[TUHS] Was pcc ever ported to the CDC6600?

Lorne Wilkinson lrw at acm.org
Sun Jan 22 00:42:22 AEST 2017

Control Data had a lab in Mississauga On, (outside of Toronto) in the 70s
and 80s where some of the CDC Cyber 180s were designed and built.

A company called HCR Corp in Toronto did a considerable amount of work for
CDC re-targeting pcc and UNIX System V for the 180s and ETA10.

I was fortunate enough to work for both companies. I didn't work on the pcc
port to the Cyber 180, but some of the UNIX port. I thought the Cyber 180
architecture was way ahead of it's time. Virtual memory, 64-bit ints,
shared libraries. Some of the 180s were also dual-state, NOS/VE 64-bit OS
and apps 50% of the time, a CPU microcode switch, to NOS and the 60-bit
platform for 50% of the time, to support NOS to NOS/VE migration. Pcc
re-targeting was challenging in a number of ways, addresses were 48 bits,
with a ring and segment number, which resulted in a NULL pointer actually
not being 0.

HCR also did work on the ETA10 UNIX port, I didn't participate on that
project, but HCR also re-targeted pcc for the Intel iWarp CPU, which I
worked on. HCR had a portable global code optimizer and peephole optimizer
for pcc, so much of the work involved splitting pcc, for the global
optimizer, to operate between front and back ends, and integrating the
peephole optimizer, re-targeting the code generator, and tuning.

A lot of very smart people who were great to work with at CDC and HCR,
certainly a great way to start my career.

Some more background here on the CYBERs


I seem to remember reading a number of those manuals 30 years ago or so.

And info on the iWarp project:


On Sat, Jan 21, 2017 at 7:51 AM, Kay Parker <kayparker at mailite.com> wrote:

> > My memory of the Kyber (as we called them; we had a 72)
> wasn't it a CDC Cyber?
> https://en.wikipedia.org/wiki/CDC_Cyber
> On Sat, Jan 21, 2017, at 04:38 AM, Dave Horsfall wrote:
> > On Thu, 19 Jan 2017, Steve Johnson wrote:
> >
> > > PCC ended up being ported to many dozen different architectures, so
> it's
> > > quite possible, but I don't recall it being done.  It was kind of a
> > > dinosaur by the early 70's.  I'm not even sure that it had memory
> > > protection, and it certainly didn't have paging.  And the I/O system
> was
> > > strange.  So porting Unix would have been next to impossible.
> >
> > My memory of the Kyber (as we called them; we had a 72) was that it was
> > not character-addressable, but 60-bit word-addressable, thus making
> > string
> > handling somewhat difficult.  Don't get me started on its utterly broken
> > architecture...  I have thankfully lost my programming manual for the
> > beast.
> >
> > > The main thing I remember about the 6600 was that it didn't have parity
> > > bits on its memory.  So people used to run the same program three times
> > > and if two of the answers agreed, they published...
> >
> > Parity only slowed it down, and besides, hardware never failed...
> >
> > My fondest memory of the thing was its command completion; I would start
> > to type "O, TR" and it would fill out "O, TRANSACTION TERMINAL STATUS".
> > Which reminds me that my worst memory was its console keyboard, with "0"
> > on the left...
> >
> > --
> > Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will
> > suffer."
> --
>   Kay Parker
>   kayparker at mailite.com
> --
> http://www.fastmail.com - Does exactly what it says on the tin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20170121/c74f8a57/attachment.html>

More information about the TUHS mailing list