An update on the SNES preservation project

As you may already know, I've completed the Japanese Super Famicom collection in late 2014.

Since that time I've mostly been focusing on the European collection and also in writing my various emulators, however I have completed work on the most valuable 100 titles already. That leaves about 1,350 titles to go, which is just ... a lot. A whole lot:

Plus I also moved to Japan last year, so I don't currently have access to them anyway.

Given that, I'm going to be delegating the task of scanning these games to the Game Preservation Society instead. I will be lending them my complete set for approximately 2-3 years to complete this task.

The immediate problem we're facing is, "how do we ship this many games to Japan from the US safely and affordably?", and to that aim, I'd love to hear your thoughts and suggestions. Neither myself nor GPS have experience with a set of this volume.

Now then, what will happen with the project there? Unlike my rather amateur…

Updated About Page

Perhaps not terribly interesting, but I spent some time yesterday rewriting my about page to include a retrospective of milestones from 1997 - 2019. It could be interesting to some folks, possibly.

If you'd like you read it, you can find it here: About byuu

Thanks ^-^

Shibuya Scramble

Near Shibuya Station in Tokyo lies the Shibuya Scramble Crossing.

It is said to be the busiest pedestrian crossing intersection in the world, where upwards of 1,000 people cross during each traffic light cycle. It's a beautiful sight, especially at night with all of the towering buildings lit up:

There's lots to do in Shibuya, including what is likely the world's largest remaining CD record store, Tower Records, with a massive eight floors filled with music CDs from every genre you could imagine: both Japanese and imports.

However, it is not for the feint of heart, for folks afraid of crowds. To get there and back typically requires going through Shibuya's train station, where more than 2.4 million people pass through each and every day.

Your bet bet is to avoid rush hour, which in Japan means around 7am-10am, and then 5pm-11pm. Yeah it's a bit longer than an hour. But go during those times and the trains are likely to be filled far beyond maximum capacity. I'…

Mexican Izakaya: Mexican food in Japan

The one cuisine I miss the most here in Japan is good Mexican food. It is unfortunately quite difficult to find good Mexican cuisine here in Tokyo, but if you really search around and don't mind traveling a bit, you can find them!

I recently went out for a meal at Sol Amigo, so I'll share what the experience is like on this side of the planet. Particularly interesting is that this establisment bills itself as a Mexican izakaya. An izakaya is a Japanese-style drinking pub, usually known for having "nomihoudai" (all you can drink beer, highballs, whiskey sours, etc) and often more unique foods. So let's check it out.

You'll find Sol Amigo on a backstreet in Jinbocho, which is in Shin-Ochanomizu. Accessible from the Chiyoda subway line. A small unassuming sign leads you down to the basement where you'll find the restaurant.

Like many restaurants in Japan, smoking is permitted, and most guests will be doing so.

The experience starts off with your classic chip…

Point Cards

Like a lot of countries, Japan has customer loyalty point cards. There are dozens of them here for all the major chains, and you practically need a larger-than-ordinary wallet to hold all of them. Checking out becomes a bit of an annoyance having to fumble for a given store's card, always greeted with "ポイントカードがありますか?" ("do you have a point card?")

The thing that really sets Japan apart, at least compared to where I'm from, is the concept of using the accrued points. Take Yodobashi Camera for example (a shop that sells just about any kind of electronic devices in spite of its name): anything you buy earns you 1/10th the price in points, which equates to giving you a 10% discount (of what you paid on the given item) toward your next purchase.

Sounds great, right? But it's not: they mark up every last item in the store 10% higher than you would find it on Amazon. So you're never actually saving any money, you're just being lured back to the store …

bsnes v112 released

I've posted bsnes v112 now which adds run-ahead support, along with several enhancements.

You can download the new release at

bsnes: Cooperative Threading Serialization and Run-Ahead

I posted a video yesterday explaining and demonstrating the new run-ahead functionality implemented into bsnes.

This turned out to be a very difficult feature to implement on account of bsnes using a cooperative-threaded model of execution that made serialization (save states) non-deterministic.

It took some effort, but I've now implemented a form of deterministic serialization that allows this functionality to work, and I thought it would be useful to write up how this works in the event that any other aspiring emulator developers are considering using cooperative threading but are worried about how to implement save states with them:

Still, it was quite the journey. This seems like an area of computer science that has almost no research behind it, and so I was pretty much on my own in this process.

Not mentioned in the article because it was tied to bsnes specifics, the new run-ahead functionality also required optimizing my emu…

[bsnes] run-ahead explanation and demonstration | byuu


Reflections on Typhoon Hagibis

Japan was recently hit by Typhoon Hagibis, which was equivalent to a category 4 hurricane once it hit landfall. It was said to be the worst storm to hit Japan since 1958.

Being a direct hit to lower Tokyo, Chiba prefecture was hit the hardest. The storm brought in dozens of deaths, localized flooding, and damage to single-family homes. Hundreds of thousands lost power.

Being in Tokyo, the storm hit me as well, so I thought I'd share what the experience was like.

Prior to the storm on Friday, everyone prepared by stocking up on water and essential foods. Most interestingly, I found it completely impossible to find any bread in the city. Every convenience store and grocery store was picked clean. However, I noticed that the tortillas were left untouched, and so I stocked up on those.

Japan's homes are tightly sealed from the outside for power efficiency, and so homes have indoor vents to allow outside air to come in. I'm told that it's best to close these during storms. …

bsnes Frame Advance Input Latency

I wrote an article recently about optimizing input latency in emulators, available here.
This led to a comment about the perceived input latency in Mega Man X using the frame advance functionality in bsnes. In investigating this issue on my Twitch channel yesterday, I discovered there were two separate issues. These issues only affected frame advance, and not latency in standard gameplay, but all the same, I'd like to do a post-mortem on these here today.
Steps to Reproduce Load Mega Man X and get in-game. Pause the emulator. Now hold down the fire key, and keep tapping frame advance. See how many frames it takes Mega Man to shoot.

This was taking four frames, whereas in Snes9X it was taking two.
Issue 1: pause to frame advance transitioning The first issue is that when bsnes was paused and the frame advance key was pressed, the emulator transitioned from pause mode to frame advance mode, but did not actually run a frame. So in effect, nothing happened at all. The user would ordin…