Posts Tagged ‘assembly’

Done! Well, mostly..

Sunday, December 13th, 2015 12:49 pm

I’ve got all of the base game mechanics done, the goal of the game is to grow your crops, but to do this you need water!  And there is none, so you kill rabbits, and use their blood to water your crops.

I’ll get some final touches done if I can, but I’m pretty drained after all of that assembly..


Emulator troubles.

Sunday, December 13th, 2015 10:21 am

Time is closing in and things aren’t going the way I’d like, having a lot of trouble with emulators as each one gives slightly different results with the game.  Though, I did manage to implement some basic collision, so you can kill the rabbits now.  They also come from both sides of the screen.  Writing a game in z80 assembly has definitely been..interesting, I might do something like this again next LD, it has been fun.

Hopefully only a few things left to implement before I can consider my game mechanics done, after that it’s just any finishing touches if I get time.



Posted by
Sunday, August 23rd, 2015 4:46 am

You work for a shady government organization, that specializes in software and encryption.
One day, the superiors had brought you this machine and only one task: fix it. No questions asked.
But at what cost?


The game will require you to analyze inputs, and guess what kind of actions you have to perform on them, to give the expected outputs.
As you fix the machine, messages from unlocked memory banks pop up, containing a bit more info than some would like to know about what’s it used for…

Will you keep coding?


So yeah, the game’s coming along nicely 😉

Banana Nana (NES game): postmortem

Posted by (twitter: @morphcat)
Sunday, May 3rd, 2015 11:34 am


LD32 has been an amazing experience, we set high goals for ourselves and managed to make something decently playable.

Yes, you read correctly. Banana Nana is an actual NES game. We tested it on the real console and it works perfectly. I had plenty of experience coding basic top-down adventure/RPG engines from scratch in 6502 assembly due to some experimenting last year, so I was confident I could do it. My friend Nicolas exceeded all expectations with the awesome graphics he made, though!


Our game’s hero Nana

What went right

The weekend before, we met to brush up our skills. Without this, we couldn’t have pulled off a game of this scope. dev stream
We were on the Ludum Dare front page for most of the time and got a substantial amount of interested people watching. That sure kept us motivated to make something great. Thank you so much, everyone!

What went wrong

Missing features
The game might be playable, but we didn’t manage to add some of the things we had in mind.
There were supposed to be three gorilla boss fights and more extensive dungeons, but all of this simply wasn’t possible within 72 hours. So we decided to keep the gorilla sprite and reduced the dungeon size to one room each where you just collect a powerup for your weapon, the Bananarang, which allows you to access new areas and advance. We also had to give up the idea of implementing a player status bar.

Gorilla Boss

Gorilla Boss

There were also some bugs, most noticably the Bananarang wrapping around screen edges, allowing speedrunners to reach places that should not be accessible early and finishing the game in less than a minute.

Speedruns (thanks, Magmfur!):
Any% (glitch abuse)


Bananarang Upgrade


Even if it was hard, it’s certainly possible to make an NES Game in 72 hours.
You can watch the development in this time lapse video.

If you like what you’re seeing, why not…

Play and rate our game Banana Nana

Hope you’ll enjoy. :)

We decided to continue working on this game after LD. I might stream future development at
Thanks for reading

NES game for LD32

Posted by (twitter: @morphcat)
Wednesday, April 15th, 2015 10:18 am

Me and my friend are in!

We will create an NES game from scratch. I’ll be writing pure assembly code for the 8-bit 6502 processor, he will provide gorgeous pixel art.

Stream: (starts at 9 am CEST on April 18th)



Special Wondering…

Posted by
Monday, February 9th, 2015 12:24 pm

I know lots of games out there are the following ( c++ c# java python? maybe javascript ) but i wanna take it up a notch and wonder if use 6502 assembly making a game with that instead of the old used stuff. Well I just wanna know if that’s fine. Note if i do. the testers will need an emulator of some sorts to run it :) Thanks for taking the time to reply!


