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Re: [RTTY] EXTFSK64 Re: [MMTTY] 75 baud RTTY with EXTFSK ...

To: "7L4IOU" <ncb02761@nifty.com>, "RTTY" <rtty@contesting.com>
Subject: Re: [RTTY] EXTFSK64 Re: [MMTTY] 75 baud RTTY with EXTFSK ...
From: "Gary AL9A" <al9a@mtaonline.net>
Date: Sun, 21 Sep 2014 20:27:26 -0800
List-post: <rtty@contesting.com">mailto:rtty@contesting.com>
Yes it did Hisami-san!  Thank you for both of my JA QSOs at 75 baud.

73,
Gary AL9A

-----Original Message----- From: 7L4IOU
Sent: September 21, 2014 7:07 PM
To: RTTY
Subject: [RTTY] EXTFSK64 Re: [MMTTY] 75 baud RTTY with EXTFSK ...

Hello Friends,

This post is raked up 3 years old thread. hi

There were two problems in conventional EXTFSK.
One, can not keying 75 baudot FSK.
Two, does not work for LPT port of 64 bit Windows.

I found New EXTFSK64 in the JA7UDE's Web page.

<http://www.qsl.net/ja7ude/extfsk/>

and it's a beta version,
but worked very well with N1MM+ this morning.

Oba-san, Thank you very much!

73, Hisami 7L4IOU


--- Original Message ---
From:     Robert Chudek - K0RC <k0rc@citlink.net>
To:       "Joe Subich, W4TV" <lists@subich.com>
Subject:  Re: [RTTY] [MMTTY] 75 baud RTTY with EXTFSK ...
Date:     Wed, 21 Sep 2011 00:29:53 -0500

/"Have you tried running FSK on the *serial* port?"/

Well there you go! I couldn't see the forest for all the trees in the
way! I had COM1 = CAT stuck in my brain and had not given it any other
consideration! But wait... there's even more... I think I'm on a roll...

my docking station has three slots for PCI cards... that gives me
another option. I guess I've broken through my brickwall and have
plenty
of experiments I can run. Thanks again for the insight.

73 de Bob - KØRC in MN
----------------------------------------------------------------------
--

On 9/20/2011 11:12 PM, Joe Subich, W4TV wrote:

Bob,

And of course, as you pointed out, there are a variety of other
methods to operate at 75 baud. My contesting computer is an older
Dell laptop C640 with a docking station. It provides one serial and
one parallel port. The serial port runs the CAT and FSK / PTT run
from the LPT port.

Have you tried running FSK on the *serial* port?  If it is a real
serial port (and it may be if you have a true docking station
instead
of a multifunction USB adapter), it should run both 45.45 and 75
baud with MMTTY or MMVARI using the standard drivers (serial port
for MMTTY and FSK8250 for MMVARI).   It would be very easy to add
a generic USB converter for CAT/CW/PTT.

These manufacturers discuss thr top speed but there is no mention
of
the lowest speed supported. The second link refers to the MCS9835
LSI
device which supports 5, 6, 7, and 8 bits, which sounds promising.

The MCS9835 is a MOSCHIP device that is capable of providing two
16C550 compatible serial ports and one parallel port depending on
the external components.  A 16C550 compatible serial port should be
capable of 45.45 baud operation and while the data sheet:
     http://www.comet.bg/datasheet/Interface/9835.pdf
does not specifically list a baud rate divisor for 45.45 baud, the
1.8432 MHz baud rate clock is low enough and the baud rate table
shows a divisor of 1 for 115.2 K that 45.45 would surely be
available
with a baud rate divisor of 09E6(h) or 09E7(h) (45.46 or 45.44 baud).
Assuming the divisor is a 12 bit number as in the 8250/16450 UART
and
FTDI USB UART, the lowest (standard) data rate would be 30 baud.

