D64 (.d64)

.d64 file signature | application/octet-stream

D64 is a disk image format for Commodore 64 floppy disks, originally created for Commodore systems and now preserved by the retrocomputing community. It is used to archive disk contents, distribute software and games, and load data in emulators or on compatible hardware. As a legacy format, it is generally safe to inspect, though files from untrusted sources may contain corrupted or intentionally modified disk images.

Safe

Magic Bytes

Offset 0


              A0 32 41 A0 A0 A0

Sources: Wikipedia

Extension

.d64

MIME Type

application/octet-stream

Byte Offset

Risk Level

Safe

Validation Code

How to validate .d64 files in Python

Python

def is_d64(file_path: str) -> bool:
    """Check if file is a valid D64 by magic bytes."""
    signature = bytes([0xA0, 0x32, 0x41, 0xA0, 0xA0, 0xA0])
    with open(file_path, "rb") as f:
        return f.read(6) == signature

How to validate .d64 files in Node.js

Node.js

function isD64(buffer: Buffer): boolean {
  const signature = Buffer.from([0xA0, 0x32, 0x41, 0xA0, 0xA0, 0xA0]);
  return buffer.subarray(0, 6).equals(signature);
}

How to validate .d64 files in Go

func IsD64(data []byte) bool {
    signature := []byte{0xA0, 0x32, 0x41, 0xA0, 0xA0, 0xA0}
    if len(data) < 6 {
        return false
    }
    return bytes.Equal(data[:6], signature)
}

API Endpoint

GET /api/v1/d64


              curl https://filesignature.org/api/v1/d64

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .d64 file?

A .d64 file is identified by the magic bytes A0 32 41 A0 A0 A0 at byte offset 0. D64 is a disk image format for Commodore 64 floppy disks, originally created for Commodore systems and now preserved by the retrocomputing community. It is used to archive disk contents, distribute software and games, and load data in emulators or on compatible hardware. As a legacy format, it is generally safe to inspect, though files from untrusted sources may contain corrupted or intentionally modified disk images.

What are the magic bytes for .d64 files?

The magic bytes for D64 files are A0 32 41 A0 A0 A0 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .d64 file?

To validate a .d64 file, read the first bytes of the file and compare them against the known magic bytes (A0 32 41 A0 A0 A0) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .d64 files?

There is no officially registered MIME type for .d64 files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .d64 files?

D64 (.d64) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.