Talk:Drive letter assignment

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Programs ("tasks")[edit]

Not really competent to comment, but on RSX-11 and VMS we had the extremely clean concept of devices, which could be either physical or logical, and easily controlled through software assignment.

On RSX they had two-letter names with numbers and a colon. I believe on VMS they could be anything.

Hence, if you sent output to TI:, it appeared on your terminal, LP: to the default printer, NL: to the bit bucket, DB2:, whatever disk had that name, TT32:, that particular terminal, etc, etc. Again, on RSX, all activity was controlled by PIP, the Peripheral Interchange Program, so moving files, deleting them, renaming them, printing them, copying them, saving them, was all the same. Programs ("tasks") could do the same. Ortolan88

Other OS?[edit]

What about other OSs that use drive letters? RiscOS? Macs?

Macs, as far as I know, always use the disc's label to refer to it - which has a default like "Macintosh 5020". Remember that until Mac OS X (which is UNIX), there was rarely need to refer to the location of a file in this way, so the verbosity wasn't a problem. RiscOS, on the other hand, I'm not so sure about - Acorns certainly had short disk identifiers of some sort, but I'm not at all sure they weren't numbers rather than letters... - IMSoP 22:40, 12 Feb 2005 (UTC)
RISC OS used numbers and a filing system identifier. For instance, floppy disk drives were controlled by the advanced disc filing system (ADFS) so the first floppy drive was ADFS::0, the second ADFS::1. The root of each FS was $, the directory seperator was . so a typical path was ADFS::0.$.letters.matt (no file extensions). The first IDE drive was ADFS::4, the second ADFS::5 and so on, SCSI drives were SCSI::0 etc. There was also ResourcesFS, from which you could access the files stored in ROM, I can't remember how that was labelled. IIRC there were some pseudo-FSs too. M Blissett 13:11, 14 September 2005 (UTC)Reply[reply]
MacOS (at least prior to X) does have device names. But they are only needed for blood & guts programming. The average user is never confronted with them. —Brian Patrie 13:15, 9 October 2005 (UTC)Reply[reply]


I'd like to know why they chose to assign drive letters the way they did. Why not make the primary partition A, followed by subsequent partitions and then start assigning removeable devices?

Because floppy drives came first and hard drives were invented later. Early PCs had one or two floppy drives so a: and b: were assigned to those. When hard drives came along, the a: and b: assignments couldn't be changed so the hard drives started at c:

After Z:?[edit]

What does Windows call drives beyond Z:? I've wondered about this. Unfortunately, no one yet has provided me with an answer. —Typhlosion 19:14, 12 June 2006 (UTC)Reply[reply]

I always wondered that too, 26 harddrives is the norm in large organisations i would of thought. —allix , 13:07 3 August 2006 (GMT)

Microsoft TechNet says 'You can create more than 26 volumes with Windows, but you cannot assign more than 26 drive letters for accessing these volumes. ... Volumes created after the 26th drive letter has been used must be accessed using volume mount points'. Like to add this to the article? PeterGrecian 12:48, 27 November 2006 (UTC)Reply[reply]
I've added it now. PeterGrecian 18:31, 1 December 2006 (UTC)Reply[reply]
After Z:? Maybe numbers? I don't know (If you ask why number, it's just I got it somewhere in a wacky error message {saying that "8:" isn't valid}). AppleMacReporter 01:49, 19 January 2007 (UTC)Reply[reply]
There are tons of servers at our organisation too, but I use a Windows app to map the network drives only when I need them. Works for me. [1] —Preceding unsigned comment added by (talk) 16:41, 28 February 2008 (UTC)Reply[reply]

You can't make more drives than Z:. I've always wondered why MS-DOS doesn't allow drives like AA:, AB: etc. Like the article mentions, you can use volume mount points, which can achieve access to further volumes, but not with drive letters. Most frustrating… — OwenBlacker (Talk) 15:44, 14 June 2008 (UTC)Reply[reply]

