what is this NCR modem? what did it go to?

Alan Frisbie Flash688 at flying-disk.com
Mon Nov 27 13:15:58 CST 2017

COURYHOUSE at aol.com wrote:

> what is this  NCR   modem? what  did it   go  to?
> NEW Vintage 1971 NCR Acoustic Coupler Modem, NOS, Factory Boxed, C260-400
> / F01   132411929563  on the bay

It is a Bell 103A compatible modem (110 or 300 baud) used with the NCR 260
series of thermal printing terminals.   The 260 came in several variants:
-1 (receive only), -2 (keyboard send/receive), -6 (Automatic (cassette tape)
send/receive).   I worked with them at NCR in 1973 and 74.   I still have
the manuals, and just a few days ago scanned them for Bitsavers.   If you
need a copy I can send you the raw TIFF files (one per page).

Both the -400 and -500 were EIA I/O to the terminal.  The C260-400 connected
to a Bell System DAA (Data Access Arrangement), while the C260-500 was an
acoustic coupler.   The acoustic coupler had a solenoid that would would
automatically raise and lower the handset on the telephone!

Back in those days you could not connect anything directly to the telephone
lines -- you had to use the telco-supplied DAA (kaching!) or an acoustic
coupler.   I don't know if this modem can be connected directly to a phone
line without a DAA.

I think the asking price is totally unrealistic unless you are a rabid
collector of NCR gear.

Alan Frisbie

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