Module Simulator format

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The GRAM format is a headered ROM dump format from the cartridge memory chips, used by the Modul Simulator of Texas Instruments.

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 8202 bytes long, that is, 10 bytes for header information plus the common size of a ROM (8K).

0 1 2 3 4 5 6 7
0x00 Sign GRMWA Address
0x08 Length Data
0x10 Data
...
end

Sign

Two words with values of >424D, >4D57 (as ASCII text: 'BMMW')

GRMWA

Address of the 'Port' for Port-based memory addressing to where the GROM-Address in the Address field is written.

Address

Address of the location in the GROM address space.

Length

This word specifies the length of data, a maximum of 8k bytes (>2000 bytes). File size should be the sum of the header size (10 bytes) plus the length of data. If the file is larger, only the given length of data is used.

Other Headered Dump File Formats