GRAM Karte format

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The GRAM format is a headered ROM dump format from the cartridge memory chips, introduced by Mechatronic in West-Germany.

The contents of these files are taken from the ROMs and GROMs of the cartridge, so there must be meta-data about the origin of the data. In fact, these files are commonly 8198 bytes long, that is, 6 bytes plus the common size of a ROM (8K).

0 1 2 3 4 5 6 7
0x00 Type Address Length Data
0x08 Data
...
end

Type

  • A5A5 indicates a GROM file
  • 5A5A indicates a ROM file


Address

  • For GROM it is the start address where data is loaded from
  • For ROM it is a bank access address (>6000 - ROM >6000, >6002 - ROM >7000 bank 2, >6004 - ROM >7000 bank 3)

Length

This word specifies the length of data. File size should be the sum of the header size (6 bytes) plus the length of data. If the file is larger, only the given length of data is used.

Other Headered Dump File Formats