Romhack Thursday: Doom on a Commodore 64, kinda-sorta

On Romhack Thursdays, we bring you interesting finds from the world of game modifications.

Look at that title and marvel a bit. Doom on a C64! What an idea. How could it even be possible? What an age we live in. It is a time of wonders. Children are our future.

Of course there’s more to it than that. There is a whole class of “retro” game that amounts to implementing the actual game on separate hardware, and using the supposed host platform as a glorified display and input device. That’s what’s going on in this case. Doom is really being run on a Raspberry Pi in a plug-in cartridge on a processor that’s underpowered by modern standards but far outpaces that of even Doom’s base configuration, and is thousands of times more powerful than the Commodore 64 to which it pipes its output.

But there’s still some technical interest in the means. The device that runs it is a “RAD Expansion Unit,” a DIY device that emulates a C64 RAM expansion, and apparently can even take over from the 6510 CPU and drive the system’s hardware directly. It works by writing to the VIC-II video and SID sound chips itself.

There was still a lot of coding work required to make this possible. A C64 has somewhat decent sound hardware, but the VIC-II chip has severe limitations on what it can display. The Raspberry Pi has to take the game’s display and port it, in real-time, to a graphics chip that can only display up to four colors (out of only 16) in each character cell, and that’s by sacrificing half of its horizontal resolution. Doing that on the fly itself is a noteworthy hack.

Could it be possible to run DOOM on a C64 without such assistance? At native resolution, ha ha ha: no. The memory limitations are too grievous, so at the very least you’ll need a RAM expansion.

I’ve mused at times on whether it might be possible if one uses the character screen as a kind of super-low-resolution graphics mode, each 8×8 character block representing either a 2×2 pixel grid (so, a resolution of 80×50) or a single pixel (40×25). Even at such a resolution 60 fps is probably out of the question, for it takes a lot of cycles to change every tile every frame, but maybe at 30 or 20? 15, 12, 10? (60 is divisible by a lot of numbers.) I will leave that question to people who are more current with C64 assembly coding.

Here is a demonstration video:

Doom on C64 – A playable tech demo for the RAD Expansion Unit for Commodore 64/128 (Youtube, 19 minutes) – Github repository

Super Play Magazine’s Top 100 SNES Games

Lists of the best games for various platforms has been a fixture on the internet since it was opened up to the general public. Every big gaming site, those still with us and those gone (R.I.P. Joystiq) feel the urge to make them periodically. After all, they combine several popular article themes: they’re listicles, they’re about video games, and they make definite-seeming yet inherently subjective statements about things that geeks have over-strong opinions about. They’re the ideal hit-getters for pop culture sites really, whether they focus on games or not.

Even in print, these lists weren’t rare things. Super Play Magazine, from the UK, did such a list in April of 1996, which was reproduced in HTML text by the site RVGFanatic in 2010.

Why would such a list interest us now? Well, most of these lists have a strongly US-focused vibe, and the UK had a somewhat different scene than we (me being American) did. So there are a number of very interesting games on the list that generally don’t appear in other places, including a few Japanese ones. And they included SNES Rampart, so I’m automatically kindly disposed to it.

Of particular note, besides Rampart: three Parodius entries, two Micro Machines games, Pop’n Twinbee, Cool Spot, Samurai Spirits, Hebereke’s Popoitto, Spike McFang, SNES Side Pocket, Xandra’s Big Adventure, Pugsley’s Scavanger Hunt, NFL Quarterback, World League Basketball (made by HAL!), The Chaos Engine, Street Racer, Super Smash T.V., Lemmings II: The Tribes (but not Sunsoft’s excellent SNES port of original Lemmings?!), Sensible Soccer, R-Type III, U.N. Squadron, SNES Civilization, Out To Lunch (I hadn’t even heard of this before!), Mickey’s Magical Quest, Cannon Fodder, Plok (the Pickford Bros. rule) and Equinox (also Pickford-made, and also highly underrated).

Super Play Magazine’s Top 100 SNES Video Games (RVGFanantic)

Gamebase 64 is in Trouble

According to this forum post, classic Commodore 64 database and information archive site Gamebase 64 has been stricken by the death of their webmaster Steven Feurer, and unless they can find someone to replace him soon, and likely provide alternate hosting too, their site will follow him into the Great Beyond.

As time passes, these kinds of events will happen more and more often, so please, if you maintain a website, of any kind sure but our remit is games so let’s say game-related site, please take measures to ensure its continuity in the unfortunate event of your passing. And if you can help Gamebase64 out, please consider it?

Bye, bye, Gamebase64?

