On 2015-09-23 16:43, Paul Koning wrote:

On Sep 23, 2015, at 10:30 AM, Jay Jaeger <cu...@charter.net> wrote:

On 9/23/2015 9:10 AM, Mouse wrote:
I am 100% certain, for example, that it would be possible to come up
with a C compiler for a 40K IBM 1410, which is in the set you
describe.

Possible?  Sure.  But it would be difficult; you would need to simulate
a binary machine - C has a whole bunch of stuff that is defined to
operate "as if" certain things are stored in binary.

Worse yet, two's complement binary.  At least nowadays.  Which makes me suspect 
that there had to be some shortcuts taken when C was implemented on the CDC 
6000 series.

(Interestingly enough, if you ignore that little detail, it isn't terribly hard 
to write the skeleton of a 6000 code generator back-end for GCC...)

As far as I can remember, the C standard still do not require that the computer uses two complement. So you can actually get away with a C compiler that uses one complement. But much actual code will probably break, because they make way more assumptions than the standard actually provide...

        Johnny

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