DRDOS' Bryan Sparks Clarifies Vintage OS CP/M's Status as Open to All to Distribute, Modify

Previously released source code had been ignored by many owing to licensing problems, but a fresh new license should open it to all.

Gareth Halfacree
3 months agoRetro Tech

Bryan Sparks, president of DRDOS and current owner of the rights to the CP/M operating system, has made a welcome clarification to the CP/M license — making sure it's clear that anyone at all has the rights to distribute it, modified or otherwise.

CP/M, originally Control Program/Monitor before being renamed to Control Program for Microcomputers, was a hugely influential operating system in the 1970s and 1980s. Developed by Gary Kildall and commercialized by his company Digital Research, CP/M compatibility was a must-have for minicomputers and microcomputers before the IBM Compatibles began to take hold in the market.

Despite having seen its last official release in 1983, CP/M has a passionate community of users and programmers to this day — but who have been working in a murky legal gray area, following confusion over the legitimacy of compiled and source copies of the software floating around the web.

Bryan Sparks' DRDOS bought what remained of Digital Research in the 1990s, receiving the rights to CP/M along the way. In a gift to the community, the source code for CP/M was publicly released — but many in the community have shied away from it, believing that its use would cause legal problems.

Sparks addressed the problem in 2001 with the promise that the community had "a right to use, distribute, modify, enhance and otherwise make available in a nonexclusive manner the CP/M technology" — but in a twist of phraseology accidentally made the implied license valid only for the "Unofficial CP/M Web Site" and its community.

"That wasn't my intent," Sparks clarified following an email from community member Scott Chapman earlier this month, "but I get that this was unclear. It was also some time ago. Let this paragraph represent a right to use, distribute, modify, enhance, and otherwise make available in a nonexclusive manner CP/M and its derivatives.

"This right comes from the company, DRDOS, Inc.'s purchase of Digital Research, the company and all assets, dating back to the mid-1990s. DRDOS, Inc. and I, Bryan Sparks, President of DRDOS, Inc. as its representative, is the owner of CP/M and the successor in interest of Digital Research assets.

"It's a bit clumsy," Sparks admits of the modified legalese, which removes any mention of a specific website, "but this may get the intent cleared and authority upon which it is granted."

Those looking for Sparks' full email can find it on the Unofficial CP/M Website's License section, while the main site offers the most complete copies of CP/M binaries, source code, emulators, software, and development utilities.

Main article image courtesy Michael Specht, Creative Commons Attribution-ShareAlike 3.0.

Gareth Halfacree
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire: freelance@halfacree.co.uk.
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