On 2025-01-31 15:18, Wayne S via cctalk wrote:
Steve, remember that digital electronics ( I.E. integrated circuits like uarts)
weren’t around during the early days of data transmission. It was all analog
back then, coils, capacitors, and resistors, so then ideas regarding fast
transmission had to wait for the technology to evolve. Then as ic’s became
available, what you could do with them sparked new ideas. Example: data
compression within the modem using a microprocessor, thus getting higher
overall throughput than the theoretical maximum of just the modulation rate.
Sent from my iPhone
Or maybe electro-mechanical some early machines used a brush turned by a
synchronous motor over a circular commutator that had segments for each
bit. On transmit when you pressed a key you closed switches connected
to the data bit segments and the motor rotated the brush around once to
transmit the character. When receiving the incoming start bit would
start the motor and as the brush went around it would pick solenoids to
select the correct character and the stop bits(s) would trip the cycle
clutch to print the character.
Paul.
