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SDF Public Access Unix System
open-in-new
<h2 id="services">Services</h2> <p>SDF provides free <a href="/facts/Unix_shell/2G4T2Fb9">Unix shell</a> access, <a href="/facts/World_Wide_Web/wvnTrWFq">web</a> hosting and many other features at the user membership level. Additional programs, capabilities and resources are available at "patron" and "sustaining" level memberships, which are granted with one-time or recurring dues in support of the SDF system. </p><p>The SDF network of systems that serves its membership currently includes <a href="/facts/NetBSD/PTm5HWls">NetBSD</a> servers for regular use (running on <a href="/facts/DEC_Alpha/4eN7LuXG">DEC Alpha</a>- and <a href="/facts/Opteron/IF1ueyIJ">AMD Opteron</a>-powered hardware) as well as <a href="/facts/Retrocomputing/fHu2QnUo">retrocomputing</a> environments: a <a href="/facts/TOPS-20/uBCxEqk9">TWENEX</a> system running the Panda Distribution TOPS-20 MONITOR 7.1 on two <a href="/facts/XKL/kNtzL8vt">XKL</a> TOAD-2 computers,<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a><a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> a <a href="/facts/Symbolics/U8cJjbwb">Symbolics</a> <a href="/facts/Genera_(operating_system)/XyVHB8VP">Genera</a> system, and an <a href="/facts/Incompatible_Timesharing_System/SMuAEgUx">ITS</a> system<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> </p><p>SDF also hosts its own instances of <a href="/facts/Social_media/kUIkfpIA">social media</a> websites from the <a href="/facts/Fediverse/fIBCh4ya">fediverse</a>, including a <a href="/facts/Mastodon_(software)/paYlaPlI">Mastodon</a> microblogging service,<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> a <a href="/facts/Pixelfed/LwNANI38">Pixelfed</a> image sharing service,<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> and a <a href="/facts/Lemmy_(software)/LHDBHYAb">Lemmy</a> link aggregator with discussion.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> In addition, SDF hosts a <a href="/facts/Matrix_(protocol)/nV0oNTsr">Matrix</a> chat server.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> </p> <h3>Free Membership Services</h3> <p>SDF provides free Unix shell access and web hosting to its users. In addition, SDF provides increasingly rare services such as <a href="/facts/Dial-up_Internet_access/gfhNU9s3">dial-up internet access</a>, and <a href="/facts/Gopher_(protocol)/G2bpDRQJ">Gopher</a> hosting. SDF is one of very few organizations in the world still actively promoting the gopher protocol,<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a><a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> an alternate protocol that existed at the introduction of the modern World Wide Web.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> </p><p>The system contains thousands of programs and utilities, including a <a href="/facts/Command-line_interface/R9JpGmXQ">command-line</a> BBS called BBOARD,<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> a chat program called COMMODE,<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> email programs, webmail, social networking programs, developer tools and games. Most of the applications hosted at SDF are accessed via the command-line, and SDF provides K-12 and college classrooms the free use of computing resources for Unix education.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> </p><p>SDF also supports multiple retrocomputing experiences, including free user accounts on <a href="/facts/TOPS-20/uBCxEqk9">TOPS-20</a> and <a href="/facts/Genera_(operating_system)/XyVHB8VP">Symbolics Genera</a> operating systems that are running live and accessible via the internet. </p> <h3>Dues-paying membership services</h3> <p>There are additional services that are made available on SDF systems to users who apply to be "patrons" and pay one-time dues of US$36 for "Lifetime Membership", and still more services available for at US$9/quarter "sustaining membership", including services such as <a href="/facts/Nextcloud/4dCYj8W0">NextCloud</a>, and access to a large disc-array server. At the sustaining membership level, members are authorized to validate new users to SDF's free User level of membership (otherwise, new members may submit US$1 to be validated). </p><p>There are also specialized privileges which patron and sustaining level users can obtain to gain access to particular technologies, including <a href="/facts/Electronic_mailing_list/JfLtS62I">mailing lists</a>, <a href="/facts/Voice_over_IP/5QGBbXYg">Voice-over-IP</a>, <a href="/facts/Database/VYcpkevb">Databases</a>, Virtual Private Network <a href="/facts/Virtual_private_network/HX1WUQ3E">(VPN)</a>, and <a href="/facts/Domain_registration/sv0v6nU6">Domain registration</a>. </p> <h2 id="history">History</h2> <p>In 