Archive for the ‘Retrochallenge’ Category

So this is the end. The Retrochallenge is over and I couldn’t meet the deadline with a complete working game as I planned and promised.

Although I couldn’t finish the game, I have a very good foundation ready, and if I had about six hours more, I would finish it. That’s too bad to get so close and not be able to complete the challenge, but I am the only to be blamed about it. But I won’t do it, because I will continue to make the game until it is done – maybe I could do it for the Winter Challenge!

In the small video below you can see the game was getting there, and I was able to manage to use Player/Missile techniques with the goalie, player and the ball. Although the ball is the only animated on the video, the plan is to make the goalie to jump to try to catch the ball.

The joystick directions will set the direction the ball will be kicked towards the goal, and the gauge on the bottom right side indicates the precision of you kick – Closer to the centre you click the button, more precise will be the kick.

One of the problems I had to develop the game was that I spent too much time with the math to make the ball go towards the selected point. Although the formula was simple, it took me a while to figure out that the P/M coordinates are different than the ones on the playfield. It was explained on several different places but it slipped from my mind when I was coding that part.

During the next week I will also try to capture and make the source code available here. Stay tuned!


Are you looking for some Commodore 64 technique? Bad timing! We are in the midst of Retrochallenge Summer, and for the month of July I’m all Atari!

Today I managed to draw the playfield, which is going to be a view of the goal area in 3D-ish view:

Playfield almost ready

Playfield almost ready

The first concept that I had to grasp is the Atari colours and how to use them. Atari graphics work with the concept of colour registers, with a total of 5 registers available.  Since I’m using the graphic mode 7(+16), I have four colours available, one background and three colours, so I will use only four of the registers.


It is been a busy week at work leaving no time for the Retro Challenge other than setup the machine and read some books about Atari Graphics. After a lot of thinking I’ve decided what is the game I’m going to make (or die trying!): World Cup Penalties It seems appropriate since we are going towards the World Cup 2014 finals to make a game using that theme. An actual soccer match seemed way too much for a month of BASIC programming, and a 70’s pong-like soccer game would also be too little for my Atari 600xl! With that in mind, I decided to make a Penalties game, where two players alternate between defence and attack which I believe is a doable yet fun game to make.

Too little for the Atari 600XL

Here is my plan: (more…)

I’ve learned few weeks ago about the Retrochallenge that happens every winter and summer, which is , according to its website,  a loosely disorganized gathering of RetroComputing enthusiasts who collectively do stuff with old computers for a month. The challenge will be held from July 1st to 31st.

Excited about it, and with tons of interesting stuff to do but very little will power, I decided to enter this year as a way to motivate myself to do something new retro-wise.

I know this is a Commodore 64 blog, but I am a big fan of all 8-bit machines I can put my hands on, so for this challenge I’ve decided to do something with my latest acquisition: an Atari 600XL! To keep the Commodore lovers under control, I’m calling this challenge the Blasphemy Edition, since I am going to use a less sacred machine. Don’t worry Atari lovers, I’m saying that only to please the Commodore lovers. Don’t worry Commodore lovers, I’m saying that only to please the Atari lovers. Don’t worry….(repeat until you get tired).

Here is my challenge proposal:

– Create a game in BASIC that uses graphics and the player/missile resources. The game will be simple but it has to use those techniques – theme is still TBD (it will be defined before July 1st)
– All the work will be done in the actual Atari 600xl with a cassette tape as storage device. I won’t be using any modern resource like emulators, SD2PC devices, etc.
– I will be blogging the experience in at least a weekly update here under the title “Retrochallenge 2014 – Blasphemy Edition”
– The final result will be made available for download at my new website as soon as I can send the program to my PC (I don’t have the means to do it right now)

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Retrochallenge 2014 website: