spent some time studying Sachs during the day and practicing in the evenings, and after a while, he reached a level that made Sachs comfortable involving him in the development of Defender of the Crown. The collaboration continued on Ports of Call:

«When Aegis asked me to rework all the artwork for Ports of Call, Dick helped quite a lot with some of the incidental art. I think he did the picture of the rat for the infestation scene,» Sachs says.

Denne rotta var det Richard La Barre som tegnet, om Sachs husker riktig.
Jim Sachs believes that Richard La Barre drew this rat.

Defender of the Crown and Ports of Call have one notable thing in common: very attractive water surfaces, created using a technique called «color cycling.» This essentially means that parts of the color palette are switched between frames, so, for example, pixels that are light blue in one moment become dark blue in the next. This creates the illusion of movement without the image actually being animated. Sachs explains:

«I spent many days experimenting with different ranges of color cycling, and discovered a lot of interesting effects. I found that just a bit of motion in the background scenes really brought them to life without any animation programming required.»

An example of colour cycling from the title screen. Image from Amiga Graphics Archive, used here with permission.

Trouble with the publisher

For Klein and Ulrich, the collaboration with Sachs worked well:

«After we contacted Aegis, we sent images to them and then to Jim Sachs, and he did everything on his own and made really nice pictures. The game’s presentation is largely influenced by Sachs’ graphics. Otherwise, there were only minor changes including some with the interface after Aegis came into the picture,» Klein tells

Spillboksen. Foto: Rolf-Dieter Klein.
The game box. Photo: Rolf-Dieter Klein.

For those of us who played Ports of Call, it is hard to imagine what the game would have been like without the eye-catching graphics, so the collaboration with Aegis and thus Sachs was undoubtedly very positive for the game itself. But for the developers, it was unfortunately a different story. Aegis had financial problems, and none of the revenues ever reached Klein and Ulrich:

«We never received a single cent from Aegis’s revenues and started a legal process against them. But they went bankrupt before it led to anything,» Klein says.

Fortunately, he had been foresighted here as well:

«All our contracts had a clause that if Ports of Call was no longer being sold or generating revenue, we would automatically get the rights back.»

Thus, they could re-release the game themselves and port it to PC, where it found a new audience. This allowed them to continue to generate income from the game, but according to Klein, it was never enough to live off and continue as full-time game developers.

Popular in Norway

The original game became very popular in our country, and considering how many have heard of it here in Norway compared to how well-known it seems abroad, it appears that we have embraced the game in an almost unique way. When asked if Klein was aware of this, he replied that he had only noticed it to a small extent, but he knew that some of the revenue had come from our part of the world.

Får fortsatt litt panikk av å se dette.
Panic mode!

He believes the main reason players have embraced Ports of Call is that it can be played many times, and you always experience something new. We also wondered if he had received any unexpected feedback from players and were a bit surprised by the answer:

«It was surprising how difficult they found it to rescue shipwrecked people.»

Fortunately for us, this answer meant that we got a chance to ask how to actually do it – we have struggled with this ourselves. Here is the solution:

«You need to drive at roughly the same speed and direction as the raft to rescue them. So the vectors need to match to some extent.»

So now you know! If you need a visual guide, Retrogamingpappa decided to make a video after mastering the technique:

Ports of Call on the road?

Another thing you probably didn’t know is that Ports of Call could have had a sequel focused on trucking. This revelation came via Jim Sachs when he talked about the collaboration with the two Germans:

En senere utgivelse. Foto: Rolf-Dieter Klein.
A later release. Photo: Rolf-Dieter Klein.

«Those guys were easy to deal with, and I’m glad their game did well. Martin came to the U.S. afterward to do research for another similar game based on the trucking industry, but Aegis folded soon afterward and it never happened.»

When we contacted Rolf-Dieter Klein about this, he revealed that this was just one of two games he and Martin Ulrich planned. One was about trucks, and the other about planes. As with Ports of Call, the goal was to build your own company, while the games also had Ports of Call’s simulation elements – in the truck game, for example, you could load and unload goods manually, while the plane-focused game would have difficult routes to fly, and so on.

Unfortunately, we never got to see how these games would have turned out. However, Rolf-Dieter Klein has continued to work on Ports of Call, which exists in several different versions and has received many updates over the years. The work on the series continues to this day, with the latest version being called Ports of Call Deluxe 3D 2024.

«I work on Ports of Call Deluxe in my spare time, and with Steam, I can now reach more people, so I hope to generate some income from it. But there are many games out there, and Ports of Call is a niche product, so it’s hard for me to reach the right buyers.»

You can find Ports of Call Deluxe 3D 2024 on Steam. You can also buy the original MS-DOS PC version on Steam.

Thanks to Rolf-Dieter Klein and Jim Sachs for patiently answering all our questions.

This article was written by Retrogamingpappa and Joachim Froholt.

You can find more content in English here.