The Lost Sound Code of Sinistar

Sinistar was a game that had quite an impressive sound design. It borrowed a bunch of its sound effects from earlier Williams games, with which it shared common hardware that was originally design for pinball machines. A cockpit version of Sinistar, of which only around 200 units were made, was the first arcade game to have stereo sound. And of course all versions of the game have the Sinistar’s famous digitized threats and taunts.

While Sinistar’s main program source code was found and made available on Github, the source of the code that drove its sound hardware has long been lost. Youtube user SynaMax has done the best he could at recreating that code, and has made a video talking about the process, the sound design of Sinistar and other early Williams games, and even found unused sounds in the code.

Contained within the code is the revelation that the sound chip that drove the rear speakers in the cockpit version ran slightly different code than contained within the main sound ROM. The data from that version of the game was only dumped this year, meaning that the game running in MAME was somewhat incorrect.

Now that the right version of the chip has been dumped, the cockpit version of Sinistar now sounds properly in MAME. Although this does mean that users running up-to-date MAME have to refresh their romset for this version of the game. Such are the tradeoffs of MAME emulation.

Another revelation of the video was that the parametric sound generators used by Williams arcade games from that time often produced interesting noises if it was fed with random data. Sound programmers sought out different sets of numbers to give them, including by asking passers-by for numbers off the top of their heads and garbage values found in RAM when dev systems were powered up, in order to produce strange sound effects.

Devs using more recent parametric generators like bfxr, LabChrip, ChipTone, sfxia, rFXGen, wafxr and jfxr can produce noises by similar means using those programs’ Mutate or Randomize buttons!

I feel like I should warn however, near the end of the video is mention of a bit of drama concerning the MAME developers, in getting code supporting the change integrated into the software. I’m not weighing in on this, not the least reason being I don’t know enough about it. But I feel like you should know it’s coming, ahead of time, before embarking on the 51-minute journey.

Rescuing the Lost Code and Stereo Sound to Sinistar (Youtube, 51 minutes)

Romhack Thursday: Speculative Super Mario Bros. Prototype Recreation

On Romhack Thursdays, we bring you interesting finds from the world of game modifications.

Some months ago there were the “Gigaleaks,” huge troves of internal Nintendo files and documents that revealed a lot about abandoned projects and the development history of popular games.

There was so much information in them that people are still discovering new details. One thing that was surprisingly overlooked was source code for the version of Super Mario Bros. included in the SNES remake within Super Mario All-Stars. The source contained quite a lot of interesting commented-out lines and other data, that seemed to indicate that it may have been a hacked-up version of the source to the original Super Mario Bros.

A lot (but not all!) of this has been covered on the Prerelease page for Super Mario Bros. on The Cutting Room Floor. You can go read about it there. There resides information on scrapped enemies and objects, weird modes and behaviors of existing objects, and lots of other curiosities.

For the 38th anniversary of the release of Super Mario Bros., Nimaginendo Games made a romhack that seeks to recreate many of these abandoned elements, and shows it off in a Youtube video. The hack can be downloaded from a link in the video’s description, but only for a little while! I should emphasize that it’s not a real prototype, but a speculative recreation based on information from the leaked source. It even has an older version of SMB’s title screen.

Extra! Did you know that an early working English title for Super Mario Bros. was Mario’s Adventure? And Nintendo of America even made a promotional flyer with that name! These images come from Flyer Fever:

Super Mario Bros. Beta/Prototype recreated in 2023 (Youtube, 8 minutes, link to rom in the video’s description)

U Can Beat Video Games Tackles Super Metroid

It’s yet another Youtube video post, but the subject is pretty notable, U Can Beat Video Games at last tackling the highlight of the Metroid series, Super Metroid for SNES, in an epic-length episode. Often big games get split up into multiple parts, but this time the whole game is covered at once. These videos can’t be easy to put together, and I appreciate the effort that goes into them!

As usual UCBVG covers the entire game, including all items and known cheats, and alternate endings. If you’ve ever wondered why GDQ players, hosts and audience ever shout “Kill the animals” or “Save the animals,” the ending to this video should fill in the blanks to an acceptable degree.

U Can Beat Video Games: Super Metroid (3 hours 37 minutes)

PatmanQC on Atari’s Escape From the Planet of the Robot Monsters

Escape From the Plant of the Robot Monsters (I’m just going to call it Escape Etc. from here) is a game I’ve always been curious about.

It’s weird to think now about the time frame of Atari arcade games. 1972 saw Pong; 1979 was Asteroids, signalling a new direction for Atari in arcades; 1984 was Marble Madness, their first post-crash hit; then, 1991 was Street Fighter II and the start of the fighting game craze, forcing Atari to change direction yet again. They would have some hits from there (like Primal Rage and Area 51), but nothing with real cultural staying power until the era of Gauntlet Legends and San Francisco Rush.

