{{redir|DOS/NT|the similarly named DOS emulator in Windows NT|NTDOS}} {{short description|Italian-American programmer and original developer of the FreeDOS kernel}} {{Use dmy dates|date=April 2019|cs1-dates=y}} {{Use list-defined references|date=December 2021}} {{Infobox person |name = Pat Villani |image = |birth_name = Pasquale J. Villani |birth_date = {{Birth date|1954|04|18|df=yes}} |birth_place = Nocera Inferiore, Italy |death_date = {{Death date and age|2011|08|27|1954|04|18|df=yes}} |death_place = Freehold Township, New Jersey, USA |death_cause = |resting_place = <!-- Freehold Township, New Jersey, USA --> |nationality = |other_names = |siglum = patv |known_for = author of DOS-C, the FreeDOS kernel |education = Master's in Electrical Engineering from Polytechnic Institute of New York; Master's in Project Management from George Washington University |alma_mater = |employer = |occupation = |spouse = <!-- Donna Elsworth Villani --> |children = <!-- Erika Villani --> |parents = |callsign = WB2GBF <!-- amateur radio call sign --> }} '''Pasquale "Pat" J. Villani'''<ref name="Villani_2009_Name"/> (18 April 1954 – 27 August 2011) was an American computer programmer, author, and advocate of free software, best known for his creation of DOS-C, a DOS emulator written in the C language and subsequently adapted as the kernel of the FreeDOS operating system and a number of other projects including DOSEMU for Linux. He used to sign his edits with siglum "patv".
== FreeDOS involvement == Villani had already been working on a DOS-like operating system for use in embedded systems for some while before the advent of FreeDOS.<ref name="FLOSS"/>
His efforts started when he developed an MS-DOS 3.1-compatible interface emulator to write device drivers in the C high-level language instead of in assembly language,<ref name="Villani_1996_Kernel"/> as was the usual approach at that time. This interface emulator grew into a minimal operating system named '''XDOS''' around 1988.<ref name="Villani_1996_Kernel"/>
He added an IPL to set up a boot environment before loading the actual operating system and developed an MS-DOS-compatible frontend API to applications.<ref name="Villani_1996_Kernel"/> In contrast to MS-DOS, which is not designed to be reentrant, the system calls of his operating system were,<ref name="Villani_1996_Kernel"/> which is often a requirement for multitasking and real-time applications in embedded systems. This system was named '''NSS-DOS''' and also offered commercially.<ref name="Villani_1996_Kernel"/>
When one potential contractor sought to use the OS in a system equipped with Motorola 680x0 processors instead of Intel x86 processors, for which the system was designed originally and which utilize different instruction sets and memory models, Villani was able to redesign his system to become portable across a range of different compilers and target environments.<ref name="Villani_1996_Kernel"/> This move to a completely different target platform, while losing binary compatibility with existing applications, would have required a complete rewrite from scratch had his system not been written in a high-level language such as C, which allowed him to reuse large parts. His new '''DOS/NT''' used a microkernel architecture with logical separation of file system, memory and task manager.<ref name="Villani_1996_Kernel"/>
250px|right Villani joined the FreeDOS project in 1994 after reading Jim Hall's announcement of a "PD-DOS" on [news:comp.os.msdos.apps comp.os.msdos.misc.apps].<ref name="Hall_1994_Announcement"/> In response to Hall's announcement, Villani devised a derivative of DOS/NT named '''DOS-C''' with a monolithic kernel and an architecture more similar to the non-multitasking MS-DOS,<ref name="Villani_1996_Kernel"/> and in 1995 he made it available for dual-use under a GPL<ref name="Villani_2009_Name"/> open-source license to become the kernel component of the new "Free-DOS" operating system, as "PD-DOS" was called at this time.<ref name="Hall_History"/><ref name="Hall_2002_History"/>
In 1996, Villani wrote the book ''FreeDOS Kernel'',<ref name="Villani_1996_Kernel"/> which describes the design of the DOS-C / FreeDOS kernel and the original FreeDOS COMMAND.COM command line interpreter. The name of the operating system was subsequently officially changed to FreeDOS to reflect the spelling used in the book.<ref name="Hall_2002_History"/>
Internally, the FreeDOS kernel was still significantly different from MS-DOS, which, while no problem for embedded applications specifically written for FreeDOS, caused various compatibility issues in conjunction with misbehaving DOS applications. Villani and other contributors analyzed and addressed many of these issues over the years for FreeDOS to become much more MS-DOS compatible.
