I want to get one thing straight before we continue: “Blast processing,” as a term, was almost entirely a marketing ploy by SEGA. Yes, there was an actual process that spawned the phrase, but “blast processing” really was just a term that marketing used to sum up that, on a hardware level, the Sega Genesis was just faster.
As for the originating process, that was simply the ability to “blast” data to the video processor at any time. This was utilized to as simple an effect as the water levels in the mainline Sonic games to the more complex FMV intro to Sonic 3D Blast on the Sega Genesis. This could have been used to get full 256 colors on the SEGA Genesis, in theory, but storage space and processing power limited that. An idea was that the Sega CD could have utilized this feature as it contains its own separate CPU, but it was never actually done.
Now, a developer who worked on the SNES at Sculptured Software has come forward with a story about how his team had come up with a process they had dubbed “blast processing” as well. In a book written by David L. Craddock which was published in September 2019, developer Jeff Peters recounts how, while porting Mortal Kombat, he had come across a method of “blasting” sound files directly from the cartridge to the game scene via the sound buffer. Converting from the arcade version of the game was problematic because they had large amounts of graphics data. Storage space was a commodity when developing for home console cartridges and the visuals were the primary focus for the game, so this meant audio had to be cut instead. This is where their own version of “blast processing” came in as they were able to maintain higher quality sound clips for voiceovers and still be able to have more sound sample options during a fight or for a particular level.
So, in the end, the processes were not quite the same, though they do share the commonality of essentially dumping data directly to their respective processors rather than going through their “traditional” processes. This is fairly indicative of the era in game development, however. The limitations of the systems of the SNES era generally meant that developers had to do things outside of the “specs” in order to get the performance they wanted out of the hardware. While the specifics and use-cases for the Genesis’s “blast processing” capabilities have been fairly well documented, largely due to the contributions of GameHut, this particular tech trick was not known to be widely used and is even still somewhat vague in its benefits. Hopefully, one day we will get a more in-depth dive into the technique and maybe learn that other developers came to the same technique on their own as well.
