Then I will describe and link to my database which contains the most accurate and up to date information for the NES and Famicom ROMs most people care about.Ī Brief Overview of NES Cartridge Hardware In this blog article I will explain how headers work, why they are necessary, the need for accurate information in them and how they have evolved over time. The NES and Famicom w designed to handle cartridges which contained two ROM chips. The first, called the Program ROM (PRG-ROM) contained all the code, data and music for the game. The PRG-ROM was connected to the CPU bus and the CPU could normally address 32KiB of PRG-ROM at a time. The second, called the Character ROM (CHR-ROM) contained the graphical tiles used by the game to display its graphics. CHR-ROM is connected to the PPU bus and the PPU can normally address 8KiB of CHR-ROM at a time. (1KiB = 1024 bytes) That was considered "the limit" and the Famicom Disk System was introduced to help overcome those memory limits.Ĭartridges had many advantages over the disks, and cartridge development continued to overcome the memory limitations.Īt the time the Famicom was released, the memory system could support up to 32KiB of PRG-ROM and 8KiB of CHR-ROM. The NES never received the disk system, so by 1985 the 32KiB/8KiB limit was a straitjacket for larger games and greater innovation. Memory mapping schemes were introduced to allow the NES to transfer or bankswitch portions of ROM to its CPU and PPU. At first the schemes tended to rely on off-the-shelf logic chips to allow for simple PRG-ROM or CHR-ROM bankswitching (or both).
#Studybox nes code#
Some of these methods allowed a game to use only a larger PRG-ROM chip whose code would instruct the CPU to copy graphics data from it into an 8KiB Character RAM chip (CHR-RAM) connected to the PPU bus.īy 1987, the NES and Famicom were sufficiently profitable for companies to develop specialized ASIC chips, like the Nintendo MMC and Konami VRC series of chips, to address far more memory than ever thought possible in 1983. With these advanced memory mapper chips came the ability to add extra RAM, called PRG-RAM, for the CPU to use.
Please note that Milieudefensie has concealed names for security reasons.The NES only has 2KiB of RAM for its CPU to store data, variables and its stack, so some games needed an extra 8KiB for their data. SCS Global Services kindly provided detailed feedback to the draft case study and where relevant, we integrated their comments (for example in the Safacam chapter on the public summary report).
#Studybox nes verification#
Verification was done with crosschecking other resource persons, desk study and documents provided by the local resource persons. The objective was to document their experience and perception of the RSPO consultation. Research was conducted in december 2020 and januari 2021 and is based on just over 50 semi-structured interviews (bilateral and group discussions) with rights-holders and other stakeholders in the Socfin plantation areas. The case study box in the report 'Palm Oil Certification: Not 'Out of the Woods' (page 21 - 25) is a summary of findings from this research. SCS Global Services kindly provided detailed feedback to the draft case study.
In our report 'Palm Oil Certification: Not 'Out of the Woods', various gaps in RSPO standards, guidance and practice relevant to the consultation process have been identified.
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