Alpha Microsystems, Inc. was founded in 1977 by Dick Wilcox and Bob Hitchcock, working from the proverbial garage. They still make text terminals and "thin clients" to this day, as well as processor boards and computers that run their own Alpha Micro Operating System, AMOS. Before they made their own terminals, they used to sell Soroc terminals.
Their website at alphamicro.com contains quite a few downloadable datasheets and manuals for current and discontinued terminal products such as their AM-65 text terminal, AM-75 colour terminal and AM-80 thin client.
I own an AM-62 text terminal from the 1980s.