D64 Image Format

CBM DOS as a single image for Emulators
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The .D64 disk image format follows the format as defined for CBM DOS. Images of this format can be used in Emulators like VICE and the PI1541 attached to a real C64.

As stated in Physical Layout, Track numbers start from 1 but Sectors in a track start from 0.

35 track images are exactly 174848 bytes long whilst a 40 track image is exactly 196608 bytes.

The table below shows the position of the start of each 256 byte sector within the .D64 file.

Track Sector Sectors In D64 Offset Track Sector Sectors In D64 Offset
1 21 0 0x00000 21 19 414 0x19E00
2 21 21 0x01500 22 19 433 0x1B100
3 21 42 0x02A00 23 19 452 0x1C400
4 21 63 0x03F00 24 19 471 0x1D700
5 21 84 0x05400 25 18 490 0x1EA00
6 21 105 0x06900 26 18 508 0x1FC00
7 21 126 0x07E00 27 18 526 0x20E00
8 21 147 0x09300 28 18 544 0x22000
9 21 168 0x0A800 29 18 562 0x23200
10 21 189 0x0BD00 30 18 580 0x24400
11 21 210 0x0D200 31 17 598 0x25600
12 21 231 0x0E700 32 17 615 0x26700
13 21 252 0x0FC00 33 17 632 0x27800
14 21 273 0x11100 34 17 649 0x28900
15 21 294 0x12600 35 17 666 0x29A00
16 21 315 0x13B00 36* 17 683 0x2AB00
17 21 336 0x15000 37* 17 700 0x2BC00
18† 19 357 0x16500 38* 17 717 0x2CD00
19 19 376 0x17800 39* 17 734 0x2DE00
20 19 395 0x18B00 40* 17 751 0x2EF00

† Track 18 is reserved for the Directory and Block Allocation Map.
* Track's 36…40 are only available on 40 track images.

Last modified November 1, 2021: Add D64 image format, move entire section out of kernal as it's not specific to it (ee252da)