Oh sure!  I'm having to use my phone...   It's the combined sources here:http://bitsavers.trailing-edge.com/bits/IBM/RT/rt_bsd44/ doc  mk jsteve@localhost:~/rt_bsd4/src/sys/.local/mach2.4$ pwd /home/jsteve/rt_bsd4/src/sys/.local/mach2.4 jsteve@localhost:~/rt_bsd4/src/sys/.local/mach2.4/mk/conf$ cat vers*6951X So 5.1x edit 69 jsteve@localhost:~/rt_bsd4/src/sys/.local/mach2.4/mk$ more CHANGELOGHISTORY 17-May-88 David Golub (dbg) at Carnegie-Mellon University XM21:        David Black completely rewrote the accurate timing code        (which is now implemented on all machines) and the priority        and scheduling algorithms. The system now correctly reports        cpu_usage per thread. The all file has this before i386 was added.  So it's an older v2 than what is on the CSRG CD, but not as old as the VAX '86 stuff.  It seems to be March 11 1989, although that could be when this was either archived or ported..  I guess they didn't exactly sync to a public kernel tree all that often.  On Tue, Feb 18, 2020 at 4:05 PM +0800, "Kevin Bowling" wrote: I’m asking exactly where the Mach is in the linked archive. VRM, AIX or AOS? Can you support this with a reference for my own documentation On Tue, Feb 18, 2020 at 1:02 AM Jason Stevens wrote: It's the CMU micro kernel.  The hybrid "2.6" lived on in NeXTSTEP, and OPENSTEP, with various upgrades to bring it up to OS X.  The RT as I understand it was a research machine, hence the BSD ports, and Mach port.  What is interesting the more I dig around is that there was ROMP coprocoessor cards, and an OS/2 and DOS monitor program to let you boot BSD on the card.  Peripheral IO was done on the x86 side.  If RT's are rare, I can't imagine how impossible it would be to get one of those cards!  The BSD assembler and linker source is in the archives too, no doubt it'll help someone make a RT emulator.  Get Outlook for Android On Tue, Feb 18, 2020 at 12:54 PM +0800, "Kevin Bowling" wrote: Can you clarify what is Mach in this archive if I have a gap in my knowledge? I didn’t know the VRM had any direct relationship to Mach Regards,Kevin On Mon, Feb 17, 2020 at 9:43 PM Jason Stevens wrote: Interesting stuff!  And another version of Mach is buried in there.  So the 4 csrg cd set may have updates to the romp support as it's an older version of the 5.1 kernel from 89...  Not that think there is any Mach romp users.  Get Outlook for Android From: TUHS on behalf of Charles H Sauer Sent: Tuesday, February 18, 2020, 5:51 a.m. To: TUHS Subject: [TUHS] Bitsavers' RT/PC, AIX, AOS, etc. recent additions The Bitsavers' RSS feed (http://user.xmission.com/~legalize/vintage/bitsavers-bits.xml) seemed to me to be dominated by RT, AIX, AOS (BSD for RT), etc. stuff in the last week or so. I've only sampled a few items, but discovered a few things that I should have known (or knew and forgot?) while I was at IBM. http://www.bitsavers.org/pdf/ibm/pc/rt/ -- voice: +1.512.784.7526 e-mail: sauer@technologists.com fax: +1.512.346.5240 Web: https://technologists.com/sauer/ Facebook/Google/Skype/Twitter: CharlesHSauer