VBIOS archive for the Sapphire Radeon HD4870 PCI-E card with 512MB GDDR5 memory. The bracketed 7503600 likely marks the clocks programmed into this image, so compare it to the stock values of your card. Such a file lets a technician restore a corrupted or modded ROM, writing it with ATIFlash under DOS or straight onto the SPI flash using a programmer when the card shows no output. Make sure the memory size and PCB match, and always back up the current ROM contents before flashing a replacement.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @biosarchive. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →