[Info-vax] SET TERM /TTSYNC on ancient VMS versions

[Chris]

On 08/16/18 12:35, Johnny Billquist wrote:

> Well, first of all, using modem controls for flow control is an abuse of
> the signals. They were never intended for this. And so DEC did,
> correctly, not use the signals that way.

Dec terminals were 3 wire, rx, tx data and ground, with xon, xoff
flow control capability. VT220 had support for that iirc. Some of
their serial cards had the hardware modem control lines
available in addition to that. Flow control was needed on early
systems to prevent buffer overflow etc, but modern systems can often
run as high as 115k b/s sucessfully with no flow control at all

>
> I'm surprised to hear that DEC did have hardware flow control back
> already in VMS V5. Are you sure about that?

Using modems, flow control was usually done with the modem control lines
rts/cts etc, but both xon/xoff and hardware flow control has been used
all over industry for decades and still is...

Chris