High Score storage for Legacy Games

Atari 8-bit

FujiNet now has (as of builds after 2022-10-XX) support to temporarily turn on READ/WRITE mode for specific sectors in disk based games. This can be used, to store hi-scores for games that do not natively have support for FujiNet, and is of most use on public servers.

For the Atari 8-bit, it is implemented using three unused bytes in the ATR file format header:

offset from 0	Description
+ 12	Number of sectors to allow read/write (255 max)
+ 13 and +14	Starting sector number (1-65535)

So for example, the game Jumpman.atr can be made high-score enabled, with the following header:

96 02 80 16  80 00 00 00  00 00 00 00  02 BB 02 01

Where, there are two sectors, starting at 0x02bb (sector 699) which can be marked read-write to store score.

As of the current implementation this means that:

• The game must reside on ATR.
• The game can only have one range of sectors marked read-write.