[fpc-pascal] x86.pp and oldlinux.pp

[Holger Bruns]

Gustavo Enrique Jimenez schrieb:
>
> Accessing serial ports in linux could be as simple as to write/read
> to/from /dev/ttySx . You don't need io ports. For a multiplatform
> solution, use synapsis/synaser.
>   
Sometimes it is useful to get more information about device drivers. 
Searching the internet for that information is pretty difficult, because 
there is no detailed description available, as far as I see. The first 
hit on google points to a website for "device detectives". If I intend 
to use device drivers, I need to know how to access the ports of a 
device, which means in my case to a serial port based on the 16550D 
Universal Asynchronous Receiver/Transmiter with FIFOs. I need to read 
and write every register of that UART as explained in the National 
Semiconductor databook, register by register, address by address. No 
information on that topic seems to be available, but a whole bunch of 
useless idle talk and advertisement.

Hence I cannot use /dev/ttySx for accessing serial devices.

The only way to use serial ports successfully to me, is to use the unit 
serial on fpc, if I choose fpc to deal with serial ports. Another 
problem results from misleading comments on the implemented procedures 
and functions. As explained, seropen would return a zero, if a device 
cannot be found. For real, seropen returns a zero, if this device is 
found, and -1, if not.

Under the bottom line, it is embarrassing time consuming for a newbie 
like me, to work successfully with serial ports on linux.

> ps: Excuse my english. Helping you is very hard: you don't listen.
>   

On a mailing list, I can only read and write. ;-)

Best regards, Holger