Back around the MS-DOS 3 days, the underlying code of one version of DOS supported 32 drives, and I remember one columnist to a computer magazine reporting that he was actually using at least 31, with the last five drive "letters" being "[:", "\:", "]:", "^:", and "_:" (these being the characters which immediately follow "Z" in ASCII). This loophole was apparently quickly eliminated in subsequent DOS versions... AnonMoos (talk) 13:08, 24 September 2008 (UTC)Reply[reply]

Recognized → recognised[edit]

I note an edit today changing recognized to recognised in this article. Basically, you should have left this spelling in place. See [Manual of Style, on style disputes]: is inappropriate for a Wikipedia editor to change from one style to another unless there is some substantial reason for the change. For example, with respect to British spelling as opposed to American spelling, it would only be acceptable to change from American spelling to British spelling if the article concerned a British topic. Revert warring over optional styles is unacceptable; if the article uses colour rather than color, it would be wrong to switch simply to change styles, although editors should ensure that articles are internally consistent. If in doubt, defer to the style used by the first major contributor.

Not a big deal, but the goals are internal consistency, and following the style of the original contributor. Not to mention that CP/CMS, CP/M, and Microsoft products all have US origins. I have not reverted the spelling, but future edits should seek consistency here. Trevor Hanson 19:12, 22 November 2006 (UTC)Reply[reply]


user:Mecu reverted an edit by, identifying it as vandalism. This is the text that was restored:

(Win98 update really likes to put any CD-ROM drive as D:\ even putting it above a Primary Partition IDE device)

It was removed with the edit comment "removed a casual comment".

I think this was a legitimate edit, definitely not vandalism. You might disagree with the change, but I think you should assume good faith. The text in question is non-encyclopaedic and unsourced. When I saw the change I thought "yeah, that probably doesn't belong here." Trevor Hanson 03:57, 24 April 2007 (UTC)Reply[reply]

I saw it as well, and also thought it wasn't real vandalism (but understood Mecu's motivations). I have vague memories of my D: being remapped back in the days I used Win98, so it appears to be have been legitimately informative. OTOH, it may be an urban myth, so I have tagged it with {{cn}}. John Vandenberg 04:28, 24 April 2007 (UTC)Reply[reply]


Some of this is written in such a way that when I read it, it sounds as though it is from one specific person's point of view and is based on their personal experiences. The article should be reviewed so that it is more neutral.--Wraithdart 16:06, 13 June 2007 (UTC)Reply[reply]

It's possible that you are referring to the material which I added about the role of CP/CMS in the history of drive letter assignments. Last November, when working on CP/CMS, History of CP/CMS, IBM CP-40, IBM M44/44X, and related material, I came across the drive letter assignment article, which stated that drive letter assignment "might have originated in the CP/M operating system". It of course made sense that MS/DOS and Windows drive letter assignment would have come from CP/M; but I had just been reading sources that talked about Gary Kildall's experience with CP/CMS, and its role as an inspiration for CP/M. I added what seemed to be the appropriate historical detail.
The relevant citations are in the various CP/CMS articles. I will try to find some specific ones to mention here, but I don't think there's any real question about the chain of design influences that passed from CP/CMS to CP/M to MS/DOS. (As far as the technical details are concerned, e.g. 'drive type' in CP/CMS, that is amply documented in the relevant articles.)
If I've missed the point here, please let me know what material you feel lacks neutrality, or any claims made that you think are in doubt. Trevor Hanson 17:08, 13 June 2007 (UTC)Reply[reply]

Playstation & Xbox[edit]

I am not sure where the playstation(2?) could be seen to use drive letters. For homebrew, mc0:, mc1: pfs: are used. [and others usb: net: .... pfs: = harddisk--, another also exists for harddisk / is the actual harddisk and this is the mount. --but I don't have my console in front of me.] In official Sony applications/games memory cards are just "Memory Card 1" or "2" [ or similar if i guessed wrong. -- I don't know what they call the hdd]. In Linux on the Playstation 2 [Sony's or I imagine any other.] the operation is the same as any normal linux. Maybe in the actual software development environment, they might be 'A' or 'B'? I have never seen that though. If I get the time, I will review who added it, and if it was more descriptive initially.

