[Info-vax] C limitations, was: Re: VMS process communication

[John Dallman]

In article <kakr5oFq0fdU8 at mid.individual.net>, bill.gunshannon at gmail.com
(bill) wrote:

> A cute idea, but also a modern accretion. Early C didn't have it
> and as much as people like to say comparing a char to it's numeric
> value is not a good idea it was quite common at one time.  I know,
> because I was the one tasked with porting some of this code to
> Primix where the chars all had a different numeric value.  I don't
> know why they did it, but they did.

Wikipedia reckons <https://en.wikipedia.org/wiki/PRIMOS#Data_access> that
the Teletype ASR-33 required the top bit of an 8-bit byte to be 1. So
that was adopted as the standard PRIMOS character code, since basic ASCII
left the top bit undefined. 

John