Thank you Sosowski!

Posted by
Sunday, September 29th, 2013 6:35 am

A long time ago I programmed a little on a Commodore 64.

I found programming in assembly hard and being a lazy teenager soon gave up.

Many many years later (just after an unsuccesful Ludum Dare) the Mini Ludum Dare ‘Low Level’ was declared. This REALLY inspired me. I immediately knew I wanted to do something for the Commodore 64.
The next day (after a mind storming sleep) I had a complete idea in my head.
Because I had no idea about design tools for the C64 and not much experience in making sprites I decided to keep it very simple. Here’s  a first sketch I made:

I found out, that the cross assembler I previously used, didn’t work on Windows 7.  I had to look for a new cross-assembler. C64PrgGen looked nice so I used that. Looking back, maybe not the best choice, it had some bugs that really cost me a a lot of time. But after one day I had become reasonably comfortable with it and I got up to speed. For the graphics I settled with making them in Excel. Probably not the best choice, but easy to alter to my own wishes. Here the design for the title. It’s made up of 96 altered characters.

Programming in assembly gave me some challenges, but fewer than expected. Because I kept it simple I didn’t run into memory problems or problems in using too many cycles.

These two books (yes young people, physical books!) helped me a lot with the workings of the C64 and where to map my graphics :



The end result looked like this:

I was very pleased with the result. It took me a week to do, but if you had asked me a year ago if I thought I could make a game in assembly for the C64 in a week, I would have laughed.

So Mr. Sosowski, thank you for this inspiring theme and giving me a chance to redeem myself for my lazy childhood!



(link to the end result)

Game Idea: CLIMB UP!!

Posted by (twitter: @isharacomix)
Friday, August 23rd, 2013 7:44 pm
; In the game of CLIMB UP!!, you want to reach the macguffin at the top of
; the stage. But you don't want to get your hands dirty, so you send your
; lil'dudes to get it for you. Lil'dudes can push blocks around and jump
; pretty high, but have tremendously short lifespans. After 10 seconds, they
; die. But luckily, dead lil'dudes are particularly useful as stepping stones,
; as they can be pushed around and jumped on.
; How many lil'dudes do you have to go through to reach the macguffin?

For this game, I have the following checklist items:

  1. Create a stage loader and draw the stage.
  2. Write game physics (control lil’dudes).
  3. Add game mechanics (death and movable blocks)
  4. Make some basic sprites
  5. Add sound effects
  7. Extra credit: make different lil’dudes with different powers


Let’s get dangerous!

Posted by (twitter: @morphcat)
Thursday, August 22nd, 2013 1:20 am

Hey there, first Ludum Dare for me.

I’ve been into 8-bit console development for a while. While making an actual game on such a console is a time-consuming task, it is tremendously fun and rewarding.

Can a decent NES game be made within 48 hours? I’d like to find out.

Here is what I will be using:

  • Languages: C, Assembly for timing-critical bits
  • Library: Shiru’s NES library
  • Text Editor: Notepad++
  • Art: GraphicsGale, YY-CHR
  • Sound and Music: FamiTracker

While using C instead of pure Assembly makes coding quick, it has two huge drawbacks: slow speed and bulky code. C compilers, at this time, are not able to emit fast and well-optimized code for the NES’s processor (and may never be).

I will try to restrict myself to the NROM cartridge board that most of the earliest NES games used. So, for all you technical buffs out there or anyone coming from modern HLL-coding looking to get their minds blown, these will be the specs the game has to deal with:

  • Processor: 6502 (with no decimal mode), clocked at 1.79 MHz
  • RAM: 2KB
  • 32KB ROM for code and data
  • 8KB ROM for graphics

I might stream development and respond to questions at

EDIT: I should also mention that I am going to use this Makefile which I adapted a bit. It calls some command-line tools I’ve written, mainly for converting VICE label files to the format used by the emulator FCEUX, making debugging easier.

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