A post from 2008--Where does [name your favorite computer-related advance] go?--summarized numerous changes in 004–006 Computer science; computer programming, programs, data; special computer methods as announced in the November 2008 New and Changed Entries (in Word and PDF formats). Additional changes in 004–006 have been made since then. This is the first of several posts that will delve into both sets of changes, all of which are now available in DDC 23. This post focuses on changes pertaining to hardware and storage in 004 Computer science; subsequent posts will address changes pertaining to networking and communications in 004, as well as changes in 005 Computer programming, programs, data and 006 Special computer methods.
Two general trends pertaining to the functionality and size of computing devices have been addressed. The first trend is the proliferation of smaller computing devices, which has motivated an expansion for handheld computing devices at 004.167 (as well as expansions at 004.1675 Specific handheld computing devices and 005.25 Programming for handheld computing devices). An example of a book that should be classed at 004.167 is The 2007-2012 world outlook for portable handheld computers, while BlackBerry Storm for dummies should be classed at 004.1675. Related numbers in 005 do not distinguish between handheld computing devices in general and specific handheld computing devices. Thus we class The Android developer's cookbook: building applications with the Android SDK 005.25 Programming for handheld computing devices. (Note that there is not as yet a separate number for programs for handheld computing devices; thus Brilliant Blackberry apps for dummies belongs in 005.36 Programs for personal computers, which contains the note “Including programs for handheld computing devices.”)
The second trend is that many computing devices are multifunctional. For example, in addition to running application software, many handheld computing devices can also serve as cameras, phones, and/or portable media playes. A note at 004.11–004.16 Digital computers instructs that multifunctional devices should be classed with their predominant function. Thus works on smartphones, for instance, will generally be classed with handheld computing devices rather than with mobile phones, cameras, or portable media players, as already seen in the examples above.
It is instructive to note that the class-here note at 004.16 Personal computers, which in DDC 22 enumerated specific types of microcomputers has been replaced by a more generic note (“Class here specific types of personal computers”). This means that all specific types of personal computers now approximate the whole of 004.16, not just those named in the note.
Under 004.56 External storage (Auxiliary storage), three kinds of changes have been made. First, provision has been made for a new class of storage at 004.568 Semiconductor storage. The class-here note at that number mentions solid-state storage, flash drives, and memory cards. Second, the coordinate classes have been given new captions (“Magnetic storage” and “Optical storage”) in parallel with the caption at 004.568. Third, the including and class-here notes at 004.56 and its subordinate classes have been updated.
Examples of recent works that should be classed in the three classes under 004.56 include the following: IBM TotalStorage 3494 tape library: a practical guide to tape drives and tape automation at 004.563 Magnetic storage (where both magnetic tapes and tape drives are mentioned in the including note); Holographic data storage: from theory to practical systems at 004.565 Optical storage; and The 2007-2012 world outlook for NAND flash memory cards at 004.568 Semiconductor storage.
Parallel modifications to the changes discussed above have been made in Engineering, at 621.39167 Handheld computing devices and 621.3976 External storage (Auxiliary storage).