Ward Christensen
Ward Christensen | |
|---|---|
| Born | Template:Birth date West Bend, Wisconsin, U.S. |
| Died | October 11, 2024 (aged 78) Rolling Meadows, Illinois, U.S. |
| Occupation | Computer scientist |
| Known for | Inventing the XMODEM file transfer protocol, co-founding CBBS bulletin board system |
Ward Leon Christensen (October 23, 1945 – October 11, 2024) was a prominent American computer scientist recognized for inventing the XMODEM file transfer protocol and co-founding the pioneering CBBS bulletin board system, which was the first of its kind online.
Early life
Born in West Bend, Wisconsin to Florence (née Hohmann) and Roy Christensen, Ward grew up in a household where his father served as a safety director at West Bend Company and his mother sold World Book encyclopedias. He had one sibling, a brother named Donald Christensen.
During his senior year at West Bend High School in 1963, Christensen constructed a computer that secured first place at a science fair. Following high school, he initially attended the University of Wisconsin–Madison before transferring to Milton College, from which he graduated in 1968 with a Bachelor of Arts degree in physics and chemistry.
Career
Together with Randy Suess and other members of the Chicago Area Computer Hobbyists' Exchange (CACHE), Christensen developed the first-ever BBS amid a Chicago blizzard. This project culminated in the official launch of CBBS on February 16, 1978. CACHE members frequently exchanged software and had long contemplated implementing file transfer capabilities, using the downtime caused by the blizzard to realize this goal.
Christensen began his career at IBM in 1968 as a systems engineer in sales and continued there until his retirement in 2012, concluding as a field technical sales specialist.
A creator of software tools tailored to his own requirements, Christensen developed a cassette-based operating system prior to the widespread adoption of floppy disks and hard disks. After losing source code for some applications, he engineered ReSource, an iterative disassembler for the Intel 8080, to recover it. In 1977, he designed XMODEM, a protocol facilitating file transfers over telephone lines. By 1983, Jerry Pournelle observed that approximately half of the most notable public-domain CP/M software was authored by Christensen. Both Christensen and Suess featured in BBS: The Documentary released in May 2005. Up until his passing, Christensen dedicated time to teaching soldering through Build-a-Blinkie, a non-profit organization conducting "learn-to-solder" workshops across the Great Lakes region.
Personal life
Christensen resided in Dolton, Illinois during the creation of XMODEM in 1977 and co-founding of CBBS in 1978. He passed away at age 78 from a heart attack at his home in Rolling Meadows, Illinois on October 11, 2024. At the time of his death, he was partnered with Debra Adamson and is survived by his brother Donald as well as nieces Carin and Dana Christensen.
Awards
In recognition of his impact on PC telecommunications, Christensen received two Dvorak Awards for Excellence in Telecommunications in 1992, including one honoring lifetime achievement. The following year, he was honored with the EFF Pioneer Award by the Electronic Frontier Foundation for his groundbreaking contributions to digital communications.