Link Roundup 4/21/22

Slope’s Game Room has a video about the history of Golden Axe.

The Verge’s Ash Parrish writes about a revival of Lucasfilm’s 8-bit virtual world (which is not quite the same thing as a MMORPG) Habitat, something I know a little about I suppose.

Marcus Richert writing for Techradar has a provocative article suggesting that Nintendo might be either slightly younger than the company claims, by a few years, or alternatively might be much older.

Shmuplations translates three interviews from magazines with various people connected with quirky Sega action-puzzle game Chu Chu Rocket.

And Marc Normandin for Paste Magazine has an article suggesting 10 retro games that should be revived, and you know what, it’s actually a pretty great list! It’s got For The Frog The Bell Tolls, Dragon Slayer, and Terranigma on it, so it’s definitely got JRPG cred!

Lemmings on the Apple II

Via 8bitnews.io, Vince Weaver has created a 10-level proof-of-concept of a port of Lemmings to the Apple II family of microcomputers. This would have blown a lot of minds back in 80s elementary school!

The framerate is pretty low, which isn’t uncommon for 8-bit ports of Lemmings, compare it to the Commodore 64 version. Most versions of Lemmings use some kind of hi-res mode on the hardware, and behind the scenes create levels out of large blocks of premade graphics like in a paint program.

Apple II LemmingsProject page

Game Boy Camera Virtual Art Gallery

From Cat Graffam on Twitter, the Game Boy Camera Art Gallery is a Game Boy rom image, in the form of an RPG-style walkaround, showing off photos taken with Nintendo’s crazy and awesome little heavily-dithered, 4-color foray into 90s digital photography. It can be viewed in-browser or as a downloadable rom, or you can purchase a cartridge with it for use on your own Game Boy or Game Boy-compatible hardware! Here are a few works from the compilation:

Nicole Express: Tengen’s NES Chips

The always-wonderful retro gaming and hardware info site Nicole Express has a great post about the chips that Tengen (a subsidiary of Atari) used in their cartridges! Tengen is a special case among NES developers, in that while a Nintendo licensee they got to use their own mapper, from Namco, but went and manufactured their own ASICs when they split off from Nintendo’s licensing program. The deets are all in the article!

Nicole Express’ archives are well worth a look, which among other items hosts their article on Zaxxon and Future Spy. They have interesting games to play on their itch.io page too! Have I used enough exclamation points yet?!

The Hidden Structure of the Overworld of Link’s Awakening

pmorinerie (on Mastodon @pmorinerie@mastodon.xyz) has been working on a full disassembly of the fourth Legend of Zelda game, Link’s Awakening on the Game Boy, and has a series of articles they’ve written about interesting technical aspects they’ve found.

One of their discoveries is of a hidden structure to the overworld of that game. Their discussion of this is fascinating, and should be referred to if you have an interest in such things. I will give a broad summary here.

The Game Boy was not given much VRAM for storing graphics. To avoid bus conflicts, the CPU that runs the system only has access to VRAM, to store new background tile information, either during VBLANK, a specific time each frame when the PPU circuitry isn’t accessing memory, or by blanking the screen entirely, which is only really feasible during major transitions, like through a door or into a hole. So, the system is limited in how quickly it can store new tiles during play.

Link’s Awakening stores two kinds of tiles in its VRAM. Most of them are from a set that’s used throughout the overworld, but a small number are overwritten, used for different purposes as Link explores the landscape. The overworld is separated into 2×2 blocks, and each can have its own set of these customized tiles.

There is a problem with this setup, however. When Link changes screens, like in the original Legend of Zelda and A Link to the Past, the screen transition scrolls smoothly between the areas. During the scroll, briefly, it’s possible for elements from two different screens to be displayed at once. How does the program handle situations where the custom tiles have two different definitions between screens?

The answer is that the overworld is cleverly designed so that there aren’t adjacent screens with walkable passages between them that use different sets of custom tiles. There are screens in the game that only use tiles from the main overworld set, and all of the places with passages between the screens with custom tiles have one of them, as a kind of memory airlock, to prevent glitches during transitions. It’s pretty clever.

If this is interesting to you, I encourage you to read the whole article, especially for the exceptional cases where the system breaks down and they had to find other ways to keep the screen from glitching.