Macintosh File System

Short description: Disk file system by Apple Computer

MFSDeveloper(s)| Apple Computer, Inc.

|

Full name| Macintosh File System
Introduced| January 24, 1984; 42 years ago (1984-01-24) with System 1
Partition identifier| `Apple_MFS` (Apple Partition Map)
Structures
Directory contents| Table
File allocation| Linked list
Bad blocks| No
Limits
Max. volume size| 20 MiB
Max. file size| 20 MiB
Max. number of files| 4094
Max. filename length| 255 characters
Allowed characters in filenames| Any printable character except “:”
Features
Dates recorded| Creation, modification
Date range| January 1, 1904 – February 6, 2040
Date resolution| 1s
Forks| Only 2 (data and resource)
Attributes| version, locked, type, creator, Finder window, location in Finder window, Finder flags
File system permissions| No
Transparent compression| No
Transparent encryption| No
Other
Supported operating systems| System 1 — Mac OS 7.6,
Mac OS 7.6.1 (read-only)

Macintosh File System (MFS) is a volume format (or disk file system) created by Apple Computer for storing files on 400K floppy disks. MFS was introduced with the original Apple Macintosh computer in January 1984.

MFS is notable both for introducing resource forks to allow storage of structured data, and for storing metadata needed to support the graphical user interface of the classic Mac OS. MFS allows file names to be up to 255 characters in length,[1] although Finder does not allow users to create names longer than 63 characters (31 characters in later versions). MFS is called a flat file system because it does not support a hierarchy of directories.

Folders exist as a concept on the original MFS-based Macintosh, but work completely differently from the way they do on modern systems. They are visible in Finder windows, but not in the open and save dialog boxes.[2] There is always one empty folder on the volume, and if it is altered in any way (such as by adding or renaming files), a new Empty Folder appears, thus providing a way to create new folders. MFS stores all of the file and directory listing information in a single file. The Finder creates the illusion of folders, by storing all files as pairs of directory handles and file handles. To display the contents of a particular folder, MFS scans the directory for all files in that handle. There is no need to find a separate file containing the directory listing.

The Macintosh File System does not support volumes over 20 MB in size, or about 1,400 files.[citation needed] While this is small by today's standards, at the time it seemed very expansive when compared to the Macintosh's 400 KB floppy drive.

Apple introduced Hierarchical File System as a replacement for MFS in September 1985. In Mac OS 7.6.1, Apple removed support for writing to MFS volumes “as such writes often resulted in errors or system hangs”,[3] and in Mac OS 8.0 support for MFS volumes was removed altogether. Although macOS has no built-in support for MFS, an example VFS plug-in from Apple called MFSLives provides read-only access to MFS volumes.[4]

## Contents

* 1 See also
* 2 Citations
* 3 General and cited references
* 4 External links

## See also

* Comparison of file systems

## Citations

1. ↑ Langowski, Jörg (April 1985). "Disks". MacTech 1 (5). http://mactech.com/articles/mactech/Vol.01/01.05/Disks/. Retrieved 2023-03-23.
2. ↑ Brecher, Steve. "HFS File Structure Explained". MacTech 1 (12). http://www.mactech.com/articles/mactech/Vol.01/01.12/HFSFileStructure/index.html. Retrieved 2023-03-23.
3. ↑ "Technote 1096: Mac OS 7.6.1". Apple Inc.. https://developer.apple.com/technotes/tn/tn1096.html.
4. ↑ "MFSLives". 2006-11-09. https://developer.apple.com/library/archive/samplecode/MFSLives/Introduction/Intro.html.

## General and cited references

* Apple Computer, Inc. (1985). Inside Macintosh Volume II. New York: Addison-Wesley. ISBN 0-201-17732-3.

## External links

* Apple Tech Article 9502—MFS volume support in Mac OS 7.x
* Resurrecting MFS Macintosh Floppies
* Fred's Follies—HFS used in Macs with 128K ROMs different from MFS used in Macs with 64K ROMs
* Q&A: Mac Plus —limitation due to MFS on an external 400K floppy drive disk

* v
* t
* e

Classic Mac OS

Versions|

* System 1
* System 2, 3, and 4
* System 5
* System 6
* System 7
* Mac OS 7
* Mac OS 8
* Mac OS 9

