Handshaking With Serial Ports In Mac QuickBASIC 
Author Message
 Handshaking With Serial Ports In Mac QuickBASIC


> I have noticed that adding the "RS,CS,CD,DS" helps to avoid timeout
> problems with some serial ports in direct-connect situations, or with
> some older external modems, but it appears to prevent high-speed
> error-correcting modems from working.

I am using a regular 14400 external modem which supports compression,
hardware handskaing, and all that.  Currently, I have the following
command in a BASIC terminal program I'm working on:

OPEN "COM1:57600,N, 8, 1" AS #1 LEN=4000

You mention that "RS,CS,CD,DS" does not work well with high-speed modems.
So what would be a better combination of letters to append to the above
command for the best performance on my 14400?  The terminal program will
only use one serial port and will only be used to call other numbers (it
won't even support ANSI).

> RS and CS without arguments disable RTS/CTS

You say the RS and CS commands disable hardware handshaking (RTS/CTS).  So
does that mean it ENABLES software handshaking (Xon/Xoff)?  If not, what
commands can I use to enable Xon/Xoff?  Or if it's possible, what commands
can I use to enable hardware handshaking?

> ME (thank you Bob!) masks out framing and overrun errors, a very common
> occurance especially where modems are involved.  These errors usually
> occur at the worst possible time and tend to blow apart even the most
> logically designed program.  ME causes powerbasic to simply ignore these
> nit-picky little UART snits.

Would you recommend using ME in my case (14400)?

> FE is an option which flushes the byte currently in the UART holding
> register when an error occurs (ever see ? ? suddenly appear when line #2
> rings, when a jet flies overhead, or when the A/C cuts on? FE fixes
> that!).

How about this one?  Does it slow anything down?

One other question... any idea how I can open a serial port at 38400?  I
can only get 19200 or 57600 to work for high-speed modems...

Thanks for any help anyone can offer!

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Thu, 04 Dec 1997 03:00:00 GMT  
 [ 1 post ] 

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