"Digital Prawn" wrote:

> SSTV - looks like it is trying to load another file called SSTV? or
> something, so it never starts.

Both of the tapes end with a headerless data block, which is rather
unusual unless it's something like a turbo-loader. Could be a bad dump I
suppose.

I think the "SSTV?" file is a red herring: that's called "SSTV SCREEN$"
(though the token probably won't show up correctly in an emulator's tape
browser); it's just the loading screen.

Eq.

Paul E Collins wrote:
> Both of the tapes end with a headerless data block, which is rather
> unusual unless it's something like a turbo-loader. Could be a bad dump I
> suppose.

Thanks for looking at it.

You are indeed correct about the "SSTV SCREEN$" filename. I was looking
at what the IX register was pointing to whilst the PC was inside the ROM
load routine to try to ascertain what filename it was trying to read in.

I didn't have the token table to hand at the time, but indeed the
character in question is decimal 170, which is SCREEN$.

So, it's just trying to load the loading screen in again.

The loader itself does use the ROM routines, however since it calls them
via m/c I think it can still theoretically load in a headerless block.

But yes, I thought this was unusual too.

I agree with your suggestion that this could possibly be a bad dump of
the tape.

It's just good to get someone else to have a look at it just to be sure
I'm not missing anything obvious,

Cheers, DP

Digital Prawn wrote in comp.sys.sinclair:

> So, it's just trying to load the loading screen in again.

IIRC what you do at that point is load in a screen dump (made in Melbourne
Draw or whatever) that you want to send over the air via SSTV. Typically
a Spectrum version of a QSO card, eg callsign in big letter, simple map of
where you are in the world or whatever.

HTH

- MDW.

Reply to myself but anyway page 70 of the following PDF link shows Speccy
SSTV and interfaces and example screens etc

http://sstv.ccone.at/downloads/sstv.pdf

HTH

- MDW.

Digital Prawn wrote in comp.sys.sinclair:
>
> So, it's just trying to load the loading screen in again.
>
> The loader itself does use the ROM routines, however since it calls
> them via m/c I think it can still theoretically load in a headerless
> block.

Me yet again. It could of course be waiting to receive the SSTV image
rather than something off the tape. This program worked by interfacing the
ear/mic socket to the transceiver, maybe it used the ROM routines to grab
data off the ear input and display it on screen as it is received.

Receiving SSTV is like loading screens but slower really innit ;-)

Thanks for bringing back memories of being upstairs with Dad faffing about
trying to receive images from the airwaves.

Hmm, SSTV simulator, maybe the seedings of a CSSCG entry there?

- MDW.

Matt Wilson wrote:
>
> Me yet again. It could of course be waiting to receive the SSTV image
> rather than something off the tape. This program worked by interfacing the
> ear/mic socket to the transceiver, maybe it used the ROM routines to grab
> data off the ear input and display it on screen as it is received.
>

Hi Matt,

Thanks for the replies.

I have now downloaded and read the PDF you linked to. It is a very
comprehensive source of information on SSTV, which is something I knew
nothing about until I attempted this screen grab.

The idea in your first post sounds good. So, I made a test tape with a
SCREEN$ in it, but I can't yet get it to be accepted by the SSTV program.

Whilst doing this, I did at least learn that I made an incorrect
assumption yesterday. I was wrong when I mentioned that the filename
stored in the area pointed to by the IX register was the filename that
was trying to be read in. It now seems that it simply contains the last
filename found on the current tape. Which is simply why it was set to
the name of the SSTV loading screen when I checked it.

So I now speculate that the SSTV program is trying to load any SCREEN$
file off a tape, perhaps the filename is unimportant.

Here's my test tape:-
http://java.cms.livjm.ac.uk/homepage...r/SSTVtest.tzx

There's probably something about the SCREEN$ file in the above tapefile
that the SSTV program doesn't like, but I haven't yet found what it is.

Regards, DP

Matt Wilson wrote:
>
> Me yet again. It could of course be waiting to receive the SSTV image
> rather than something off the tape. This program worked by interfacing the
> ear/mic socket to the transceiver, maybe it used the ROM routines to grab
> data off the ear input and display it on screen as it is received.
>
> Receiving SSTV is like loading screens but slower really innit ;-)
>

Yes perhaps that is what is happening here. Alas I don't have a suitable
source currently available for this. Perhaps I could locate some
recording from the Internet or something, and feed it into the SSTV program.

