You gotta just love historical records departments they take
you back so far in time. I don't throw anything away and it shows
sometimes. I took a look yep there it was a box of paper tape
backups sealed in 1970 and following me around. The scotch
tape now almost dust opened it up and staring at me top of
the box a tape that said Morse 11-Nov-1974 right behind
it another tape with the sources.

Bunch of old projects, things don't change.

Out of another box was a hand pulled tape reader 9
(8 +sprocket)   mounted photo sensors that someone
sold as a kit at an early personal computer show. Just
add a pull mechanism and light a parallel port and
some software. Time to call Gord an old friend with
a passion for old computer equipment, bet he has a
working teletype. When I get this read I'll post this
relic from the past.

w..




Walter Banks wrote:

> I wrote a Morse decode for demonstration for a friend for a ham
> convention in the early 70's on a PDP8/e. It was designed to be
> speed tracking and worked quite well on hand sent code. The
> algorithm I used was to base the starting speed on the the last
> received character and analyse the speed of the received
> character to update the received speed. I remember two
> things debugging the code. For a while small noise pulses
> were interpreted as dots and were hard (at the time) to filter
> out in software. the second thing that should not have been
> a surprise was the dit / dah ratio in hand sent code was far
> from close and we did some tracking on the ratio as well.
>
> It was a weekend project I wrote the code and Roger Grant
> created a interface to a receiver. It was a hit around the ham
> convention. One of the attendees was an old railway telegraph
> operator whose code on a straight key might as well have been
> machine generated. The console on this old computer was
> a teletype and his code might as well have been typed from
> a file.
>
> The code is somewhere in the historical records department
> at Byte Craft then all I need is to find a paper reader that
> has been run in the last 20 years.
>
> w..
>
> David VanHorn wrote:
>
> > > The sounder already works but the code is un-clean. I'm still well under 200
> > > words. I think that I can fit a complete sender and receiver in the smallest
> > > available pics (12{c,f}508} with an external eeprom for some fun projects.
> >
> > I'm interested to see how you implement the decoder part, particularly
> > with off-air signals.  I know the boxcar integrator approach for tone
> > filtering, I've used it in several DF projects, but hadn't thought
> > that you could implement it in a more wideband version.
> > --
> > http://www.piclist.com PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist


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