Re: serial port under CP/M

[alex.freed.007@gmail.com]

On Jan 15, 4:32 am, Steven Hirsch <snhir...@gmail.com> wrote:
>
> There were definite speed limitations when using the host computer's serial
> interface, so don't expect it work fast than 9600 baud.

Well, I don't think the (affordable) modems at the time were very
fast. I probably
bought anything faster than 2400 baud no earlier than 1989.
Clearly having to go through the z80<->6502 channel for every
character sent
or received was not very fast.


> That was the problem
> that Ray Klein's SIO piggyback was intended to address.  It plugged onto the
> same headers as the banked memory expansion cards and provided a Z80 SIO and
> DB-25 connector.

Well, the USB UART should address the same problem now :)

P.S. the boards are submitted for production, but due to some big
holiday in China
I don't expect them made  till the end of January.


-Alex.