No arguments with Xbox, however it may be necessary to specify the first xbox since I doubt the 360 uses them in any way. the first xbox was very similar to a standard/traditional pc, stripped down a bit. All of the xbox's drive letters were/are hardcoded into the bios. The official ones are c-Base user interface application. and xboxlive, d-DVDrom, e-gamesaves, downloaded content, stored music, x-y-z were all cache. off the top of my head I think that c was 128mb?, and xyz each 768? and e-4 or 5 gb. the sizes and geometry were also hardcoded in the bios. to add additional drive letters required a custom bios and larger harddisk, and would usually [always?] be f&g. the utilized space on any xbox hdd was ~8gb, not used/free, but assigned. some xboxes had 8gb hdds and some 10gb. the models with a 10gb unit did not take advantage of it, and it would be possible to map it using a custom bios. [where custom equals third party/ homebrew].

sorry for the longwinded and strange comment, i seem to have wandered from my own point [ not that i knew what it was].

---PidGin128 from 13:04, 15 October 2007 (UTC)Reply[reply]

It may also be worth noting the abstraction of drive letters themselves. since the electronics don't care what we name things. this is especially true for the older/classic computers where you might really just be enabling a port for read or write access, and.... don't really know what I am talking about here...
for a[non older/classic machines] example, a machine dual booting linux and windows. drive d: may be /dev/sdb1. the filesystem could be fat32, and neither would have issues accessing the same files.
again apologies for this patchwork sentence structure. very early. and i think i am thinking about hardware level address lines too much to be looking at a driveletter assignment article, which i suspect i was talking about above. ---PidGin128 from 13:14, 15 October 2007 (UTC)Reply[reply]

Amiga section[edit]

IMHO, this section is off-topic; I think this article should concentrate on CP/M/DOS/Windows-style single-letter drive identifiers, otherwise it becomes a general discussion of OS device/volume naming schemes, and that is a different article altogether. Letdorf (talk) 12:35, 23 March 2008 (UTC).Reply[reply]

Inheriting A: and B:[edit]

With the death of the floppy, what will take its place for A: and B: assignments? Jigen III (talk) 14:59, 14 August 2010 (UTC)Reply[reply]

As far as I know nothing is automatically assigned to these letters, at least in Windows versions up to 7. However they can be assigned manually to any drive. When I needed to assign a persistent letter to my external hard drive I made it A: just because it always bothered me that those two went unused (and it's my main drive for storing files, so it makes sense to me for it to come first). Also I know enough people who still think of 'A: drive' as synonymous with 'floppy disk' that it's fun to tell people I have 160GB of music on the A: drive and see the look on their faces. (talk) 16:55, 10 March 2014 (UTC)Reply[reply]
On this Win 7 box (and probably many others) there is a multi-gigabyte NTFS disk living happily on the "B" slot. This is a minor issue, as in developing a batch script to scan existing HDDs for folders, the documented default HDD drive set is still {C,D,E,F,G).--Lmstearn (talk) 02:52, 21 November 2014 (UTC)Reply[reply]

Request for Comments: c: link prefix for Wikimedia Commons[edit]

There is a cross-wiki discussion in progress as to whether c: should be enabled globally as an interwiki prefix for links to the Wikimedia Commons. If the proposal gains consensus this will require the deletion or renaming of several pages on the English WIkipedia whose titles begin with "C:", including one or more redirects to this page. Please take a moment to participate in the discussion.
There is also a related discussion on the English Wikipedia at Wikipedia:Redirects for discussion/Log/2014 February 16#C:ATT to which you are invited to contribute.
Thank you. Thryduulf (talk) 15:28, 1 March 2014 (UTC)Reply[reply]

New Windows behavior?[edit]

Didn't Windows Vista (or 7) introduce a different behavior, where the boot partition (the one with the WINDOWS folder) is always assigned the letter C, even if it is not the first primary partition? Or was that in some pre-release version and dropped later? --Xerces8 (talk) 19:17, 22 June 2014 (UTC)Reply[reply]

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