25 Jun
2021
25 Jun
'21
4:54 p.m.
On Fri, Jun 25, 2021 at 3:53 PM Grant Taylor via cctalk
<cctalk at classiccmp.org> wrote:
From my naive point of view, I wonder if it would be possible to build
some sort of USB device that has a traditional UART that has supporting
circuitry to connect to the host over USB. -- I say this because it
sounds like many ~> most ~> all (?) USB to RS-232 converters are doing
something inferior.
Of course that has been done in commercial products. For example I
have some Inside Out Networks Edgeport / 4 devices (apparently later
sold by Digi) that are implemented using a traditional ST16C654 quad
UART and MAX3243E RS-232 transceivers, with an Intel 80930
microcontroller as the interface between the UART and the USB host.
The Intel 80930 has an 80251 core integrated with a USB interface, and
was one of the first microcontrollers available on the market. This
device dates from 1997, so reasonably early in the USB game.