ATR File Format Description

## Programs

Used widely by emulators, SIO2PC & APE peripheal emulators.

## Conventions

DWORD - 32bit unsigned long (little endian)
WORD - 16bit unsigned short (little endian)
BYTE - 8bit unsigned char

## Header

16 bytes long.

Type | Name | Description
--- | --- | ---
WORD | wMagic | $0296 (sum of 'NICKATARI')
WORD | wPars | size of this disk image, in paragraphs (size/$10)
WORD | wSecSize | sector size. ($80 or $100) bytes/sector
BYTE | btParsHigh | high part of size, in paragraphs (added by REV 3.00)
DWORD | dwCRC | 32bit CRC of file (added by APE?)
DWORD | dwUnused | unused
BYTE | btFlags | bit 0 (ReadOnly) (added by APE?)

## Body

Then there are continuous sectors. Some ATR files are incorrect - if sector size is > $80 first three sectors should be $80 long. But, few files have these sectors $100 long.

Format was created by Nick Kennedy. Back (c) 1998-2004 Jindroush Last modified: Sun Dec 5 19:32:02 1999