Re: A89: Re: Serial Communication in ASM


[Prev][Next][Index][Thread]

Re: A89: Re: Serial Communication in ASM




Thanks for taking the time to try and answer my question.

But, that is not the problem.  I wrote the particular PC program
that I am using.  It does not have anything to do with VT100 or any
other standard.  It simply displays whatever is received at the
COM port.  And it displays nothing.  Even if it were receiving
binary rather than ascii, it would show something.  But I get no
indication that anything is received at all.

In the example I used, I transmitted a pure 'string' so even if it 
were in a binary format, that format would have produced an ascii 
string.

I think the problem lies in the fact that there must be some 
handshake thing that I am not doing.  I did read something about
a low level control of the link port, but I assumed that the 
transmit() function just filled the transmit buffer and that was
blindly sent to the link port.  Apparently that is not so.



From:           	"Miles Raymond" <m_rayman@bigfoot.com>
To:             	<assembly-89@lists.ticalc.org>
Subject:        	A89: Re: Serial Communication in ASM
Date sent:      	Thu, 28 Jan 1999 17:46:12 -0600
Send reply to:  	assembly-89@lists.ticalc.org

> 
> I'm not exactly the one to answer all of your questions, but I think that
> the PC program only echos VT100 or other specific data over the serial port.
> For this you would have to know about the VT100 standard and how it sends
> and receives data.  I have no idea where to find this information other than
> that it is probably on the net somewhere.
> 
> I think what your code does is just send binary data through the link port,
> and since it is not VT100 standard, the PC doesn't display it.  If the PC
> program did display anything, it would be in binary and look something like:
> 0010100011101100101110011010001011100001101100101101011011010101011010101010
> 10101010101010100101
> since it is twelve characters long. (8bits per char)
> 
> I don't think baud rate has anything to do with this since this is a
> hardware thing and the GL has a constant baud of 9600, and the PC adapts to
> that.  Has anyone gotten the GL to do anything lower?  I've tried to connect
> my GL to a very very old modem and it wouldn't work.
> 
> No handshaking is necessary in your example, since all the PC is doing is
> echoing (displaying) what is sent over the serial port you specified.
> 
> Of course, I may be wrong about all of this and it might be something as
> simple as you accidentally set the program to listen to the wrong COM port
> =)
> 
> -Miles Raymond      EML: m_rayman@bigfoot.com
> ICQ: 13217756       IRC: Killer2        AIM: MRayMan
> http://www.bigfoot.com/~m_rayman/
> 
> -----Original Message-----
> From: ipscone@halcyon.com <ipscone@halcyon.com>
> To: assembly-89@lists.ticalc.org <assembly-89@lists.ticalc.org>
> Date: Thursday, January 28, 1999 11:55 AM
> Subject: A89: Serial Communication in ASM
> 
> 
> >What is required to send data over the serial port, using ASM?
> >
> >There are several serial I/O commands but I'm not sure what
> >is required.
> >
> >How would one modify the Hello World program to, in addition
> >to sending 'Hello World' to the screen, it would also send
> >it out over the serial port.
> >
> >I have a program that echos to the PC screen anything received
> >by the COM port,
> >
> >I added the following to the Hello World program, just between
> >correcting the stack and the idle statements, but nothing was
> >displayed on my PC screen.  So, obviously there is something
> >that I am missing.
> >
> >   move.w  #12,-(a7)  ; 12 words to xmit
> >   pea  hello(pc)  ; pushes address of string to stack
> >   jsr  doorsos::transmit  ; transmits data
> >   lea  6(a7),a7           ; corrects stack
> >   jsr  doorsos::flush_link
> >
> >What else is required?  What is baud rate?  Is there any
> >special handshake required, on the PC end?  What?  Is there any
> >source code example, for this handshake, if requried?  Where?
> 
> 


--
-----------------------------------------------------------------
Discussion Group:        http://www.halcyon.com/ipscone/wwwboard/

Protect your constitutional rights. Your favorite one may be next!
-----------------------------------------------------------------


Follow-Ups: References: