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Ward Leon Christensen (October 23, 1945 – October 11, 2024) was an American computer scientist who was the inventor of the XMODEM file transfer protocol and a co-founder of the CBBS bulletin board, the first bulletin board system (BBS) ever brought online.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name="bbs questions"/><ref>Template:Cite news</ref><ref name="Ars Obit">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Early lifeEdit
Christensen was born on October 23, 1945, in West Bend, Wisconsin, to Florence (née Hohmann) and Roy Christensen. His father was a safety director at West Bend Company and his mother sold World Book encyclopedias. Christensen also had a brother, Donald Christensen.<ref name="Metz"/><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Christensen attended West Bend High School. In his senior year of high school in 1963, he created a computer that won first place in a science fair.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> After graduating high school, Christensen attended the University of Wisconsin–Madison before transferring to Milton College.<ref name="Metz">Template:Cite news</ref><ref name="bbs questions"/> He graduated from Milton College with a Bachelor of Arts degree in physics and chemistry in 1968.<ref name="bbs questions">re: R/1ST BBS QUESTIONS (Msg 46394) from Ward Christensen to Steve Culver, July 31, 1993.</ref>
CareerEdit
Christensen, along with collaborator Randy Suess,<ref>Template:Cite news</ref> members of the Chicago Area Computer Hobbyists' Exchange (CACHE), started development of the first BBS during a blizzard in Chicago, Illinois, and officially established CBBS four weeks later, on February 16, 1978. CACHE members frequently shared programs and had long been discussing some form of file transfer, and the two used the downtime during the blizzard to implement it.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite encyclopedia</ref>
In 1968, Christensen was hired by IBM as a systems engineer in the sales office.<ref name="bbs questions"/><ref name="Blinkie"/><ref>Template:Cite book</ref><ref name="Metz"/> Christensen would work for IBM until his retirement in 2012.<ref name="Metz"/> His last position with IBM was a field technical sales specialist.<ref name="Blinkie"/>
Christensen was noted for building software tools for his needs. He wrote a cassette-based operating system before floppy disks and hard disks were common.Template:Citation needed When he lost track of the source code for some programs, he wrote ReSource, an iterative disassembler for the Intel 8080, to help him regenerate the source code.<ref>Template:Cite news</ref><ref>Template:Cite news</ref> In 1977, he wrote XMODEM, a protocol to send computer files over phone lines.<ref name="Metz"/> Jerry Pournelle wrote in 1983 of a collection of CP/M public-domain software that "probably 50 percent of the really good programs were written by Ward Christensen, a public benefactor."<ref name="pournelle198307">Template:Cite news</ref> In May 2005, Christensen and Suess were both featured in BBS: The Documentary.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Christensen taught soldering techniques, until his death, through Build-a-Blinkie, a non-profit organization that hosts "learn-to-solder" events in the Great Lakes area.<ref name="Blinkie">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Personal lifeEdit
Christensen lived in Dolton, Illinois, when he invented XMODEM in 1977 and co-invented CBBS in 1978.<ref name="bbs questions"/><ref name="Metz"/> Christensen died from a heart attack at his home in Rolling Meadows, Illinois, on October 11, 2024, at the age of 78. At the time of his death, he was in a relationship with Debra Adamson. He also left behind his brother, Donald, and his nieces, Carin and Dana Christensen.<ref name="Metz"/><ref name="Ars Obit"/>
AwardsEdit
Christensen received two 1992 Dvorak Awards for Excellence in Telecommunications, one with Randy Suess for developing the first BBS, and a lifetime achievement award "for outstanding contributions to PC telecommunications."<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In 1993, he received the Pioneer Award from the Electronic Frontier Foundation.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>