Editing IBM System/38 (section)

==Hardware characteristics==
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| image1 = IBM System38 internals (145899278).jpg
| caption1 = Overview of internals
| image2 = S38 III.jpg
| caption2 = Two hard disks
| width2 = 113
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The IBM 5381 System Unit contains processor, main memory, disk storage, a diskette magazine drive, and a system console with keyboard and a display. 5381 was available in Model 100 and Model 200.

The IBM 5382 System Unit is physically identical to 5381, but with more powerful processors, more memory, and more disk storage. 5382 was available in Models 300, 400, 500, 600, and 700.

Users typically interacted with the system through [[IBM 5250]] series terminals. In 1984, IBM added the ability to attach graphics-oriented terminals that previously required a mainframe.<ref>{{cite news
   |newspaper=[[The New York Times]]
   |url=https://www.nytimes.com/1984/06/20/business/changes-at-ibm.html
   |title=Changes at I.B.M. |date=June 20, 1984}}</ref>

===Processing unit===
The system includes a [[central processing unit]] with 512K, 768K, 1024K, 1280K, or 1536K bytes of main storage. The processor is implemented across twenty-nine [[Schottky TTL]] [[Large-scale integration|LSI]] chips mounted on a 10x15" circuit board.<ref name="technical-developments" /> It includes a [[memory management unit]] supporting [[demand paging]], used by the system software to implement a [[single-level store]] architecture.

The System/38 CPU features a [[48-bit computing|48-bit]] address space, which was selected as a compromise between [[64-bit computing|64-bit]] addressing, which certain IBM engineers wanted for the sake of future proofing, and [[32-bit computing|32-bit]] addressing, which other engineers wanted for cost saving purposes.<ref name="inside-as400" />

===System console keyboard/display===
[[File:MNACTEC keyboards (31123489535).jpg|thumb|IBM System/38 console]]
The System/38 [[System console|console]] incorporates a keyboard and a display screen with 16 lines of 64 characters, inconsistent with the locally attached [[IBM 5250|5250]] terminals, which are either 12x40 or 24x80, depending on model. The keyboard is available to the system operator to enter Control Language commands.

===Diskette magazine drive===
The diskette magazine drive is standard on all models.