D81
application/octet-stream
Magic Bytes
Offset: 0
A0 33 44 A0 A0
D81 is a disk image format developed by Commodore Business Machines for the Commodore 1581 3.5-inch floppy disk drive. It is primarily used within Commodore 64 and 128 hardware emulators to store and execute legacy software, games, and archival applications. As an obsolete binary representation of physical magnetic media, the format is considered inherently safe, posing no modern security risks to contemporary operating systems, hardware, or digital environments.
Validation Code
How to validate .d81 files in Python
Python
def is_d81(file_path: str) -> bool:
"""Check if file is a valid D81 by magic bytes."""
signature = bytes([0xA0, 0x33, 0x44, 0xA0, 0xA0])
with open(file_path, "rb") as f:
return f.read(5) == signatureHow to validate .d81 files in Node.js
Node.js
function isD81(buffer: Buffer): boolean {
const signature = Buffer.from([0xA0, 0x33, 0x44, 0xA0, 0xA0]);
return buffer.subarray(0, 5).equals(signature);
}
Go
func IsD81(data []byte) bool {
signature := []byte{0xA0, 0x33, 0x44, 0xA0, 0xA0}
if len(data) < 5 {
return false
}
return bytes.Equal(data[:5], signature)
}API Endpoint
GET
/api/v1/d81
curl https://filesignature.org/api/v1/d81