Thanks all for the great input. I replaced line editing code for the time being with a one-liner to get the Unix input, and of course it works ok. I'll replace this with my own line editor some time later  ;)

Paul

Paul Riley



On Sun, 26 Jul 2020 at 09:10, Random832 <random832@fastmail.com> wrote:
On Sat, Jul 25, 2020, at 11:31, Richard Salz wrote:
> Wasn't there an issue that v7 atty used stdin and BSD used stdout?

v7 uses stdout, but system iii and v use stdin. oddly enough, later research unix appears to unconditionally open /dev/tty, making the redirection trick entirely unavailable.