IBM System/360 Model 30: Difference between revisions

Revision as of 16:15, 27 June 2019

Revision as of 03:46, 22 July 2019

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The microcode was stored in [[CCROS]] (Card Capacitor Read-Only Storage) developed in Endicott. The Model 30 and Model 40 were originally supposed to share the [[transformer read-only storage]] (TROS) being developed at [[IBM Hursley]], but CCROS was cheaper to manufacture.<ref name= ibmbook/> This system used [[Mylar]] cards the size and shape of a standard IBM [[punched-card]], so the microcode could be changed using a [[keypunch]]. Each card held 720 bits, and the total microcode consisted of 4032 60-bit words. The Mylar "encased copper tabs and access lines."<ref name="encyc">{{cite book |last1=Kent (ed.) |first1=Allen |title=Encyclopedia of Library and Information Science: Volume 69 - Supplement 32 |date=2000 |publisher=CRC Press |isbn=0-8247-2069-5 |page=267 |url=https://books.google.com/books?id=1U_gOuKGFYYC&pg=PA267 |accessdate=Dec 3, 2018}}</ref> A hole punched at a specific ___location removed the copper tab and encoded a zero, unpunched locations were read as ones.<ref name="encyc"/>

[[File:Ibm 360-30.jpg|thumb|IBM 360 model 30 front panel and internal components]]

==System configuration==

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|Tape storage || two [[IBM 2415]] Magnetic Tape Units (180 & 181)

|}

[[File:IBM 360-30.jpg|thumb|210x210px|IBM 360 model 30 front panel closeup]]

==System software==