[Info-vax] OpenVMS Virtual Terminals (was: Re: DECnet Phase IV broken after VSI update)

[Lawrence D’Oliveiro]

On Monday, November 1, 2021 at 8:18:15 AM UTC+13, Stephen Hoffman wrote:

> Getting ssh and the rest over to its own terminal device name and off 
> FT and/or BG would make the whole thing a shade easier to manage using 
> traditional tools, too. Though I do recall somebody around here has 
> grumbled once or twice about OpenVMS (dis)integration with IP. OpenVMS 
> development had its head... elsewhere and too-long-preferred DECnet and 
> OSI and for way too many years, and the fallout from that era continues 
> to plague us. 

I remember that hoary old RSTS/E had pseudo-keyboards accessible from (privileged) userland processes, odd that VMS never did. Dave Cutler didn’t want to sully his brainchild with such an “inefficient” concept?

Also I remember looking into how SET HOST (the DECnet equivalent of Telnet) worked: once the RTPAD program had set up the connection, all subsequent I/O transfers between the terminal driver and the network connection happened directly in kernel mode, with little or no further intervention from userland. No doubt efficient (at least looking at user-mode CPU usage), but needing a custom kernel-mode driver for each terminal-connection protocol limited your flexibility somewhat.