The biggest problems today with USB-to-Serial adapters is for
generating FSK and CW (some having problems generating CW).
But I have heard some say they have great success running CW using them.
For RTTY, the problem is support of 5 bit code. Most USB-to-Serial
converters today use a chip by Cypress called EZ-USB as the UART.
Although the EZ-USB can support 5-bit code, it is not programmed to
do so by most (maybe all) makers of USB-to-Serial adapters. Not one
single USB-to-Serial adapter using the EZ-USB chipset has been tested
to work for FSK (5-bit generation) code.
Some USB adapters do use the 16550 UART for serial conversion.
The 16550 does fully support 5-bit code. However, again, the chipset
must be programmed to accept 5-bit code for FSK transmission via
these devices.
There is one converter that has been proven (not by me yet) to successfully
run 5-bit FSK transmission and that is the Belkin F5U103 model adapter.
I know it works because I worked Dick, KD6AZN, while he was operating
in Japan and he was using the F5U103 to generate FSK. Despite his success,
others have had trouble using this adapter for FSK. I guess I need to break
down and buy one and test it with WriteLog.
But as the thread suggests, we are going to have to rely on these devices
in the future. No one is going to support 5-bit code because no one uses it
except us hams. I think it was Chen, W7AY, that might have suggested that
we change FSK to 8-bit code. Not a bad idea for the future if we want these
devices to work for us.
I've accumulated some data about USB-to-Serial adapters on my personal
website and this information can be accessed from my RTTY page at
www.aa5au.com/rtty.
I plan on purchasing a Belkin F5U103 one of these days and testing it. I will
share the results when it happens.
73, Don AA5AU
----- Original Message -----
From: "Steve Baron - KB3MM" <SteveBaron@StarLinX.com>
To: <w5xd@writelog.com>; <writelog@contesting.com>
Sent: Saturday, August 31, 2002 7:55 PM
Subject: Re: [WriteLog] USB support yes LPT and Com support no
> Super position on LPT and the potential NT family security issue.
>
> ----- Original Message -----
> From: "W. Wright, W5XD" <w5xd@writelog.com>
> To: <writelog@contesting.com>
> Sent: Sunday, September 01, 2002 00:13
> Subject: RE: [WriteLog] USB support yes LPT and Com support no
>
>
> > > The other thing that is being repeated by MS is they want to move
> > > EVERYTHING to USB and get away from not only LPT support but also from
> > > Com ports. We need to plan on only having USB in most every hardware
> > > manufacturers PC's in the future and adapt our software to this.
> > >
> > > 73 Dave K4JRB
> > > _______________________________________________
> >
> > I would like to add that there is a subtle difference important to
> > contesters between the future of LPT ports and the future of COM ports
> > in Windows. You can buy USB to LPT port adapters and you can buy
> > USB to COM port adapters, and it is likely they will continue to be
> > available for the foreseeable future.
> >
> > The difference between these that is important to contesters is
> > that all the usual functions contesters expect through COM ports--
> > rig control and CW output--are close enough to the main stream use
> > of COM ports that the drivers supplied by the manufacturers of
> > the adapters work just fine for ham use. The same cannot be said
> > of LPT ports--antenna relay outputs, L/R radio selection, and
> > even the way CW is output on LPT ports by ham software
> > require driver functions that are just not close enough to the
> > main stream use of LPT ports (printers just don't look like
> > antenna relays!) for the manufacturer's driver to do any good
> > for us. And don't overlook the fact that if you wanted to solve
> > this problem of the missing drivers, that the problem is
> > plural--adding the desired functionality to the USB to LPT
> > adapter is a different software exercise for each and every
> > manufacturer. I speculate that it is possible for such drivers
> > to be written--the hardware design of the adapters probably does
> > not prevent ham use of LPT ports on USB, but device driver
> > writing is a very specialized skill, and it also requires
> > extremely detailed documentation of the behavior of the device.
> > Its just not a good bet that these prerequisites will be met
> > for LPT devices.
> >
> > It is true that the built-in LPT ports on most current machines
> > all behave to the old PC/AT standards from IBM of the 1980's and
> > there are some widely used methods for getting ham software to
> > work under current Windows operating systems for those LPT ports.
> > My decision to not participate in those methods is because they
> > have to defeat the security built into the operating system in
> > order to work. But XP has that security built into for a very
> > good reason--Microsoft is trying to make their products more
> > stable and reliable. If a user of WriteLog wants to make that
> > choice, WriteLog will notice the LPT ports are accessible and
> > use them like in the old Windows 95/98 days. But WriteLog simply
> > is not going to be shipped with such functionality built in.
> > I hate saying "no" to customers, but this is a point on which
> > I will choose to live with the flak and carry on.
> >
> > Wayne, W5XD
> >
> > _______________________________________________
> > WriteLog mailing list
> > WriteLog@contesting.com
> > http://lists.contesting.com/mailman/listinfo/writelog
> >
>
> _______________________________________________
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> WriteLog@contesting.com
> http://lists.contesting.com/mailman/listinfo/writelog
>
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