Nelson H. F. Beebe <beebe@math.utah.edu> wrote:
>
>       % cat *.log | grep '^ char type is' | sort | uniq -c
>           157         char type is          signed
>             3         char type is          unsigned
>
> The sole outliers are
>
>       * Arch Linux ARM on armv7l
>       * IBM CentOS Linux release 7.4.1708 on PowerPC-8
>       * SGI IRIX 6.5 on MIPS R10000-SC

Nice survey, thanks!

I learned C using the Norcroft C compiler on early Acorn / ARM machines
where char was unsigned. That is still the case, though ARM have switched
from Norcroft to clang.

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0774h/kpr1493281322162.html

(And I started learning about unix from reading articles about RISC iX,
Acorn's 4.3BSD port to the Archimedes.)