"Blast processing" is a marketing term coined by Sega of America to promote the Sega Genesis as the cooler and more powerful console compared to the Super Nintendo Entertainment System. It was such an effective campaign that it caused Nintendo to spend millions of dollars to ramp up their own smear campaign to rebut the claims, helping to create the textbook example of a "console war" between two rivaling video game companies through aggressive marketing and advertising. It is true that Blast processing as presented in advertisements at the time does not exist in any released Genesis game, but its creation was based on a real, low-level progressive processing method that ultimately went unused by developers in their games.

The basic idea is that the hardware's video processor is "blasted" continuously, with the Genesis' 68000 processor working flat-out to change the color of every individual pixel during an active scan, a process where the "guns" on a CRT screen move from left to right and then down to the next line and so on. It was believed at the time that this function could be used to increase the Genesis' somewhat constrained color palette to showcase 256 color static images if timed right (this number would be exceeded by other developers like Jon Burton from Traveller's Tales who later discovered the trick).

Sega of America senior producer Scott Bayless claimed that technical director Marty Franz first discovered the trick by "hooking the scan line interrupt and firing off a DMA [direct memory access] at just the right time", as firing it off at the wrong time would result in the scan lines appearing out of phase. This timing/synchronization issue, on top of the more pressing issue of the feature using all of the 68000's CPU time (meaning that while you could run the feature, you couldn't actually play the games that use it), effectively made it useless for cartridge games, and no shipped Genesis games ever used it. It’s speculated that it could have been used for Sega CD games, as the add-on had its own CPU that could run the feature, but this also did not come to pass.

The people responsible for the name "Blast processing" are Bayless and Sega of America's PR team. They interviewed him about the specs of the console, and he described to them how the feature could "blast data into the DAC's [digital-to-audio converters]". When talking about how the name came about, Bayless assumed the PR team just liked the word "blast" without understanding what he was explaining, and Blast processing was invented by them to more easily and vaguely sum up the technical capabilities of the Genesis when marketing it. Bayless later expressed reservations about the phrase, calling it "ghastly".

It should also be noted that this feature was apparently not exclusive to the Genesis. In 2020, former Sculptured Software programmer Jeff Peters claimed that they discovered a similar technical trick on the SNES before Sega started using the phrase, but it was focused on audio rather than graphics. He claims that when porting Mortal Kombat to the SNES, Sculptured Software encountered an issue where the amount of graphics data being put onto the cartridge meant that sound had to be cut back drastically. To overcome this problem, Peters and his team used a homegrown system which allowed them to read sounds from the cartridge one at a time and blast them directly to a buffer in the sound memory. While the two tricks were achieving different things, it's interesting to note that both were possible on either console, despite Sega's insistence that only the Genesis could achieve Blast processing.