[cctalk] Re: RS232 then and now

Long before flash drives were a reality,there were Philips cassette-tape based paper tape emulators. I owned a dual-drive one from Techtran. It had the advantage of being able to do high-speed searches and make fast tape-to-tape copies. The commercial embroidery world, like the CNC world was largely paper-tape based. Eventually, there were not only tape-based emulators, but also floppy disk-based ones. Paper tape eventually succumbs to aging and mechanical stress, is difficult to edit and is very low density. One can see the advantage of using later media to accomplish the same end. As far as RS232 and history, I submit that current-loop has more of a place in telegraphy, as it's far more suited to long distances and is less susceptible to signal noise. Many early 1970s serial interfaces offered the choice between 20ma or 60ma current loop or RS232C. --Chuck