Also, in my Tektronix archives... we had an 11/60 with WSC and IIRC Steve Glaser took a stab at moving the CMU stuff. The microengines between the 11/40 and 11/60 were different, so the code had to be rewritten. A big issue, again IIRC, was the microcode compiler/tools for the WSC ran on RSX so it meant UNIX was not running, which was not popular.  

But around the same time, unexpected our group had the chance to get an fairly loaded cast off seperate I/D based 11/70 which had been running RSTS/Cobol for a business support team in sales.    By the time, Steve got anything working on the 11/60, I had the 11/70 (aka "teklabs") up and installed; and I don't remember what happened to the WSC stuff; since we had better solution to small address space problem of adding a '17th address bit' with hardware.

Clem

Clem 

On Fri, Sep 15, 2017 at 8:44 AM, Clem Cole <clemc@ccc.com> wrote:
CMU/CS implemented CSAV and CRET on the 11/40e (6th edition++).  IMO - it was a mixed bag.  I've forgotten the statistics, it was a few ticks fasters for saving the registers, which was good.   The primary thing it did was save a small amount of address space on the non-I/D 40  - which was helpful for applications as they got larger and were running out of address space...... But it was PITA in practice because it meant that binaries compiled on IUS and SUS (the UNIX two systems in CS), would not run anywhere else on campus which were mostly 11/34 or later 11/34A's and it a networked environment (which we were just starting to create) the seams tended to show a little more than we would have liked.

IIRC I eventually got a emulator working at Mellon Institute and EE systems so they binaries would not core dump, but we just recompiled we ran into them. 

The real solution to address space issue was when DEC released the 11/44 which was separate I/D (11/70 class) and the thunk work that we did in 2.9BSD in trying to move 4.1/4.2 code to the 11.

FYI:  Danny Klein and I should have the compiler somewhere (and the microcode) is I ever get my CMU archives off tape.  It's on my list of things to look for.

Clem



On Thu, Sep 14, 2017 at 11:59 PM, Dave Horsfall <dave@horsfall.org> wrote:
On Thu, 14 Sep 2017, Noel Chiappa wrote:

Interesting factoid: The PDP-11 initially used a threaded FORTRAN implementation. In line with the observation above (about a new virtual machine), DEC actually looked into writing microcode for the -11/60 (which had a writeable control store) to implement the FORTRAN virtual machine.

 Did anyone actually use the WCS?  I had visions of implementing CSAV and
CRET on our -60, but never did get around to it.  Too late now...

--
Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will suffer."