[Coco] Reading data through the bitbanger port

[dave at davebiz.com]

As Tim mentions in his reply, the serial port really needs a tight 
assembly language routine in order to read it in a practical way. Most 
UARTs (hardware serial ports) use a 16x clock to read data accurately. 
Therefore, a 19,200 bps serial stream would require a 307.2 kHz clock.  
So a CPU clocked at 890 kHz and requiring multiple clocks per 
instruction just doesn't hack it in BASIC. However, if you are only in 
need of a very slow data rate, maybe less than 300 bps, you *could* 
feasibly write a BASIC program which could read data in through the 
serial port.


Dave


On 3/29/2021 12:03 PM, Salvador Garcia via Coco wrote:
> Hi all, I am interested in knowing how the CoCo serial port works. I understand that it doesn't support reading data from it out of the box since it was intended more as a printer port.
> Does anyone know how I could read data from it? Thanks Salvador
> PS: I have not been able to resolve the problem receiving post from the list, but I can see your replies using the maltedmedia archives. I can also work around this to reply.
>