Applications|

* Calculator
* Chooser
* Drive Setup
* DVD Player
* Finder
* Graphing Calculator
* Keychain Access
* PictureViewer
* PowerTalk
* QuickTime Player
* Network Browser
* Scrapbook
* Sherlock
* Software Update
* Stickies
* System Information
* SimpleText

Developer|

* HyperCard
* MacsBug
* Macintosh Programmer's Workshop
* ResEdit

Technology|

* Alias
* Appearance Manager
* Apple menu
* At Ease
* Balloon help
* Bomb error
* Command key (⌘)
* Control Panel
* Control Strip
* Creator code
* Dogcow
* Extensions
* Hierarchical File System
* HFS Plus
* Keychain
* Labels
* Macintosh File System
* Macintosh Toolbox
* Managers
* Menu blinking
* MultiFinder
* Option key (⌥)
* OSType
* PICT
* QuickDraw
* QuickTime
* Resource fork
* Sosumi sound
* Startup sequence
* System folder
* System suitcase
* Type code
* WorldScript

Related articles|

* Memory management
* Old World ROM
* New World ROM
* Software

* v
* t
* e

File systems

* Comparison of file systems
* distributed
* Unix filesystem

Disk|

* ADFS
* AdvFS
* Amiga FFS
* Amiga OFS
* APFS
* AthFS
* bcachefs
* BFS
* Be File System
* Boot File System
* Btrfs
* CVFS
* CXFS
* DFS
* EFS
* Encrypting File System
* Extent File System
* Episode
* ext
* ext2
* ext3
* ext3cow
* ext4
* FFS/FFS2
* FAT
* exFAT
* Files-11
* Fossil
* HAMMER
* HAMMER2
* HFS
* HFS+
* HPFS
* HTFS
* IBM Spectrum Scale
* JFS
* LFS
* MFS
* Macintosh File System
* TiVo Media File System
* MINIX
* NetWare File System
* Next3
* NILFS
* NILFS2
* NSS
* NTFS
* OneFS
* PFS
* QFS
* QNX4FS
* ReFS
* ReiserFS
* Reiser4
* Reliance
* Reliance Nitro
* RFS
* SFS
* SNFS
* Soup (Apple)
* Tux3
* UBIFS
* UFS
* soft updates
* WAPBL
* VxFS
* WAFL
* Xiafs
* XFS
* Xsan
* zFS
* ZFS

Optical disc|

* HSF
* ISO 9660
* ISO 13490
* UDF

Flash memory and SSD|

* APFS
* FAT
* exFAT
* CHFS
* TFAT
* EROFS
* FFS2
* F2FS
* HPFS
* JFFS
* JFFS2
* JFS
* LogFS
* NILFS
* NILFS2
* NVFS
* YAFFS
* UBIFS

Distributed|

* CXFS
* GFS2
* Google File System
* OCFS2
* OrangeFS
* PVFS
* QFS
* Xsan
* more...

NAS|

* AFS (OpenAFS)
* AFP
* Coda
* DFS
* Google File System
* IBM Spectrum Scale
* Lustre
* NCP
* NFS
* POHMELFS
* Hadoop
* SMB (CIFS)
* SSHFS
* more...

Specialized|

* Aufs
* AXFS
* Boot File System
* CDfs
* Compact Disc File System
* cramfs
* Davfs2
* EROFS
* FTPFS
* FUSE
* Lnfs
* LTFS
* NOVA
* MVFS
* SquashFS
* UMSDOS
* OverlayFS
* UnionFS
* WBFS

Pseudo and virtual|

* configfs
* devfs
* debugfs
* kernfs
* procfs
* specfs
* sysfs
* tmpfs
* WinFS

Encrypted|

* eCryptfs
* EncFS
* EFS
* Rubberhose
* SSHFS
* ZFS

Types|

* Clustered
* Global
* Grid
* Self-certifying
* Flash
* Journaling
* Log-structured
* Object
* Record-oriented
* Semantic
* Steganographic
* Synthetic
* Versioning

Features|

* Case preservation
* Copy-on-write
* Data deduplication
* Data scrubbing
* Execute in place
* Extent
* File attribute
* Extended file attributes
* File change log
* Fork
* Links
* Hard
* Symbolic

Access control|

* Access control list
* Filesystem-level encryption
* Permissions
* Modes
* Sticky bit

Interfaces|

* File manager
* File system API
* Installable File System
* Virtual file system

Lists|

* Cryptographic
* Default
* Log-structured

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Macintosh File System. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Macintosh_File_System&oldid=261273"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template