Did you know each time you visit the Old-computers
home page, you see a Lear-Siegler ADM-3A terminal...
displaying a READY message and a blinking cursor...
The ADM-3A was one of the first affordable serial
display terminals manufactered by Lear-Siegler,
Inc of Anaheim California.
Why ADM? Nobody knows, maybe American Dream Machine
or Awful Dumb Monitor or Advanced Display Module
or, more seriously, Anaheim Division, Manufacturing...
Why 3A? We know... Because this version quickly
replaced a previous one, called ADM-3, which only
displayed upper-case letters. The 3A version did
not display upper-case letters, but an optional
chip set allows them to be displayed
The product was originally sold in assembled
form for $1,195. A kit version would appear few
months later, at $995. It could be ordered with
a white, green, or amber tube background colour.
The ADM-3A quickly met with great success thanks
to its reliability and low price.
The setup of this 'Dumb machine' (as Lear Siegler
advertised) was done using... 32 dip switches
(!) located at the left of the keyboard. Among
them, 11 was used for the communication rate (from
75 to 19200 bauds), others for parity, display
configuration, character set, etc.
Dennis J. Cagan, co-inventor of this
the ADM-3A terminal, reports :
I just spotted your site
when searching for some info on someone. I noticed
a Lear Siegler ADM-3A video display terminal on
your masthead. Seeing the unit was a thrill. I
was one of the co-inventors of the device - it
was intended to stand for American Dream Machine.
It replaced the LSI 7700A. The ADM-3 itself listed
for $1500 originally.
I was the regional sales
manager for LSI and sold over 90% of the units
sold worldwide from '73-75. I still have the gold
ATMOS clock with a plaque to prove it. The other
3 inventors were engineers. We all I left LSI
in '75 and started SOROC Technology (the only
sign of which is a spin off in Canada www.soroc.com).
The first product from
SOROC was actually a design for a product similar
to the ADM which we sold to Beehive and it became
the B100 in '76-77.