Escape Etc. I don’t think did badly, but it wasn’t a huge hit. You can kind of get an idea of the popularity of one of Atari’s arcade games by how many ports it got. APB, for example, Dave Theurer’s last game at Atari, only got Lynx and European home computer ports, while Rampart (John Salwitz and Dave Ralston’s last game, if we’re noting such things) got a ton of ports to lots of platforms. Escape Etc. didn’t even get a Lynx port, although one had been planned.

This isn’t an Arcade Mermaid post, just another link to a Youtube video review. It’s done in an old style, without a lot of flash, but there’s good things about that too, and the information is both interesting and thorough.

More information on Escape Etc. can be found in this post from Vintage Arcade Gal. It’s text!

The History of Escape from the Planet of the Robot Monsters – Arcade documentary (Youtube, 27 minutes)

Romhack(ish) Thursday: 21st Century Roguelike Pac-Man

On Romhack Thursdays, we bring you interesting finds from the world of game modifications.

It’s another romhack post that’s really not a romhack, but kind of pretends to be one. Gridlock’s 21st Century Roguelike Pac-Man (which I’m going to call 21CRPM) at first looks a lot like the arcade classic, but then becomes something really, really different.

It becomes so different that the game it most brings to mind isn’t Pac-Man but Frog Fractions. It keeps piling on the play mechanics, in a way that the game makes apparent is meant to be humorous, but also sort of, kind of works. I mean of course it’s me saying this, 𝖳𝗁𝖾 𝖯𝖾𝗋𝗌𝗈𝗇 𝖶𝗈𝗍 𝖪𝖾𝗉𝗍 𝖡𝖺𝗇𝗀𝗂𝗇𝗀 𝖮𝗇 𝖠𝖻𝗈𝗎𝗍 𝖱𝗈𝗀𝗎𝖾𝗅𝗂𝗄𝖾𝗌, so maybe I just like that sort of thing. Although the way it’s the most like roguelikes, permadeath, making you start completely over after losing, is possibly the weakest part of it. I had to start over a lot.

You start in the middle of the normal Pac-Man board, in a field of dots, and the ghosts roaming around as usual. It’s not exactly like classic Pac-Man; ghosts can catch you much more easily on corners (you’ll get caught this way frequently times before you adjust), and the AI is a little different. The Red monster, Blinky/Shadow/Akabei/Oikake, can actually turn right after coming out of the box, and move up through the paths above it.

Also, eating the Energizers in the corners doesn’t make the ghosts vulnerable. Instead, Pac-Man can shoot the dots he eats at the ghosts to defeat them, and while an Energizer is active his shots are stronger. Pac-Man must be facing into a corridor in order to fire, meaning he must often be running directly towards a ghost before he can shoot it. The Red ghost has the least health, and can often be gunned down even without an Energizer, while the Orange ghost has a lot of health, and usually must be shot while it’s traveling away down a long corridor. Fortunately, he’s not any smarter than he was in the arcade game.

A big difference is the Hunger meter at the side of the screen. It constantly runs down, at an alarming rate, as you play. If it runs completely out, the game ends immediately, regardless of how many lives you have left! You have to make sure to keep tabs on your hunger. And dots and ghosts don’t refill it, only fruit does, and only a bit of it. What Pac-Man can do, however, is save it for later: he has an inventory now, and grabbed fruit go right into it. You press the X button to bring up a menu, and can then pick out the fruit and munch it on down.

If you had to rely on the fruit from the center of the board though you’d starve pretty fast, so now Pac-Man has the ability to plant fruit in the maze. If you plant it, of course, then you can’t eat it, but it doesn’t take long for it to sprout and start generating new fruit of its own. You’ll soon have to start relying on this to survive.

When you clear the board of dots, the monster box opens up and when you go inside you get this screen:

This somewhat sarcastic screen appears to suggest that there’s more to the game than the starting screen. And it’s right.

Once you clear the board of dots, the game doesn’t end. Ooooh no, you’re just getting started. No, the board you start in is the “home” location in a much larger maze, accessed through the tunnels on the sides of the screen. As you explore this maze, new locations will be filled in on a map in the lower-left corner. The borders of this map aren’t the ultimate edges either. This greater map is created anew with each play; sometimes you’ll have tricky situations right near outside the starting board, and sometimes it’ll be fairly easy going. There are ghosts and dots and fruit in these boards too, and sometimes more Energizers, but there are no regeneration boxes. Ghosts you defeat out there turn into eyes, but have no way to turn back into ghosts, and eventually just fly away.

