DisplacedGamers

Mega Man 3’s Graphical Glitches, the MMC3 Mapper, and a Bad Development Timeline – Behind the Code

“Is my copy of Mega Man III messed up?” This question is a common one from those that either have not played the third game in the series or are returning to it after a number of years. There is a graphical glitch above Shadow Man in the Stage Select screen. A segment of pixels […]

DisplacedGamers

How to Reprogram Tetris By Playing It – Behind the Code Leveled Up

In a previous episode of Behind the Code, we talked about how the scoring logic of Tetris can crash the game at high levels. Now what is even more interesting is that you can hook up extra controllers to the expansion port on a Famicom and use them to redirect code execution to the A-Type […]

DisplacedGamers

The Wacky Frame Rate and Game Engine of Dr. Jekyll and Mr. Hyde (NES) – Behind the Code: Leveled Up

While I was working on the previous episode of Behind the Code and researching Jekyll’s walking speed in Dr. Jekyll and Mr. Hyde for the NES, I noticed that the frame rate was rather odd. Turns out it is REALLY odd. If you’ve played the game, you may have noticed that the speed is inconsistent. […]

DisplacedGamers

Reprogramming Dr. Jekyll and Mr. Hyde for NES – Behind the Code

A friend of mine rented Dr. Jekyll and Mr. Hyde when it was new, and we gave it a try. It was certainly different than any of the other games we had played on the NES. Try playing Contra or Punch-Out and then switching over to a game that demands patience like this one does. […]

DisplacedGamers

The Physics Nightmare and Bizarre Jumping of Strider (NES) – Behind the Code

NES Strider feels janky. We’ve known that since it was released. But how bad could it be? … Oh! Absolutely terrible! Jumping, running into a wall, and falling – simple things in any other game seem to be half-baked in Strider. The physics are worse than you could possibly imagine. Why do you slam your […]

DisplacedGamers

NES Sprites, OAM, and the Battle for Priority – Behind the Code

Sprite limitations and flicker define what the NES is. They are a part of history. This video dives into Object Attribute Memory – OAM – to explain why the system is limited to eight sprites on a scanline as well as how both sprite limitation and sprite priority are used by programmers to add some […]

DisplacedGamers

Let’s Dive into the Cycles, Speed, and Video Output Timing of the NES – Behind the Code

The NES needs a clock in order to function. Both the CPU and PPU use clock cycles to perform their duties. These chips run at different speeds, but each speed is derived from the same source – a 21.47727 MHz crystal on the NES motherboard. How do these components work in tandem? This video dives […]

DisplacedGamers

MMC2 Magic – How Graphics Work in Punch-Out – Behind the Code

Unique graphics. Giant sprites. No flicker. How on earth does this game work? The MMC2 chip contained in Punch-Out’s cartridge allows the NES to switch between two pairs of tiles for each half of the pattern table. While the MMC1 already allows bank switching for graphics, the MMC2 allows the switch to happen in the […]

DisplacedGamers

How do Boxers Work in Mike Tyson’s Punch-Out!!? – Behind the Code

Punch-Out!! has been on my list of games to investigate for a long time, and I finally have something to show after a crazy amount of research. This video covers how opponent data is used to determine where to branch and what to do in code, how to manipulate boxer behavior, secrets that you will […]

DisplacedGamers

How Speedrunners BROKE Castlevania’s Scrolling – Behind the Code

In December of 2019 after many years of runs, the speedrunning record for Castlevania on the NES was close to 11 minutes 24 seconds. In Summer of 2020, speedrunners took a new discovery for the implementation of scrolling for the game and used it to skip several screens at a time in various places throughout […]