>Message: 26 >Date: Sat, 1 Feb 2025 18:13:17 -0500 >From: Nigel Johnson Ham <g4a...@gmail.com> >Subject: [cctalk] Re: RS232 then and now > >On 2025-02-01 18:11, Chuck Guzis via cctalk wrote: >> One mystery to me was why did the industry stick with the EIA-232 levels >> for terminals and whatnot long after differential EIA-422 was >> introduced. Higher-speed, better noise immunity, single-ended power >> supply... Seems that the popular places were Appletalk and ST506 data >> lines. But not on DTE/DCE. If you were using full-voltage (±15-±25) >> at high speeds (>500Kbps), the slew rates were ridiculous. >> >> Inertia? My old 80286 motherboard had junper-selectable 232 or 422. >> >> Still have a couple of tubes of 422 drivers/receivers. >> >> --Chuck >> >DEC had RS422 available on their DLJ11J four-port interface, but I never >saw it used in the field. >
The Otrona Attache has two serial ports, DA-15 female, that are jumper selectable between RS-232C, RS-422 or RS-423. Bob
