sd2snes and MSU-1

The MSU-1 was a software memory controller (mapper) created by byuu for the bsnes/higan emulator to allow for vastly increased storage for SNES software.  The MSU-1 allows for ROMS up to 4GB in size whereas ROMs for the SNES were limited usually to 4MB without extra hardware.  FMV playback became possible due to the DVD-like storage capacity provided by the MSU-1.  In addition to the size increase, the MSU-1 allows for streaming audio in the same format provided by a CD, namely 16-bit uncompressed stereo audio at a 44.1KHz sample rate.  The ill-fated SNES CD-ROM system that Nintendo and Sony collaborated on was not nearly as powerful and would have suffered from noticeable load times.  In this blog post, let's talk about the hardware behind the MSU-1 and some of the more interesting hacks available for it.

Famicom & NES - Simple Tweaks to Restore Audio Balance Levels

Audio balance levels in the NES and Famicom can cause some consternation and official hardware is not always consistent.  Here I will discuss some simple modifications you can do to your console to restore the balance between internal audio channels and internal audio channels and external cartridge audio.

Analogue Nt Mini : Audio Tweaking

The Nt Mini's audio has come under some criticism from such luminaries as the My Life in Gaming channel.  Kevtris has fixed NES audio issues in Jailbreak firmwares v1.0 (MMC5 pulse pitch), v1.3 (audio sweep bug), and v1.8 (crackling static issue).  The excellent MLiG video was using v1.2, so its statements may not hold true for the latest official or jailbroken firmware.  Even so, it is hard to diagnose and fix a problem without being able to define the problem or demonstrate it in a way that would illustrate the problem to the less-technical viewer.  The MLiG video said little more than "We feel that sound might be somewhat further removed from the original hardware experience than any other aspect of the system."  

That MLiG comment is so vague as to suggest that the Nt Mini could be outputting reversed-duty cycle pulse waves like a Famiclone or too low pitched noise as with the NES Classic Edition, which it clearly does not.  Nonetheless, a more articulate critic of kevtris' APU implementation in the Nt Mini and Hi-Def NES Mod is that in certain musical tracks, the triangle and noise channels are too quiet compared to the two pulse channels.  In order to talk about this claim, first we must discuss the mixing levels of NES APU channels.

OPL2/3 Frequency - The 1Hz-ish Difference

The nature of FM Synthesis sound is based on sine waves.  Sine waves create sound by oscillating at a certain frequency and amplitude.  So a sine wave oscillating at a frequency of 440Hz (the pitch) would sound like an A note (A4) hit above the middle C (C4) on the 4th octave of a full 88-key keyboard.  But a sine wave in and of itself is not very interesting musically, so FM synthesis modulates two or more sine waves to create a much more complex sound.  The sine wave's frequency is programmed into the FM Synthesis chip and the modulation of the two frequency, combined with other methods to shape the waveform such as ASDR envelopes, make a sound more complex and realistic than the Programmable Sound Generators that were used in computer and video game music before FM Synthesis became popular in computer music.

Hyperkin's SNES Mouse - A Curious Product out of Left Field

In the middle of 2017, one of the more prominent companies that make retro-video gaming products, Hyperkin, announced a new mouse for the SNES.  The SNES mouse was released with Mario Paint in 1992, and while some other games supported it, it was mainly associated with Mario Paint.  Needless to say this announcement came as something of a surprise, as few people were really clamoring for a replacement SNES mouse.  I was so fascinated by this product that I resolved to obtain one as soon as I could, budget permitting, and review it on this blog.  This Christmas, the budget did permit my acquisition of what Hyperkin calls the "Hyper Click Retro Style Mouse for SNES", so let us proceed to the review.