Editing IBM System/3 (section)

===Direct access storage===
{{See also|IBM 5444}}
For mass storage, the System/3 used the [[IBM 5444]] single-platter [[hard disk|disk]],<ref>[http://ed-thelen.org/comp-hist/IBM-ProdAnn/syst3.pdf System/3], IBM engineering announcement</ref> roughly the size of a large pizza; initially each platter held 2.5 MB of data. Standard configuration for storage was one or two fixed disks, each in a separate pull-out drawer, which typically held the operating system and user-developed programs. Additionally, each fixed disc could have a removable cartridge disk attached; these typically contained the data-files associated with various applications, for example Payroll, and users frequently had a number of them. Thus the low-end systems could support a maximum of 10 MB of online storage (two fixed, two removable), although in practice this was very expensive and not common.

The System/3 was also available with the IBM 5445 disk drive (20mb) and later the model 15 allowed "winchester" style 3340 drives. On the smaller models, while you could attach 5445 drives, you had to keep the 5444 for the operating system and other programming libraries, however that limitation was changed with software called elimn8 which allowed 5445 drives to totally replace the 5444's. Other companies such as Memorex manufactured compatible 5445 drives for the System/3.