Interview with the creator of “Pulse” [Vic-20]: Sven Michael Klose

Hi, welcome back 8-bit friends! Today we speak directly to the developer that created the super-fast game “Pulse” for the Vic-20: Sven Michael Klose.

The releases of “Pulse” are available for unexpanded machines up to 16K (i.e. you can use any kind of classic Vic-20 memory configuration). For example if you use the memory expansion you get some digitized speech and a scoreboard with music.

To play and support this awesome release you can get your copy here:

As you begin the game you can immediately experiment its incredible smooth scrolling and admire all those fast shots, enemies and levels, in hires and multi-color graphics, in such a little amount of memory. Sven Michael Klose with no doubt knows how to make great games for the beloved Vic!

By the way: it seems that the best score is something around 4k points, can you do better? If so, then send us your screenshot!

For sure in this game you have so many shots that you can take care of yourself in enemy territory!



One last thing before the interview: just remember that his new game Arukanoido is going to be released the 1st of September and the final game version will be covered here as well, in the next days. For info about pre-orders just see the details at Denial to contact the author. In the meantime you can take a look at Arukanoido preview #5.



Q – When did you start coding with the Vic-20 and why do you still code on it?

A – Hi there! I started my first experiments in BASIC on my first VIC in 1985 when I was 10 years old but I had to carry on with an Amstrad CPC very soon afterwards. The real start with the VIC, the 6502 CPU and game programming was in January 2014 and the result was “Pulse”. Now I’m still coding for it because I was told that I’d be kind of good at it, because the VIC is still unexplored territory and the community around it is awesome. I’m sure we’ll see lots of stuff that was considered impossible to do in the future. Adrian “beamrider” Fox just came up with smooth scrolling in all directions without borders for
example. Such things give me incredible kicks.

Q –  Do you prefer a real machine or an emulator? Or how do you combine the two?

A – For development? The VICE emulator. It’s super-accurate. If you find something that does not work on VICE you must be on to something novel. Developing on the real thing would literally be a waste of time.

Q – Which memory configuration do you prefer for development?

A – In the beginning I preferred unexpanded machines but now I go with the flow. Am trying to keep the memory requirements down but with more memory it’s easier to get things working at all. And then there’s the Ultimem expansion that opens up a whole new dimension with 1MB RAM.

Q – How much does it take for you to code and release a new game? How do you approach the process?

A – With “Pulse” I just wanted to be left alone and do something I’ve never done before. The tiny memory space took off the burden of making decisions. Things fell into place. For the next idea I just asked a friend what was her favourite game and that provided a blueprint. Then it’s about implementing things in small steps picking tasks that don’t require thinking. Usually I commit the problem solving to the back of my head and wait until it’s finished.

Q –  Which other programming languages do you like, in general?

A – Lisp. If you ever heard that learning to code in Lisp would make you a better coder for the rest of your life even if you won’t be using it: that’s true. PHP makes me feel like a newborn: covered in blood and screaming. I use any language that’ll help getting the job done even if I went to a party the night before.

Q – Which tool-chain do you prefer when developing for the Vic?

A – A bunch of terminal windows with the VIM editor on Linux I can switch back and forth between and I ended up writing my own 6502 assembler in Lisp in order to be able to automate things.

Q –  Which parts do you like the most (and which the least) while developing a new game?

A – Things that go for programming in general: the best is if you have to ask someone if you can have your computer back. The worst is if life is a mess and there’s no quiet place to get a workflow and you want to hire The Sopranos to beat the crap out of those who interrupt your attempts to survive every five minutes. Had far too much of the latter recently until I couldn’t tell shit from chocolate ice cream anymore. Am still in the process of recovery.

Q –  One suggestion to new coders who want to develop on the Vic-20! How should they start?

A – If you’re new to programming better learn programming on modern machines first. JavaScript is a good pick. In my experience plotting pixels on the HTML canvas element excites newcomers and gives them a feel for bytes, address space and essential algorithms. If you can code already grab the Programmer’s Reference Manual and join the VIC Denial community. On Windows I’ve heard CBM PRG Studio would be awesome but I never used Windows.
On Linux or any other Unix the ‘xa’ assembler will get you started quickly.

Q – What about your next release?

A – That would be “Arukanoido” – a clone of the famous arcade game Arkanoid, hopefully available on tape the 1st of September. One can find out everything about it on the VIC Denial forum and grab a demo there. But be aware that nothing has been optimised yet.

Q – Thanks a lot for the interview and for contributing to keep alive the “little” gem Vic-20! Please feel free to add your greetings and comments, thanks!

A – My pleasure. I guess it’s time to greet Feline Lang and Christoph Klemke of the band “Feline & Strange” in Berlin who provided me with a van full of Christoph’s retro hardware last year. Please visit their site and get your ears boxed – they provide their awesome music for free under the Creative Commons license.



-NonSolo8Bit © 2017


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