And many printers had an option to go either RS232 or current loop.

Nick D.
----------
> From: WirtAtmar <[log in to unmask]>
> To: [log in to unmask]
> Subject: Re: non-HP terminals
> Date: Tuesday, April 07, 1998 6:14 PM
>
> Bruce Toback writes:
>
> > Wirt Atmar writes:
> >
> >  >you could actually hook up an old
> >  >KSR 33 or 35 teletype to a DTC if it still supported 110 baud.
Otherwise,
> >  >nothing's changed about basic terminal serial connections in 40
years.
> >
> >  Not quite: I'm not sure when EIA RS-232 was promulgated, but I'm
pretty
> >  sure it was around 1960.
>
> Bruce is right. I've told myself a million times: "Self, never
exaggerate,"
> but I still don't listen. It has only been 38 years, not 40, as I stated.
>
>
>
> >  Prior to RS-232 -- and for quite some time
> >  afterward -- most terminal serial connections used a 20ma or 60ma
current
> >  loop.
>
> John Korb wrote privately and pointed out the same thing. He also pointed
out
> that current loop to voltage converters were available during the
conversion
> period to RS-232.
>
> Wirt Atmar