With some breaks Villani remained active with the FreeDOS project, including preparations for the release of FreeDOS 1.1. Since 2009<ref name="Hall_History"/> he had also held the role of the project coordinator, but he had to step down in April 2011 for health reasons.<ref name="Villani_2011_Stepdown"/> The FreeDOS 1.1 release, published on 2 January 2012, is dedicated to him.
== Biography == Villani was born in Nocera Inferiore<ref name="Villani_2011_Obit1"/> near Naples, Italy,<ref name="Villani_2009_Name"/> grew up in Brooklyn,<ref name="Pat_Villani_Homepage_Bio"/> New York, USA, and moved to Freehold Township,<ref name="Villani_2011_Obit1"/> New Jersey in 1990.
In 1976, he received his BSEE degree from Polytechnic Institute of Brooklyn<ref name="Unigroup_2000_News"/> and in 1981 an MSEE degree in electrical engineering from Polytechnic Institute of New York.<ref name="Unigroup_2000_News"/> In 2008, he also received a master's certificate in Project Management from George Washington University and he was an adjunct professor at Brookdale Community College beginning in 2010.
He previously worked for Stratus Computers, Inc.<ref name="Unigroup_2000_News"/> on their Continuum fault-tolerant product line and also as a consultant for AT&T Bell Laboratories. At Digital Equipment Corporation<ref name="Villani_2011_DEC"/> / Compaq<ref name="Unigroup_2000_News"/> he worked as a principal software engineer on the OSF/1 / Digital UNIX / Tru64 UNIX operating system<ref name="Unigroup_2000_News"/><ref name="Villani_2011_DEC"/> beginning in 1995, and since 2006 had been Acting Director of Communications Infrastructure and Software Architect for Vonage.
He was a member of MARS, ARRL, and IEEE.<ref name="Villani_2011_Obit1"/><ref name="Villani_2011_Obit2"/>
== Bibliography == * {{cite book |author-first=Pat |author-last=Villani |author-link=Pat Villani |date=1996 |title=FreeDOS Kernel - An MS-DOS Emulator for Platform Independence & Embedded System Development - Master OS Development |publisher=R&D Books |location=Lawrence, USA |isbn=978-0-87930-436-2 |id={{ISBN|0-87930-436-7}}}} * {{cite book |author-first=Pat |author-last=Villani |author-link=Pat Villani |date=2001 |title=Programming Win32 Under The API |publisher=Taylor & Francis |isbn=978-1-57820-067-2}} * US patent application number: 12/779,489, publication number: US 2010/0290455 A1, filing date: 2010-05-13, ''Method and apparatus for communication termination routing'', ([https://www.google.com/patents?id=SP3bAAAAEBAJ]{{dead link|date=January 2025|bot=medic}}{{cbignore|bot=medic}}). * US patent application number: 12/897,405, publication number: US 2011/0081009 A1, filing date: 2010-10-04, ''Method and apparatus for providing an identifier for a Caller ID function in a telecommunication system'', ([https://www.google.com/patents?id=TflpAQAAEBAJ]{{dead link|date=January 2025|bot=medic}}{{cbignore|bot=medic}}).
== References == {{Reflist|refs= <ref name="FLOSS">{{FLOSSweekly|416|Hall, Jim}}</ref> <ref name="Villani_2009_Name">{{cite web |author-first=Pat |author-last=Villani |author-link=Pat Villani |date=2009-07-28 |title=On the GPL for FreeDOS and Pat Villani's name |work=freedos-kernel@lists.sourceforge.net |url=http://comments.gmane.org/gmane.comp.emulators.freedos.kernel/1673 |access-date=2011-11-26 |url-status=live |archive-url=https://archive.today/20130414220925/http://comments.gmane.org/gmane.comp.emulators.freedos.kernel/1673 |archive-date=2013-04-14 |quote=I am of Italian origin and my first name is Pasquale, not Patrick. I use Pat as a nickname.}}</ref> <ref name="Villani_1996_Kernel">{{cite book |author-first=Pat |author-last=Villani |author-link=Pat Villani |date=1996 |title=FreeDOS Kernel - An MS-DOS Emulator for Platform Independence & Embedded System Development - Master OS Development |publisher=R&D Books |location=Lawrence, USA |isbn=978-0-87930-436-2 |id={{ISBN|0-87930-436-7}}}}</ref> <ref name="Hall_1994_Announcement">{{cite newsgroup |author-first=James F. |author-last=Hall |author-link=Jim Hall (computer programmer) |date=1994-06-29 |url=http://groups.google.com/group/comp.os.msdos.apps/browse_thread/thread/a10993e044dc4b35/e1bb36f1f0d1513b?lnk=st&q=&rnum=26#e1bb36f1f0d1513b |title=PD-DOS project announcement |newsgroup=comp.os.msdos.apps |access-date=2008-06-14 |url-status=live |archive-url=https://archive.today/20171118005754/https://groups.google.com/forum/%23!topic/comp.os.msdos.apps/oQmT4ETcSzU |archive-date=2017-11-18}}</ref> <ref name="Hall_History">{{cite web |author-first=James F. |author-last=Hall |author-link=Jim Hall (computer programmer) |url=http://www.freedos.org/freedos/about/ |title=History of FreeDOS |work=freedos.org |access-date=2007-05-28 |url-status=dead |archive-url=https://web.archive.org/web/20070527173146/http://www.freedos.org/freedos/about/ |archive-date=2007-05-27}}</ref> <ref name="Hall_2002_History">{{cite web |author-first=James F. |author-last=Hall |author-link=Jim Hall (computer programmer) |date=2002 |url=http://www.freedos.org/freedos/news/press/2002-fsm.txt |title=An Overview of FreeDOS |work=freedos.org |access-date=2011-11-23 |url-status=live |archive-url=https://web.archive.org/web/20171118004236/http://www.freedos.org/technotes/press/2002-fsm.txt |archive-date=2017-11-18}}</ref> <ref name="Villani_2011_Stepdown">{{cite web |author-first1=Pat |author-last1=Villani |author-link1=Pat Villani |orig-year=2011-04-17 |author-first2=James F. |author-last2=Hall |author-link2=Jim Hall (computer programmer) |date=2011-04-22 |title=Need help with project coordinator role |url=https://sourceforge.net/p/freedos/mailman/message/27372423/ |work=freedos-kernel@lists.sourceforge.net |access-date=2022-08-21}}</ref> <ref name="Villani_2011_Obit1">{{cite web |title=Obituary for Pasquale Villani |url=http://obitsforlife.com/obituary/398513/Villani-Pasquale.php |access-date=2011-11-21 |url-status=live |archive-url=https://web.archive.org/web/20171118004501/https://obittree.com/obituary/398513/Villani-Pasquale.php |archive-date=2017-11-18}}</ref> <ref name="Pat_Villani_Homepage_Bio">{{cite web |title=Bio |author-first1=Pat |author-last1=Villani |author-link1=Pat Villani |url=http://www.opensourcedepot.com/user_pages/railroad.html |access-date=2012-03-27 |url-status=dead |archive-url=https://web.archive.org/web/20120215121132/http://www.opensourcedepot.com/user_pages/railroad.html#bio |archive-date=2012-02-15}} </ref> <ref name="Unigroup_2000_News">{{cite web |title=Unigroup of New York November 2000 Announcements |url=http://www.unigroup.org/unigroup-unilist-0011.html |access-date=2011-11-23 |url-status=live |archive-url=https://web.archive.org/web/20171118004609/http://www.unigroup.org/unigroup-unilist-0011.html |archive-date=2017-11-18}}</ref> <ref name="Villani_2011_DEC">{{cite journal |title=Obituaries and memorials for former Digital employees |journal=DECconnection |url=https://decconnection.org/memorials.htm|access-date=2022-08-21}}</ref> <ref name="Villani_2011_Obit2">{{cite web |title=Obituary for Pasquale Villani - In Memory of Pasquale Villani 1954-2011 |url=https://cmfh.frontrunnerpro.com/book-of-memories/943473/Pasquale-Villani/obituary.php|access-date=2022-08-21}}</ref> }}
== External links == * {{webarchive |url=https://web.archive.org/web/20120326012413/http://www.opensourcedepot.com/user_pages/ |date=2012-03-26 |title=Pat Villani's homepage}} * [https://sourceforge.net/projects/dos-c/ Original DOS-C GPLed release on SourceForge] * {{webarchive |url=https://web.archive.org/web/20120116182229/http://opensourcedepot.com/DOS/DOS-C.html |date=2012-01-16 |title=DOS-C page}} * [http://www.freedos.org/ The FreeDOS project]
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{{DEFAULTSORT:Villani, Pat}}
Category:1954 births Category:2011 deaths Category:Free software programmers Category:American computer programmers Category:FreeDOS people Category:People from Brooklyn Category:American people of Italian descent Category:People from Nocera Inferiore Category:Polytechnic Institute of New York University alumni Category:Brookdale Community College faculty Category:Kernel programmers