1987, Ted Uhlemann started SDF on an <a href="/facts/Apple_IIe/3LMaIspU">Apple IIe</a> <a href="/facts/Microcomputer/ETW22UTv">microcomputer</a> running "Magic City Micro-BBS" under <a href="/facts/Apple_ProDOS/51vuP5te">ProDOS</a>. The system was run as a "Japanese Anime <a href="/facts/Special_interest_group/FGwon2J1">SIG</a>" known as the SDF-1. In 1989, Uhlemann and Stephen Jones operated SDF very briefly as a <a href="/facts/Citadel_(software)/oNuM0E7q">DragCit Citadel BBS</a> before attempting to use an Intel x86 UNIX clone called <a href="/facts/Coherent_(operating_system)/0N5lb15h">Coherent</a>. </p><p>Unhappy with the restrictive menu driven structure of existing BBS systems, Uhlemann, Jones and Daniel Finster created a <a href="/facts/UNIX/0pNL2seI">UNIX</a> <a href="/facts/UNIX_System_V/Epm6GEY4">System V</a> BBS in 1990, initially running on an <a href="/facts/IA-32/7yTv1aHH">i386</a> system, which later became an <a href="/facts/3B_series_computers/vVlYEurp">AT&T 3B2</a>/400 and 500, and joined the lonestar.org <a href="/facts/UUCP/dQ055F7b">UUCP</a> network. Three additional phone lines were installed in late 1991. </p><p>In the fall of 1992, Uhlemann and Finster left SDF to start one of the first commercial <a href="/facts/Internet/Xw1rVvJU">Internet</a> companies in Texas, Texas Metronet. </p><p>SDF continued to grow, expanding to ten lines in 1993 along with a <a href="/facts/Serial_Line_Internet_Protocol/oqUaoA0f">SLIP</a> connection provided by cirr.com. UUCP was still heavily relied upon for <a href="/facts/Usenet/lYJWFBR6">Usenet</a> news and email. </p><p>In 1997, SDF (then with about 15,000 users) migrated to <a href="/facts/Linux/9FvCKSTq">Linux</a>. The migration to Linux marked a turning point, as the system started coming under attack like it never had before in its history. Jones calls the Linux period <i>the dark age</i>. </p> <p> In part due to the number of attacks undertaken by malicious users against SDF, the years 2000 and 2001 saw SDF migrate from Linux to <a href="/facts/NetBSD/PTm5HWls">NetBSD</a> and from Intel <a href="/facts/X86/Kypq5fgu">x86</a> to <a href="/facts/DEC_Alpha/4eN7LuXG">DEC Alpha</a>. This migration included relocation of the servers from <a href="/facts/Lewisville%2c_Texas/IjTQNtKk">Lewisville, Texas</a> to <a href="/facts/Seattle/7lYIrCa6">Seattle</a>, <a href="/facts/Washington_(state)/7tCrTFnN">Washington</a>. The Linux system was officially decommissioned on August 17, 2001. The occasion was captured in a <a href="http://bch.sdf.org/bye-bye-leenox.htm">COMMODE Log</a> preserved by one of SDF's users.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> (COMMODE is a <a href="/facts/TOPS-20/uBCxEqk9">DEC TOPS-20</a> <a href="/facts/Online_chat/UXwSoP4j">chat system</a> ported by Jones to <a href="/facts/Unix/0pNL2seI">Unix</a> as an executable <a href="/facts/KornShell/MMp8fQ4A">KornShell</a> script.) </p><p>Although SDF Public Access UNIX System was registered as an operating business in 1993 according to the Dallas County Records Office, it wasn't until October 1, 2001, that the SDF Public Access UNIX System was formed as a <a href="/facts/Delaware/4n4I3Rhu">Delaware</a> not-for-profit corporation and subsequently granted <a href="/facts/501(c)(7)/Qx1XrC9t">501(c)(7)</a> non-profit membership club status by the <a href="/facts/Internal_Revenue_Service/GBdRoslU">IRS</a>.<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> SDF had operated under the auspice of the MALR corporation between 1995 and 2001. </p><p>As of May 2016<a href="https://en.wikipedia.org/w/index.php?title=SDF_Public_Access_Unix_System&action=edit">[update]</a>, SDF was composed of 47,572 users from around the world. SDF users include engineers, computer programmers, students, artists and professionals. </p><p>SDF.org is a development site for <a href="/facts/NetBSD/PTm5HWls">NetBSD</a>, and in 2018, SDF was the largest NetBSD installation in the world.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> </p> <h2 id="further-reading">Further reading</h2> <ul><li>Sterling, Bruce (1992). <i><a href="/facts/The_Hacker_Crackdown/7Qjpn7I9">The Hacker Crackdown</a> : Law and Disorder on the Electronic Frontier</i>. New York: <a href="/facts/Bantam_Books/uFxsmguL">Bantam Books</a>.