https://en.wikipedia.org/wiki/SunOS#History

The SunOS 3.x => 4.x transition was also the BSD 4.2 => 4.3 transition.

Sun operating system version numbers seemed to parallel the version of Unix it was based on for a while there, until it started spinning out of control and got sucked up into the System V death star. 

Sun UNIX 0.7: UniSoftUNIX v7
SunOS 1.x: 4.1 BSD
SunOS 2.x: 4.2 BSD
SunOS 3.x: 4.2 BSD + some 4.3 BSD and some System V
SunOS 4.x: 4.3 BSD + even more System V 
SunOS 5.0: SVR4

-Don


On 12 Oct 2017, at 17:09, Don Hopkins <SimHacker@gmail.com> wrote:


On 12 Oct 2017, at 16:59, Larry McVoy <lm@mcvoy.com> wrote:

That must have been really early on because by the time I got to Sun (4.0?
Maybe 4.1?) shared libraries worked properly.

Yeah, I remember that being a SunOS 3.x limitation. 4.x was a whole lot nicer! 

Wikipedia says: 

SunOS 4.0: Dec 1988: New virtual memory system, dynamic linking, automounter, System V STREAMS I/O. Sun386i support.

https://en.wikipedia.org/wiki/SunOS#History

Then it all went downhill from thereā€¦ ;(

-Don

http://www.art.net/~hopkins/Don/unix-haters/slowlaris/sunos-died.html

The Day SunOS Died

Lyrics by N. R. "Norm" Lunde.
Apologies to Don McLean.

Remember when those guys out West
With their longish hair and paisley vests
Were starting up, straight out of UCB?
They used those Motorola chips
Which at the time were really hip
And looked upon the world through VME.
Their first attempt ran like a pig
But it was the start of something big;
They called the next one the Sun-2
And though they only sold a few
It soon gave birth unto the new
Sun-3 which was their pride
And now they're singing

[chorus]

"Bye, bye, SunOS 4.1.3!
ATT System V has replaced BSD.
You can cling to the standards of the industry
But only if you pay the right fee -- 
Only if you pay the right fee . . ."

The hardware wasn't all they sold.
Their Berkeley port was solid gold
And interfaced with System V, no less!
They implemented all the stuff
That Berkeley thought would be enough
Then added RPC and NFS.
It was a lot of code to cram
Into just four megs of RAM.
The later revs were really cool
With added values like SunTools
But then they took us all for fools
By peddling Solaris . . .
And they were singing,

[chorus]

They took a RISC and kindled SPARC.
The difference was like light and dark.
The Sun-4s were the fastest and the best.
The user base was having fun
Installing SunOS 4.1
But what was coming no one could have guessed.
The installed base was sound
And software did abound.
While all the hackers laughed and played
Already plans were being made
To make the dubious "upgrade" 
To Sun's new Solaris . . .
And Sun was singing,

[chorus]

The cartridge tapes were first to go --
The CD-ROM's a must, you know
And floppy drives will soon go out the door.
I tried to call and ask them why
But they took away my TTY
And left my modem lying on the floor.
While they were on a roll
They moved the damned Control.
The Ethernet's now twisted pair
Which no one uses anywhere.
ISDN is still more rare -- 
The bandwidth's even less!
But still they're singing

[chorus]

But worst of all is what they've done
To software that we used to run
Like dbx and even /bin/cc.
Compilers now have license locks
Wrapped up in OpenWindows crocks --
We even have to pay for GCC!
The applications broke;
/usr/local went up in smoke.
The features we've depended on
Before too long will all be gone
But Sun, I'm sure, will carry on 
By peddling Solaris,
Forever singing,

[chorus]