Out there in the maze there’s a lot of weird things to find. Like shops.

And quest givers:

And locked treasure rooms:

And areas of solid stone, and ore, that must be dug through Minecraft-style with a Pick (go into the Tools section of the menu to use it):

And a whole Pokemon-themed area:

And there’s crafting! And you can spend Galaxians you find to enhance stats! And boss ghosts to defeat! And probably more! I keep finding new parts to the game as I play. The game’s itch.io page even claims there’s a final boss to defeat, in the form of an evil version of Pac-Man, but I haven’t found it.

You can save your game, but in roguelike style, your session ends when you do it, and its deleted when you resume. Your game ends either when you run out of lives or your Hunger meter depletes, and both are way too easy to have happen. I find it helps to plant at least one fruit on each screen, but don’t carry around too many: if you’re holding too many things you become “Encumbered” and slow way down!

It’s an enjoyable game, for awhile at least. Pac-Man’s movement speed quickly feel much too slow for exploring the huge over-maze. His movement speed is one of the things you can upgrade by spending Galaxians, but I’ve only just recently even found one of those in the maze, and it was in a locked treasure room. It feels like there’s a lot more to the game than the permadeath feature allows me to see, but I’m still trying.

It is true that, ultimately, 21CRPM is a joke game, and the point is that Pac-Man doesn’t need elaboration upon, and the extra mechanics exist mostly to feel tacked on. There may not even be a real point to them. But neither is there a point to video games in general, and it’s still fun to explore them, for a while.

One of those boss ghosts you can receive a quest to defeat. They take a lot of damage, speed up as you deplete it, and can even fire back at you. You might want to craft a shield before taking one on, out of three Iron Bars (made from ore) and a piece of Wood (bought in a shop or acquired from using the Pick on a tree). You might be able to use a Sword on one, but they break quickly and I haven’t tried it yet.

21st Century Roguelike Pac-Man (itch.io, $0)

The Digital Antiquarian on Rogue and Successors

[EDIT: link fixed, thanks to the Grogpod Roguelike Podcast for pointing it out!]

I’ve been thinking about doing more @Play lately, but in the meantime, please read this mostly nice, lengthy article from The Digital Antiquarian on Rogue and its legacy. I say mostly because there are a few minor points I disagree with. Maybe I’ve played too much of it, but experienced players tend to view vanilla Nethack as maybe a bit too easy. There’s a ton to learn, but once you’ve internalized it all, you come to realize that most situations have counters, and it comes down to knowing what they are, and not pushing your luck too far. Ah! I’ve not said much on Nethack for years now! I should get back to doing that….

A screen of Amiga Rogue, from the linked article

The Digital Antiquarian: Going Rogue

More on the Terribleness of NES Strider’s Programming

A while ago Displaced Gamers, as part of their great Behind The Code series, did a video about how awful NES Strider’s sprite updating was. Arcade Strider was huge hit and outright masterpiece, a great arcade platformer released right before fighting games took over game rooms around the world, but NES Strider was a wretched thing, full of big ideas but with code woefully unable to live up to them. Imagine a puppy trying to do your taxes. It might put up an adorable effort, but it’s just not going to get the job done.

We linked to their last video examining its malformed construction. Well, Strider is the well of crap that keeps on gushing, and so Displaced Gamers has another video on the subject of the flaws in its programming, this time about its player physics. Walking into walls causes Strider Hiryu to shudder in place; jumping beneath a low ceiling causes him to bump his head repeatedly as his jump continues even though there’s no room to ascent; and his infamous “triangle” wall jump is so wonky that it literally requires a frame-perfect input to pull off, and not even the right frame. You have to jump the frame before you contact the wall!

Here is the new video, which explicates the entire cruddy system. It goes into exquisite/excruciating detail, including tracing the code and examining Hiryu’s X and Y coordinates on a frame-by-frame basis. It’s the kind of deep geekery that I just know you love/hate! Enjoy/despair!

The Physics Nightmare and Bizarre Jumping of Strider (NES) – Behind The Code (19 minutes)

Sundry Sunday: Remade Opening to Grim Fandango

Sundry Sunday is our weekly feature of fun gaming culture finds and videos, from across the years and even decades.

Over on Newgrounds, Yespeace1 remade the opening to the classic 3D Lucasarts adventure game Grim Fandango in Blender. They adhered to nearly everything about the original, so don’t expect a tremendous amount of improvement, but when the first version was so great anyway that hardly matters. The Youtube version is linked below, since it’ll embed here cleanly.

Grim Fandango Resurrected, on Youtube and Newgrounds (3 minutes)