D64 Image Format

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.

D64 Image Format

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