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Bamboo tackles the age-old gamer question: Why did some battery backed-up NES games ask you to hold down the RESET button when you powered down the NES? Thanks to @ijimkoz on Twitter, Tyrel, and Keenan for their help with this video! Check out more at https://theindustriousrabbit.com ReferencesThe best answers I could start working fromhttps://web.archive.org/web/20140906113717/http://board.zsnes.com/phpBB3/viewtopic.php?p=28592, https://gaming.stackexchange.com/questions/267306/why-do-some-versions-of-legend-of-zelda-on-the-nes-have-the-hold-reset-caution, https://gaming.stackexchange.com/a/229861, https://www.reddit.com/r/nes/comments/9xsi98/holding_reset_when_you_turn_the_power_off/, The 6502 and the RESET linehttps://doc.lagout.org/science/0_Computer%20Science/0_Computer%20History/old-hardware/mosTechnology/_dataBooks/1982_MOS_Technology_Data_Catalog.pdf - Straight from Commodore, the manufacturers of the 6502. Page 31 describes the RESET signal in more detail, The NES's RESET button and the CIChttps://forums.nesdev.org/viewtopic.php?t=11517, https://wiki.nesdev.org/w/index.php/CIC_lockout_chip#Overview, NES Schematicshttps://raw.githubusercontent.com/schenkzoola/NES/main/NES-001%20Console/NES-001.pdf - The console, https://raw.githubusercontent.com/schenkzoola/NES/main/Cartridges/NES/NES-NROM-128-03/NES-NROM-128-03.pdf - NROM cartridge w/o RAM, https://github.com/schenkzoola/NES/blob/main/Cartridges/NES/NES-SNROM-02/NES-SNROM-02.pdf - SNROM w/ RAM chip. Note the power inputs (+5V vs/ CR2032) into the cartridge. I think I read it right!, MMC1 and MMC3https://wiki.nesdev.org/w/index.php/MMC1#Hardware - Power fluctuation handling improved with MMC1 over time, https://wiki.nesdev.org/w/index.php/MMC3#PRG_RAM_protect_.28.24A001-.24BFFF.2C_odd.29 - The MMC3 "door knocking scheme", which is PRG RAM protect, Note that this is tough to test in an emulator because the protection facility is not typically implemented - https://wiki.nesdev.org/w/index.php/MMC3#iNES_Mapper_004_and_MMC6, It's also enabled by default on real hardware - https://www.romhacking.net/forum/index.php?topic=22592.msg316850#msg316850, Less than 1/10,000 chance?https://theindustriousrabbit.com/content/2021-10-08-holding-down-reset-when-powering-off-nes/mmc1_bad_data_worksheet.xlsx - The spreadsheet I used to do the calculations. If I missed something let me know!, Batteries don't last foreverhttps://www.polygon.com/nintendo/2016/1/2/10701068/snes-powered-on-20-years-gamesave-data, TexturesHigh Quality Tileable Light Wood Texture 1 by webtreats (https://flickr.com/photos/webtreatsetc/4727355663) - CC-BY 2.0, Seamless Whitewashed Grunge Textures 6 by webtreats (https://flickr.com/photos/webtreatsetc/4902964656) - CC-BY 2.0, MusicInner Sanctum by Kevin MacLeod (https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100196) - CC-BY 3.0, Bit Quest by Kevin MacLeod (https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1500073 - CC-BY 3.0
Ah, so it’s a bit like the whole “Safely Remove Drive” function in Windows.