HACKER Q&A
📣 andrewstuart

Does anyone know of the whereabouts of the source code of FlexOS/386?


My goal is to get FlexOS open sourced. - Does anyone know of a copy of the source code? I contacted the designer and author of much of FlexOS and he does not know where the source code is.I think it would be fun to see if FlexOS/386 can be brought back to life.

FlexOS was a powerful and innovative operating system from Digital Research, the early 1990's.

Here is a Byte Magazine review of it from back then: https://raw.githubusercontent.com/bootrino/vintage_software/master/1991_01_BYTE_FLEXOSS_MUSCLE.pdf

Here's the Wikipedia article: https://en.wikipedia.org/wiki/FlexOS

Maybe someone at WindRiver knows where the source code of FlexOS is? The wikipedia article above says:

>>>>When Novell decided to abandon further development of the various Digital Research operating systems such as Multiuser DOS (a successor to Concurrent DOS) and Novell DOS (a successor to DR DOS), they sold FlexOS off to the Santa Clara, California-based Integrated Systems, Inc. (ISI) for US$3 million in July 1994.[22] The deal comprised a direct payment of half this sum as well as shares representing 2% of the company. The company already had pSOS+, another modular real-time multitasking operating system for embedded systems, but they continued to maintain FlexOS as well.[22] FlexOS version 2.33 was current as of May 1998 and with FlexOS 2.34 to be released soon after with added support for faster CPUs, 64 MB of memory, EIDE and ATAPI CDROM drives.

>>>>Integrated Systems was bought by their competitor Wind River Systems in February 2000.

  👤 kochbeck Accepted Answer ✓
I notice IBM was a major licensee. If you can figure out which product it was used in, the successor to that division (since I suspect it was something that’s now dead like PSP or mass storage) almost certainly has a clean copy of the source that’s been indexed on a mainframe tape wherever that program group’s library is now archived. It was a massive PITA to go on that sort of hunt when we HAD 3270s on our desks, so I can’t imagine what kind of untoward favors you’d have to offer IT to find it now. But unless decades of archival policies were rolled back, is there somewhere. Look for a product they sold to the federal government. They’re probably still supporting it.
👤 jacquesm
I've tried something similar for another operating system and it did not work out. Just to get an answer from the rights holders was a real challenge. I wish you much good luck. There ought to be some kind of software abandonment law to allow people to salvage software that is no longer in maintenance or that can't be bought.
👤 jonjon10002
It's also worth noting that Wind River purchased Integrated Systems almost entirely so they could kill off pSOS and drive customers to using their competing VxWorks RTOS. I wouldn't doubt if FlexOS is in a similar situation.

It's very likely if you talked to someone at Wind River, they would say "why would you want to release FlexOS for free when you could license VxWorks for a large price instead?"

👤 bragr
Just my two cents: but this seems like an extremely uphill battle without an internal champion. I'd guess with how old this is and how many hands it has passed through, the legal team would struggle to put together the chain of agreements and paperwork to prove they have the sufficient rights to open source it. I don't seem them touching this without doing that first which makes it seem pretty much like a non-starter. I'd focus on trying to track down potential high ranking champions if you want to have any shot.
👤 jonjon10002
Wind River just got bought by Aptiv, like literally a week ago.
👤 mrlonglong
Might I suggest decompiling or disassembling the binaries to generate the sources. It's very time consuming but might be the only way to recover the sources if they are indeed lost.

It's been done in the past to recover lost sources.

👤 andrewstuart
Does anyone here on HN know someone at WindRiver who might know more about FlexOS?
👤 dfawcus
I had the impression that Intel owned the assets now.

While the current / last version would be interesting, it would also be useful to have the source for at least one old version - that before it was rebranded FlexOS and was still Concurrent DOS 286.

Specifically so that code for their 286 based DOS VM could be inspected.

Or possibly the version corresponding to the manuals available on BitSavers, as that appears to still have the code present.

http://bitsavers.org/pdf/digitalResearch/flexos/

👤 rzzzt
WinWorld has DOS Plus and Concurrent DOS from DR, maybe you could ask the maintainers or forum dwellers there.

I found exactly one post on the forum, listing various finds from eBay, that says "Digital Research - FlexOS 386 System Builder's Kit, Release 1.42, 1988 - 5 Box"; unfortunately the linked item is gone by now: https://forum.winworldpc.com/discussion/comment/164410#Comme...

👤 yjftsjthsd-h
> My goal is to get FlexOS open sourced. - Does anyone know of a copy of the source code

That's not enough; you need to find who owns the copyright.

👤 mikewarot
Have you contacted Wind River Systems about it yet? You really need permission from them to make this happen.
👤 Sunspark
Why do you want the source code open sourced?

This product was last released 23 years ago. What would you gain today from having access to the source code?