> What is your opinion of finding a PCMCIA adapter that might be
> "slow
> enough" to direct key FSK from MMTTY?

There are plenty out there ... two port PCMCIA adapters were a
common
solution for laptops before USB became so ubiquitous.

73,

   ... Joe, W4TV



On 9/20/2011 10:57 PM, Robert Chudek - K0RC wrote:
Hello Joe,

Thanks for the detailed technical background regarding the
limitation of
the implementation of the EXTFSK driver. It's no secret I have been
vocal about the possibility of extending the capability to 75 baud.
Unfortunately I don't have the programming background or skill to
meddle
with the source code.

And of course, as you pointed out, there are a variety of other
methods
to operate at 75 baud. My contesting computer is an older Dell
laptop
C640 with a docking station. It provides one serial and one
parallel
port. The serial port runs the CAT and FSK / PTT run from the LPT
port.
This has worked fine for years. (Yes, I am waiting for Ed McMahon
to
show up with the check, then I'll upgrade!)

This discussion made a light bulb come on... the laptop has a pair
of
PCMCIA ports. I see a variety of PCMCIA adapters that provide
serial
ports. Here's a couple examples:

*http://tinyurl.com/6ed3869*

*http://tinyurl.com/2z2c2w*

These manufacturers discuss thr top speed but there is no mention
of the
lowest speed supported. The second link refers to the MCS9835 LSI
device
which supports 5, 6, 7, and 8 bits, which sounds promising.

What is your opinion of finding a PCMCIA adapter that might be
"slow
enough" to direct key FSK from MMTTY?

73 de Bob - KØRC in MN
-------------------------------------------------------------------
-----

On 9/20/2011 8:35 PM, Joe Subich, W4TV wrote:


 From time to time I see comments that some individuals would like
to
see JE3HHT modify EXTFSK to support 75 baud RTTY. I have recently
exchanged e-mail with Oba, JA7UDE about that possibility and Oba
advises that he attempted to add 75 baud support to EXTFSK some
years
ago without success due to problems with bit period instability
(jitter).

EXTFSK uses the Windows Multimedia Timer that has a maximum
resolution
of 1 millisecond. However, the timer is not stable due to the
nature
of Windows process swapping, etc. I have measurements (scope
photos)
made by OM7ZZ at microHAM which show the 22 millisecond bit period
from EXTFSK will vary +/- 2 ms (+/- 10%) on either a motherboard
UART
or USB converter (measurements made on both devices to eliminate
the
effects of USB latency). The instability (jitter) is due to the MM
timer and thread switching in the Windows operating system.

If we apply a 1 millisecond resolution and 2 millisecond jitter to
75
baud, we start out at 77 baud (13 ms bit period). With 2ms jitter,
the baud rate can vary from as low as 66.6 (15 ms bit duration) to
as
high as 91 (11 ms bit duration). A +/-15% instability in baud rate
will result in significant performance issues.

There are other solutions for 75 baud FSK operation with MMTTY. If
you
have a serial port (motherboard or add-in card) MMTTY will support
it
directly. If you have only USB ports, some of the better
interfaces
(all of the microHAM "Keyers", RigExpert Standard and Plus,
Navigator
by US Interface) support 45 and 75 baud operation using a UART
(serial
port) compatible interface, or you could use an AFSK to FSK
converter
like the FSKit by K4DSP in the August 2011 QST (pp 40-42).

Finally, one can always use AFSK.

By the way, JE3HHT has released the source code of EXTFSK to the
public
domain. Anyone is free to add 75 baud support if they wish. There
are
additional timers with better resolution in Windows 2000 and later.
It
would not be at all inconceivable for a dedicated programmer who
was
willing to do the research and work to use the same basic approach
with
a different timer to add 75 and 110 baud support to EXTFSK if they
wanted to do so. The source code is part of EXTFSK106.zip
available
from www.hamsoft.ca ... have at it boys!.

73,

... Joe, W4TV

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