</li></ul> <h2 id="external-links">External links</h2> <ul><li><a href="http://sdf.org/">Official website</a> </li> <li><a href="https://twitter.com/sdf_pubnix">@sdf_pubnix on twitter</a></li> <li><a href="http://bsdtalk.blogspot.com/2006/03/bsdtalk021-interview-with-stephen.html">Interview with Stephen Jones at bsdtalk (MP3)</a></li> <li><a href="https://web.archive.org/web/20160419052745/http://www.vintage.org/gallery.php?grouptag=VCF60">Vintage Computer Festival SDF Exhibit</a> at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a> (archived 19 April 2016)</li> <li><a href="https://www.npr.org/2012/04/17/150817325/in-noisy-digital-era-elegant-internet-still-thrives">2012 Feature Story on NPR, "In Noisy Digital Era, 'Elegant' Internet Still Thrives"</a></li> <li><a href="https://archive.org/details/BBS.The.Documentary">BBS: The Documentary</a> at the <a href="/facts/Internet_Archive/PHStU8Lo">Internet Archive</a></li> <li><a href="https://www.netbsd.org">NetBSD Project Web Site</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"PUBNIX-System SDF-1 feiert 20-jähriges Jubiläum | heise Netze". Heise.de. 18 June 2007. Retrieved 2014-05-09. <a href="http://www.heise.de/netze/meldung/PUBNIX-System-SDF-1-feiert-20-jaehriges-Jubilaeum-140770.html" target="_blank">http://www.heise.de/netze/meldung/PUBNIX-System-SDF-1-feiert-20-jaehriges-Jubilaeum-140770.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"Twenex Public Access System". Twenex. Retrieved 8 January 2017. <a href="http://www.twenex.org/?network" target="_blank">http://www.twenex.org/?network</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>"Twenex History". Twenex. Retrieved 11 October 2021. <a href="http://twenex.org/?history" target="_blank">http://twenex.org/?history</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>"Home". hactrn.org. <a href="http://hactrn.org/" target="_blank">http://hactrn.org/</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>"Mastodon at SDF". mastodon.sdf.org. Retrieved 10 June 2023. <a href="https://mastodon.sdf.org" target="_blank">https://mastodon.sdf.org</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>"Pixelfed at SDF". pixelfed.sdf.org. Retrieved 10 June 2023. <a href="https://pixelfed.sdf.org" target="_blank">https://pixelfed.sdf.org</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>"Lemmy at SDF". lemmy.sdf.org. Retrieved 10 June 2023. <a href="https://lemmy.sdf.org" target="_blank">https://lemmy.sdf.org</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>"matrix.sdf.org/". matrix.sdf.org. Retrieved 26 June 2023. <a href="https://matrix.sdf.org" target="_blank">https://matrix.sdf.org</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>"Welcome to Floodgap Systems' official gopher server". Floodgap Systems. Cameron Kaiser. Retrieved 6 July 2020. <a href="http://gopher.floodgap.com/gopher/gw" target="_blank">http://gopher.floodgap.com/gopher/gw</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>"Official Site of the Internet Gopher Club Underground Syndicate". Phlogosphere.org. SDF Public Access Unix. Retrieved 11 August 2020. <a href="http://gopher.floodgap.com/gopher/gw?gopher://gopher.club" target="_blank">http://gopher.floodgap.com/gopher/gw?gopher://gopher.club</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>"Where have all the gophers gone?". University of Michigan School of Information. Christopher (Cal) Lee. Retrieved 8 January 2017. <a href="https://ils.unc.edu/callee/gopherpaper.htm" target="_blank">https://ils.unc.edu/callee/gopherpaper.htm</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>"BBOARD command line BBS". SDF.org. SDF. Retrieved 8 January 2017. <a href="http://sdf.org/?tutorials/bboard-tutorial" target="_blank">http://sdf.org/?tutorials/bboard-tutorial</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>"COMMODE on SDF". SDF.org. Retrieved 8 January 2017. <a href="http://sdf.org/?tutorials/comnotirc#whatis" target="_blank">http://sdf.org/?tutorials/comnotirc#whatis</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>"SDF Public Access UNIX System - Free Shell Account and Shell Access". Sdf.org. Retrieved 6 July 2020. <a href="http://sdf.org/?join" target="_blank">http://sdf.org/?join</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>"pooderNet: bye-bye-leenox". Bch.sdf.org. Retrieved 2014-05-09. <a href="http://bch.sdf.org/bye-bye-leenox.htm" target="_blank">http://bch.sdf.org/bye-bye-leenox.htm</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>"Details about SDF Public Access UNIX System". Internal Revenue Service. Retrieved 2021-08-15. <a href="https://apps.irs.gov/app/eos/detailsPage?ein=800016172&name=SDF%20PUBLIC%20ACCESS%20UNIX%20SYSTEM%20INC&city=&state=&countryAbbr=US&dba=&type=COPYOFRETURNS&orgTags=COPYOFRETURNS" target="_blank">https://apps.irs.gov/app/eos/detailsPage?ein=800016172&name=SDF%20PUBLIC%20ACCESS%20UNIX%20SYSTEM%20INC&city=&state=&countryAbbr=US&dba=&type=COPYOFRETURNS&orgTags=COPYOFRETURNS</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>"What's in store for NetBSD 9.0" (PDF). The NetBSD Project. Sevan Janiyan. 22 September 2018. Retrieved 6 July 2020. <a href="https://www.netbsd.org/gallery/presentations/sevan/eurobsdcon2018.pdf" target="_blank">https://www.netbsd.org/gallery/presentations/sevan/eurobsdcon2018.pdf</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> </ol>