UART 5/6bits char format

On Tue, 1 Sep 2009 09:40:24 -0600, "Not Really Me"
<scott@validatedQWERTYsoftware.XYZZY.com> wrote:


>Look up radioteletype on Wikipedia and you will see that 5-bit is still in 
>use.

While some radio amateurs might still use RTTY with 170 Hz frequency
shift for historical reasons, most radio amateurs prefer PSK31 or
similar more spectrally efficient modes for real time keyboard to
keyboard communication.

Paul OH3LWR

ArarghMail908NOSPAM@NOT.AT.Arargh.com wrote:
> On Tue, 1 Sep 2009 09:40:24 -0600, "Not Really Me"
> <scott@validatedQWERTYsoftware.XYZZY.com> wrote:
>
>> HT-Lab wrote:
>>> Hi all,
>>>
>>> I just wrote a simple driver for a 16750 UART and wondered if there
>>> are still (embedded) systems that use the 5 and 6 bits character
>>> length format?
>>> A quick google search showed that 5 bits/1.5 stopbits were used for
>>> old mechanical teletypes, not sure what 6 bits are used for.
>>>
>>> I assume these formats are no longer used but I might be wrong,
>>>
>>> Thanks
>>> Hans
>>> www.ht-lab.com
>>
>> Putting on my "Dilbert dinosaur suit", I did an embedded 5 bit
>> interface in the mid 80's.  The task was to make a baudot (5-bit)
>> converter for an early HP inkjet printer that had ASCII (7/8-bit)
>> serial and parallel interfaces. Done with a TI TMS7000 processor.
> You could almost do that with a UART, a ROM, and a little glue logic?
>
Or an FPGA, or...   Certainly lot's of solutions.  At the time this was in a 
$500 printer that was "modified" and resold for about $7000.   The chosen 
path was speed of implementation, although I can't remember why we chose 
that processor.  Was not in the main stream of what we typically used.

Scott 

Paul Keinanen wrote:
> On Tue, 1 Sep 2009 09:40:24 -0600, "Not Really Me"
> <scott@validatedQWERTYsoftware.XYZZY.com> wrote:
>
>
>> Look up radioteletype on Wikipedia and you will see that 5-bit is
>> still in use.
>
> While some radio amateurs might still use RTTY with 170 Hz frequency
> shift for historical reasons, most radio amateurs prefer PSK31 or
> similar more spectrally efficient modes for real time keyboard to
> keyboard communication.
>
> Paul OH3LWR

Who said "amateurs"?