Re: Amiga serial port programming question

From: Marko Mäkelä (
Date: 2004-01-25 15:51:03

On Sat, Jan 24, 2004 at 04:06:56PM +0100, Daniel Kahlin wrote:
> Oh, sorry I missed that it was writing you asked for.  Over5 doesn't use 
> normal RTS/CTS or Xon/Xoff handshaking, so write doesn't really need 
> timeouts.

I see.  I'm using Xon/Xoff handshaking when sending to the C2N232 adapter,
and no handshaking when receiving.

> Do you really need to know the exact offset of the timeout though?

Well, it would only be a status display for the user.  I've disabled it
now in the Amiga version.  I also rewrote the initialization and cleanup
routines, to see if the crashes go away.  I had allocated the IOExtSer
struct statically, and not with CreatePort and CreateExtIO as it probably
should be done.

> It would be a big improvement over single byte writes if you could just 
> send a block, and then maybe resend that block if there were errors.

That is not an option when emulating tape via a microcontroller that has
only 128 bytes of RAM.  I have never had problems with lost bytes or errors.
Hmm, it would be interesting to drive the C2N232 via a pair of fast modems,
but I guess that modems faster than 2400 bps would introduce all sorts of
handshaking and buffering problems. :-)


PS: My KIM-1 Hypertape encoder works now.  Any KIM-1 users who are interested
in recording a test WAV file on audio tape and loading it on the KIM-1?

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