IBM System/370 Model 155: Difference between revisions

Revision as of 08:14, 12 May 2024

Revision as of 08:18, 12 May 2024

Line 66:

In 1972 an upgrade option was announced "to provide the hardware necessary to operate in a virtual memory mode."<ref>{{cite news|newspaper=Computerworld|date=August 15, 1973|page=17|title=First IBM DAT Box Installed|url=https://books.google.com/books?id=T3qky0Z-gc0C&pg=PA17}}</ref>

In 1972 an upgrade option was announced "to provide the hardware necessary to operate in a virtual memory mode."<ref>{{cite news|newspaper=Computerworld|date=August 15, 1973|page=17|title=First IBM DAT Box Installed|url=https://books.google.com/books?id=T3qky0Z-gc0C&pg=PA17}}</ref> Unlike the [[IBM System/370 Model 145]], which as early as June 1971 couldincluded havethe virtualhardware memorynecessary capabilityto addedsupport tovirtual itmemory, withand afor simplewhich a [[microcode]] update from a floppy disk, adding support for virtual memory, was announced in 1972, the Model 155 and Model 165 needed expensive hardware additions—additions - $200,000 for the 155 and $400,000 for the 165—to165 - to add virtual memory capability, and even this had to wait until 1972, at which time. theirAn upgraded 155 was known as an IBM System/370 Model 155-II.<ref>{{cite journal | author = A. Padegs | title = System/360 and Beyond | journal = IBM Journal of Research & Development | volume = 25 | issue = 5 | pages = 377–390 |date=September 1981 | publisher = IBM | doi = 10.1147/rd.255.0377}} &ndash; tables include model characteristics (Table 1) and announcement/shipment dates (Table 2). The S/370-155-II and -165-II are listed under the former but not the latter, because the upgraded systems were not formally announced as separate models. The "System/370 Advanced Function" announcement, including the -158 and -168, was the main public event.</ref>

==Physical memory==