Unix History

[guy at sun.UUCP]

> I don't know much about the version of PWB UNIX that was released
> externally, but I think that predated UNIX/TS 1.0 significantly, so there
> were probably UNIX/TS 1.0 features not in the external version of PWB UNIX,
> as well as vice versa.

The PWB/UNIX that was released externally was PWB/UNIX 1.0, which was a
V6-flavored system, rather than a V7-flavored system like the UNIX/TS line.

> Most new features made it to the PDP11.  The major exception is the news
> object module format, which makes SDB possible.  SDB is a UNIX 3.0 feature
> which did not make it to the PDP11.  The UNIX 4.0 and UNIX 5.0 releases
> for the PDP11 were pretty complete.

No; 3.0 had an object file format of the same flavor as that used by
Research UNIX, and it supported "sdb" by adding the N_STAB symbol table
entry type to hold debugger information.  The way the N_STAB symbols were
used, however, didn't support the new rules for structure member names, and
didn't support some other things.  The COFF debugger symbols do, so "sdb"
was fixed to support them.

I suspect the PDP-11 didn't support "sdb" either because 1) nobody bothered
changing the Ritchie compiler to generate N_STAB entries or 2) there wasn't
enough address space to support it.
-- 
	Guy Harris
	{ihnp4, decvax, seismo, decwrl, ...}!sun!guy
	guy at sun.com (or guy at sun.arpa)