[Coco] Re: History of Tandy/Radio Shack Cassette Recorders

[Theodore Evans (Alex)]

On Dec 17, 2003, at 4:45 AM, Torsten Dittel wrote:
>
> The FSK mode was introduced for use with mechanical teleprinters in the
> mid-1900s. The standard speed of those machines was 45 baud, equivalent
> to about 45 bits per second. When personal computers became common and
> networks came into being, this signaling speed was tedious. 
> Transmission
> of large text documents and programs took hours; image transfer was
> unknown. During the 1970s, engineers began to develop modems that ran 
> at
> faster speeds, and the quest for ever-greater bandwidth has continued
> ever since. Today, a standard telephone modem operates at thousands of
> bits per second. Cable and wireless modems work at more than 1,000,000
> bps (one megabit per second or 1 Mbps), and optical fiber modems
> function at many Mbps. But the basic principle of FSK has not changed 
> in
> more than half a century. <<

Current modems use PSK (Phase shift keying) and actually encode 
multiple bits on a single period.