An interview with Dave Semmens

Dave Semmens worked on a large variety of Amiga games, programming them all himself except for the game Rainbow Warriors which had a team of 3 programmers. His Amiga softography consists of the following games:

Can you give me a little background information about how you got into the industry?

I always wanted to work on games. My first computer was a ZX81 and I was far more interested in creating games than playing them. I moved from the ZX81 to a Commodore 64 but really wanted to learn and use Z80 rather than 6502 so swapped it for a ZX Spectrum! :)

I spent lots of hours in my bedroom working on sprite routines and some simple sound routines. I had recently left school and was on an apprenticeship to be an electrician when a friend spotted an advert in the Yorkshire Post for games programmers and I decided to apply. The job was for Source.

The interview went well and I was offered the job there and then - my first game was to be an 8-way directional scrolling Gauntlet type game called Bushido Warrior.

I went home and wondered what I had let myself in for as the game required 8-way directional scrolling and lots of baddies running around on screen at once. Not something the Spectrum was really built for.

I finished the game and Source was paid for the work but the game was never released due to the publisher (Ariolasoft) going bust. This was a real shame as it was a good game.

Over the next few years I worked on more Spectrum and Amstrad conversions and then moved on to the ST and Amiga as more work started to filter through for it.

Did you quit at some point and become a freelancer, or did Source close down?

I left after around 3 to 4 years to become a freelancer. I kept getting approached by different companies and the thought of working from home (and not travelling 60+ miles every day) did appeal to me. So I got my first mortgage while still employed and then went freelance a few months later.

Rainbow Warriors

Can you please tell me what parts of the game you wrote? (The game lists Adrian Scotney, Ian Richards and yourself working on it).

From memory (it was a while ago) I wrote 2 of the mini game sections and may have done the frontend to the game (not 100% sure on that).

The mini games were both breakout type games that involved revealing a picture. I remember both games playing well and been very addictive. I was sad that one of them could only be played once the other levels had been completed as it was very good to play and I am sure you are aware that 90% of players complete the first level but only probably 10% get through to the last level - so my hard work would only be seen by a few players.

Spellfire the Sorceror

For your next game you seemed to jump ship to Codemasters. How did that come about?

Codemasters wanted a lot of their 8 bit back catalogue moving over onto Amiga/ST so they offered the work out on a payment/royalty basis. I had some time so decided it would be a good idea to do a conversion for them. I had already written Wizard Willy for them on the Spectrum/Amstrad so had contacts at Codemasters. Spellfire is the Amiga/ST version of Wizard Willy. You must understand - I did not come up with the names ;)

Was Spellfire made before SAS Combat Simulator? (Presumably you knocked one off, they were satisfied so gave you another conversion to do aswell?)

I honestly cannot remember.

If you were paid royalties for the Codemasters games, can you remember approximate sales figures? Some old Amiga magazines from the 1980s suggested budget games were happy to sell around 5,000 copies which seems awfully low, does that sound about right?

I know I never made much money on them - that is why I only did a couple of conversions.

SAS Combat Simulator

I'm curious to know how the conversion process worked. Were you given source code from the 8-bit versions and left to your own devices, or just had to watch and play the game to duplicate it?

I never had source code - just a copy of the game. I would play it and get a feel for it. My artist would do the same and then we would put the game together.

Did you have to create an identical version for both the Amiga and ST version?

Yes - identical versions for both Amiga and ST. The Amiga versions would not use any of the hardware or blitter - it was quicker to use code that would work on both machines and they still ran at a reasonable speed.

Can you recall how long they took to convert?

I think each game would take a month or so to put together and the code would run on both machines at the same time with minimum changes.

Did you read reviews of your games and if so, were you annoyed when the games received low scores? (Here's the Amiga Format review for SAS Combat Simulator as well as the C+VG review).

If the game was a conversion then I had very little control over how it played - so I didn't really get too frustrated. On one occasion when working on a Game Gear game (Dragon - The Bruce Lee story) I spent a long time writing a software sprite routine so that the usual glitching sprites did not occur. Every review I read of other Game Gear games mentioned glitchy sprites but the reviewers didn't mention the amazing fact that Dragon did not glitch. All that hard work and not even a mention.

Kid Gloves 2

Who came up with the original idea for the game?

I played Super Wonderland on the ST and really enjoyed it (I very rarely played games). I thought it would be great to write a game that followed the same structure so came up with the platformer.

The game was originally scheduled for release in mid-1991 as Little Beau, but was eventually published by Millennium in early 1992 as Kid Gloves II: The Journey Back. Can you explain what happened?

Digital Magic showed interest in the game and I finished the coding ready for a release. Unfortunately they went bust just before release, but Millennium stepped in and showed interest.

Did Millennium insist on the name change?

I think the name change was to try and gain more sales on the back of the original Kid Gloves - the game was not written as a sequel to it.

A demo of the game was released on an Amiga Action magazine coverdisk. Did you get paid anything or was it purely for publicity and to help sales?

