The docs for the Ultimate-II+ expansion cartridge for the Commodore 64 state:
It is able to read D64 files, as well as D71 and D81 files (no partitions), T64 files.
So what are D64, T64, D71 and D81 files? Where did they come from?
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Sign up to join this communityThe docs for the Ultimate-II+ expansion cartridge for the Commodore 64 state:
It is able to read D64 files, as well as D71 and D81 files (no partitions), T64 files.
So what are D64, T64, D71 and D81 files? Where did they come from?
These are disk- and tape images files for the Commodore 64 and computers using the same floppy drives and disk formats, like the VIC-20, or the Commodore 128.
The Dxx formats are straightforward sequential dumps of all sectors on a Commodore disk in ascending order, i.e. starting with track 1, sector 0, followed by track 1, sector 1, until the disk "ends" (in the 1541 case) at track 35, sector 16. More detailed documentation on the internal structure, including the structure created by Commodore DOS, can be found here.
According to the German C-64 Wiki, the D64 name was introduced with the C64s emulator by Miha Peternel in 1994, even though disk images with the same structure had been around since the 1980s. Miha Peternel also created the T64 format (see also here).
All of these are common in CBM emulation, and CBM drive emulators. There are more formats, and they are supported by a number of tools.
Since I've been writing code to interact with various systems' disk image formats over the past few weeks I'd like to add a little more information that's not in the current answers.
Disk images and tape images are usually of a few different types and subtypes. I'm using my own terminology here so forgive me if there is standard terminology I'm not yet aware of.
In the case of .d64
, .d71
, and .d81
, they are all "high level" "raw" disk image formats, and are all closely related in the same family. A program implmeneting one can fairly trivially be extended to work with the others.
As for .t64
, it's a "high level" "headered" tape image format which includes quite a bit of structured metadata about the data on the tape.
They are image files that contain the data from cassette tapes (T) and floppy disks (D).