Solved

high baudrate serial port use without serialDMA

Posted on 1998-06-26
4
225 Views
Last Modified: 2013-12-26
I am using a PowerBook5300C and need to read a few K data
from a device sending it over a serial line at 230k4 baud.

The PB5300 does not have the serialDMA driver, so using the
serial driver will only provide speeds up to 57k6 (the
extra csCodes for the 2 high baudrates do not work)

I know that LocalTalk operates at high speeds and does not
use the serial-driver.

Can anybody give me any reference/source/help/info on
how to implement this: reading a few K data at 230k4
without using the serial driver? (the cpu does not have
to do anything else during reading the data)

Thanks
Frank
0
Comment
Question by:frb
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
4 Comments
 

Author Comment

by:frb
ID: 1291464
Edited text of question
0
 

Author Comment

by:frb
ID: 1291465
Edited text of question
0
 
LVL 1

Accepted Solution

by:
agolan earned 150 total points
ID: 1291466
Localtalk uses SDLC framing to achieve the 230.4Bps.
SDLC = Synchronous Data Link Control.

Unlike what is known as "serial" or "rs232" communications,
that is actually asychronous communication, the SDLC is Synchronous, and it means that it need a synchronisation signal,
Apple induce this signal using something they called FM-0, also called "biphase space".
Note also that Appletalk needs RS-422 signalling, that unlike RS-232 is balanced, that is: there is a pair of wires for the data in each direction.
I know that they were "phonenet" attachment cables that used only a single pair of wires, but they converted the RS-422 data into some kind of modulation.

So the bottom line is that there is no good solution for you.

If you could tell a bit more about what you are trying to achieve, I might be able to help.

I had progarmmed telecommunications stuff for the Mac for several years (several years ago ;-) )
0
 

Author Comment

by:frb
ID: 1291467
i found out that it is possible to use asynchronous communication
at 230k4. also somebody send me an example of how the SSC can be
accessed directly.
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Here is how to use MFC's automatic Radio Button handling in your dialog boxes and forms.  Beginner programmers usually start with a OnClick handler for each radio button and that's just not the right way to go.  MFC has a very cool system for handli…
Introduction: Dynamic window placements and drawing on a form, simple usage of windows registry as a storage place for information. Continuing from the first article about sudoku.  There we have designed the application and put a lot of user int…
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
If you're a developer or IT admin, you’re probably tasked with managing multiple websites, servers, applications, and levels of security on a daily basis. While this can be extremely time consuming, it can also be frustrating when systems aren't wor…

724 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question