I don't remember getting any more money for the work - it was all free publicity :)

Was it another game that required an ST port?

Yes - no hardware acceleration on the Amiga.

The Incredible Crash Test Dummies

It seems that around 1991 a lot of programmers began to utilise the Amiga hardware properly, especially with regards to re-using sprites for status panels and other overlays. Several of your games also used them including Crash Test Dummies. Did this came about as the ST began to die off?

I think that the Amiga owners were content with any game to start with but once they saw what the machine was capable of (due to games such as Shadow of the Beast etc.) they wanted more bang for their buck. At that point more people moved towards the Amiga and the ST slowly faded away.

This game came out on the Amiga, SNES and Megadrive. Did you work on any of the other versions or just the Amiga?

I only worked on the Amiga version.

Which was the lead version if any, or was this another conversion job?

Just another conversion - I think I worked from video footage of the game but cannot remember 100%.

The credits in the Amiga version show:

Coded by Dave Semmens.

Graphics by Doug Townsley.

Map conversion by Steve Burrows.

Artwork and design Matty Walker.

I'm guessing that Doug worked on the Amiga graphics, but did Matty Walker also work on the Amiga version of game or just did box artwork or something?

No idea â€“ he was not involved in any of the Amiga in game art.

What exactly did the map conversion entail as it would seem to me that changing a map from one machine to another would be a pretty trivial task!

I cannot really remember but Steve and Doug lived close together so it was easy for them to both work together if any graphic type conversion work needed doing.

With a larger team on this game did you have to have more face-to-face meetings or were you still able to work on the game at home?

I still worked from home.

The Lion King

What was the development system you used to create the game?

I used a system called PDS (Programmer Development System). This allowed the programmer to develop the code on a PC then assemble (compile) and download to the target computer (Spectrum, Amstrad, C64, ST or Amiga). If the target machine crashed then you still had everything safe on the PC and it also allowed real-time debugging as the software ran on the target computer.

How long did you have to write the game, and was there any kind of deadline required to cash in on the Christmas sale period?

The game had to be released in time for Xmas and I had around 2 months to get the work done.

Can you explain the overall process of converting the game from the Megadrive? Did you have the full source code or had to observe the game and duplicate it?

When I took the work on I had agreed with the publisher that I would receive all the source code from the Mega Drive version. This was the only way that I expected to be able to complete the work in time. I had expected it to be in 68000 (the Amiga and Mega Drive shared the same 68000 processor) and thought that a lot of the game logic and baddie control could be lifted straight from the existing code.

When I received the code it was in a language that I had never seen before - it turned out to be C. All my work up to that point had been in assembler (6502, Z80 and 68000) - I had no idea what C was and it was a major problem at that point in the development. In the end I only used one table from the source code provided - the table that controlled when the wildebeest came on and what position they ran from in the stampede level.

Were you able to re-use a game engine from any of your previous titles for Lion King or did you have to start from scratch?

I had quite a few routines built up already from previous games. All the main areas such as control, sound, sprites etc.

Did you have the maps for all the levels already provided to you or did someone have to redo them from component graphics blocks?

I had an artist (Doug Townsley) rework the graphics for the Amiga. I already had some mapping tools that he could use for putting the block sets together.

Did the map use 16x16 pixel blocks? Were the multiple layers used by the game all using the same block size?

Yes, the map was built up from 16x16 pixel blocks. Everything in the background was derived from an 8-bit map (numbers from 0 to 255) that referenced a 16x16 block.

How did you handle Simba following the contour lines of the terrain? Was it accurate to the pixel level or an illusion?

All the sprites that we had supplied animated around a single pixel that was drawn into every sprite (in bright white). This pixel was the connection to the floor. Every 16x16 block had a separate map file that held 16 bytes. Each of these bytes told the character how far into the block the character had to sink or climb. So it was just a case of finding which block the animation point was over and then finding how many pixels into the block it was. Picking up the offset from the block map and offsetting the character by that amount. This gave the illusion that the character would run up slopes etc. Not sure if my description is clear but it was the simplest approach I could come up with.

How many colours were the original graphics? (eg. if sprites had their own 16 colour palettes on the megadrive was it something like 128 colours down to 32 for the Amiga?)

I cannot remember - this was Doug's department. He did his magic and made them all work on the Amiga :-)

Who was responsible for creating the palettes for each level? Did they change during the level at certain points or were static?

Again - this was Doug.

From some brief analysis it appears to be an AGA dual playfield game (2 playfields of 4 bitplanes giving 16 + 16 colours) + I guess hardware sprites for the energy bars at the top, Simba character, and the life counter? Is that correct? If so, were all sprites 64 pixels wide?

I normally used hardware sprites for the main character and any status parts. I cannot remember if that was the case for this game though. It was a long time ago and my head is still reeling from describing how the slopes worked ;)

Was the screen setup the standard copper-split method, hardware scrolling horizontally and a copper split at some point down the screen resetting the bitplane pointers?

I think at least one of the levels used the copper to split the background parallax. This level is the Graveyard (I think). It limits the background scrolling to just left/right while the foreground moves in all directions. The other levels use full all-directional parallax. Most games on the Amiga cheated by either limiting the background level to wrap - whatever goes off the right hand side of the screen comes back on at the left after a short period. This allowed the programmers to only have to update the foreground map with new info scrolling on from the sides. Lion King has a true multi directional scroll - the background is a map in its own right and new info comes on as you move around. Harder to achieve but much nicer on the eye :)

In certain places, Simba moves behind some of the scenery, particularly on the elephant graveyard level. Since Simba himself is a sprite, how did you get around the parallax limitations of the Amiga to achieve this effect?

I honestly cannot remember.

The game seems to drop a frame regularly during fast scrolling moments. Did you consider keeping the game running at a consistent slower frame rate instead or were you happy with smoothness most of the time and accept the odd slowdown?

I cannot remember slow down but it could have happened. I always thought it best to run at full speed as most of the game was fine. I am not sure if anyone ran this game on a NTSC A1200 - that may have suffered more as it had slightly less time available in the frame.

Did you use the blitter for all the drawing or is the CPU doing some of the graphics donkey-work too?

Yes - the blitter was used whenever possible but it was worth using the CPU at times as well just to get as much horse power out of the machine as possible. Any large transfers of data would have been handled by the blitter.

Did you have any problems running out of memory or it fit into the 2Mb chip easily?

My original work on computer games was on the 8 bit systems (Spectrum, Amstrad etc.) so I very rarely ran out of space on the ST or Amiga. I think the old 8 bit programmers considered memory usage first and foremost as they had suffered so much from it in the past :)

Can you explain a little of the BASIC-like interpreter you implemented to handle the baddies? How did that work?



I cannot remember exactly how this worked. In a couple of games I had a basic language to control platforms etc. This would allow baddies and platforms to be scripted or to hold and wait for specific things to happen (the player standing on a platform for example).

This made it far easier to script the levels, fine-tune and reuse behaviour across multiple types of item.

Was there ever any regard to how many disks you were allowed to ship the game on?



I don't remember having a limit set.

The following levels were left out of the Amiga version:

Both bonus stages (Timon & Pumbaa)

Can't Wait to be King

Hakuna Matata

Simba's Return

Some rumours and magazine news articles suggested they were removed due to lack of disk space, while others say it was purely to get the game out by Xmas. Which is accurate?

I had very little time to get the game done and when it became clear that the source code for the Megadrive version was in 'C' then it was just too big a push to get the game fully completed for a Xmas release. I had 2 of the other levels almost complete but there wasn't enough time to fully test them before release.

There is no real end sequence - just the title shot of Simba on the hill, then a small pause and the credits appear. Was this another case of running out of time to do a proper end sequence, or was the Megadrive version also like that?

I can't remember how the Megadrive version ended - either way we had run out of time so it would have been a hard push to get anything more in.

How much involvement/interference did you get from Disney with regards to quality control? Did they force you to change anything?

I don't remember any problems. We used the original graphics as the source so it was just a case of doing as little to change them as possible.

Did you enjoy working on the game or was it a crunch job from the start?

It was a crunch right from the start. I remember working 40 hours straight at one point (it was big news at the time that a junior doctor had worked 30 hours straight and died). I spent many hours locked away in my little room with no real idea what time of day it was. I would come out for a drink and realise the family had gone to bed and it was 3am!

Have you got any idea about the sales figures for the game?

I wasn't on a royalty and have no idea how well it sold. I lost out on about 25% of my money for not delivering the missing levels but with the time I had to do the work and the lack of 68000 code it was just too much of a push.

Hopefully these questions bring back some happy memories!

I really loved working on games back then - I don't want it to sound as though I hated it! :)

The work was hard but the rewards were very good and there aren't many jobs that will stretch your brain as much as being a single developer on a complex game.

Wrapping up...

Are you still working in the industry today?

The freelance work dried up when publishers decided that they wanted large teams to work on projects. I spent around 10 years working for Acclaim and Sony but due to the nature of the industry I found myself made redundant on three occasions (when the studios I worked at closed down). The last redundancy was the final straw and I decided I needed to find something more secure.

I have been out of games for around 8 years now - I moved away from programming whilst at Sony and moved into team management. I worked as a Producer, Senior Producer and finally Development Director at Acclaim Cheltenham. This made the transition into Project Management quite easy so I took a role outside the industry with a company in Sheffield. I have worked for that company for over 7 years now (longer than I ever stopped at any games company).

I still do some coding but it is in MS Excel, Project and Word.

I work normal hours now and don't have to worry about long crunch periods. I still miss the team pulling together in the final stages of a game though - I have had some great times and would not have missed a minute of it.

Thank you very much for your time Dave!