{{more footnotes needed|date=March 2025}} The IBM '''Virtual Machine Communication Facility''' (VMCF) is a feature of the VM/370 operating system introduced in Release 3 in 1976. It "provides a method of communication and data transfer between virtual machines operating under the same VM/370 system."<ref name="Intro">{{cite book |last1=IBM Corporation |title=IBM Virtual Machine Facility/370: Introduction, Release 3 PLC 8 |date=October 1976 |page=nn |url=http://bitsavers.org/pdf/ibm/370/VM_370/Release_3/GC20-1800-6_VM370_Introduction_Rel_3_Oct76.pdf |accessdate=Aug 17, 2019}}</ref>
VMCF uses paravirtualization through the ''diagnose'' instruction VMCF <code>SEND</code> function to send data, in blocks of up to 2048 bytes, from one virtual machine to another. The receiving virtual machine accesses the data thru the diagnose <code>RECEIVE</code> function. It provides a simpler interface and greater performance than the prior use of virtual channel-to-channel adapters for the same purpose.<ref>{{cite journal |last1=Jensen |first1=R.M. |title=A formal approach for communication between logically isolated virtual machines |journal=IBM Systems Journal |date=1979 |volume=18 |issue=1 |pages=71–92 |citeseerx=10.1.1.91.1907 |doi=10.1147/sj.181.0071 }}</ref>
VMCF was superseded by the Inter User Communication Vehicle (IUCV), introduced in 1980 with VM/SP.
==References== {{Reflist}} {{refbegin}} :*{{cite journal |last1=Jensen |first1=R. M. |title=A formal approach for communication between logically isolated virtual machines |journal=IBM Systems Journal |date=1979 |volume=18 |issue=1 |pages=71–92 |doi=10.1147/sj.181.0071 |url=https://ieeexplore.ieee.org/document/5387987 |access-date=29 March 2025 |issn=0018-8670|publisher=Institute of Electrical and Electronics Engineers|url-access=subscription }}
:*{{cite journal |title=Proceedings |journal=The Second International Conference on Computers and Applications, Beijing (Peking), People's Republic of China, June 23–27, 1987 |date=June 1987 |page=360 |url=https://books.google.com/books?id=_r0sAQAAIAAJ&q=%22Virtual%20Machine%20Communication%20Facility%22%20-wikipedia |access-date=29 March 2025 |publisher=Institute of Electrical and Electronics Engineers |isbn=978-0-8186-8780-8 |language=en}}
{{refend}}
==External links== * {{cite journal |last1=Date |first1=Shashank Prabhakar |title=A multi-tasking hierarchical file system for VM/CMS using virtual machine communication |url=https://uh-ir.tdl.org/items/4987f38b-f495-42e6-abc5-0ad031839a0d |website=University of Houston |date=1986 |access-date=March 30, 2025}} * {{cite web |last1=Faconti |first1=G |last2=Santoro |first2=N |title=APL106 VSAPL Virtual Machine Communication Facility Auxiliary Processor |url=https://iris.cnr.it/retrieve/1c6e93de-c692-4af5-84dd-af2fb2a34b50/prod_421826-doc_149866.pdf |website=Consiglio Nazionale della Ricerche |access-date=Mar 30, 2025}} * {{cite journal |last1=Jensen |first1=R.M. |title=A formal approach for communication between logically isolated virtual machines |journal=IBM Systems Journal |date=March 1979 |volume=18 |issue=1 |pages=71–92 |url=https://dl.acm.org/doi/10.1147/sj.181.0071 |doi=10.1147/sj.181.0071 |access-date=March 30, 2025|url-access=subscription }}
{{DEFAULTSORT:Virtual Machine Communication Facility}} Category:IBM mainframe operating systems Category:VM (operating system) Category:Virtualization
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