> Thanks for bringing back memories of being upstairs with Dad faffing about
> trying to receive images from the airwaves.
>

I'm just glad to get a reply from someone who has used SSTV on the
speccy before.

> Hmm, SSTV simulator, maybe the seedings of a CSSCG entry there?
>
> - MDW.

Sounds like a potentially interesting title!

Digital Prawn wrote:
>
> I have now downloaded and read the PDF you linked to.

Oops, that's not quite right, I really meant that I read a small part of it!

Digital Prawn wrote:
> Matt Wilson wrote:
>>
>> Me yet again. It could of course be waiting to receive the SSTV image
>> rather than something off the tape. This program worked by interfacing
>> the ear/mic socket to the transceiver, maybe it used the ROM routines
>> to grab data off the ear input and display it on screen as it is
>> received.
>>
> > Receiving SSTV is like loading screens but slower really innit ;-)
> >
>
> Yes perhaps that is what is happening here. Alas I don't have a suitable
> source currently available for this. Perhaps I could locate some
> recording from the Internet or something, and feed it into the SSTV
> program.
>

if you download mmsstv that can generate sstv signals. I imagine the
software receives 8 or 12 second black and white transmissions.
I have tried it in the past though, and have never got that software to
behave.

Guesser wrote:
>
> if you download mmsstv that can generate sstv signals. I imagine the
> software receives 8 or 12 second black and white transmissions.
> I have tried it in the past though, and have never got that software to
> behave.

Thanks for this suggestion, Guesser. I have now downloaded this software
and I will try it out sometime soon.

I'm willing to try anything to grab a screen for this particular
software, since I have been stuck on it for a long time.

Cheers, DP

Guesser wrote:
>
> if you download mmsstv that can generate sstv signals. I imagine the
> software receives 8 or 12 second black and white transmissions.
> I have tried it in the past though, and have never got that software to
> behave.

Well I tried it, but it didnt seem to respond. It was worth a go though!

I found that Spectaculator 5.3 is a good emulator for loading in
whatever sounds are currently playing under Windows. Just select "Load
from Audio Source", it's that simple.

So as a control test, I did this, and then loaded up a game in the SPIN
emulator at normal speed, with the loading sound turned on.

The game simultaneously loaded up in Spectaculator, (well it had a lag
time of about a second behind SPIN, no doubt due to a sound buffer), but
it still loaded up perfectly OK.

With that set up, I then loaded up a snapshot of SSTV into Spectaculator
in the normal manner.

I then fired up mmtssv and I got my test picture ready, with my fake
call sign printed on it.

I got the program to output the audio version of the picture. It sounded
very musical.

But, the SSTV program running in Spectaculator did not respond. Still it
was fun messing around with that mmsstv program.

I'm now thinking though that the Speccy SSTV program is just waiting to
load in a standard ZX Spectrum tape file header through the ear port.

You can tell this as follows:-

Just keep playing any speccy tapefile repeatedly whilst on the SSTV
loading screen. You will see the usual filename messages characteristic
of the standard ROM routine start to scroll down the screen after a
while. You can't read them, as they are in black INK on black PAPER. I
suppose ATTR_P could be poked, if there was a need to view these messages.

But, it is picking up on the standard Speccy file headers. It's just
that it is not finding the particular header it is looking for.

Cheers, DP

Digital Prawn wrote:
>
> I then fired up mmtssv and I got my test picture ready, with my fake
> call sign printed on it.
>
> I got the program to output the audio version of the picture. It sounded
> very musical.

hmm, saying it sounded quite musical makes me wonder, did you change the
picture mode and fiddle about? the default mode would be Martin or
Scottie, "modern" modes, if this software responds to any sort of
standard sstv mode it would almost certainly be a black and white mode,
the 8 or 12 second modes.

sorry if you did do this, I just never thought the bw modes had that
musical lilt to them at all, just sound like noise to me

Guesser wrote:
> hmm, saying it sounded quite musical makes me wonder, did you change the
> picture mode and fiddle about? the default mode would be Martin or
> Scottie, "modern" modes, if this software responds to any sort of
> standard sstv mode it would almost certainly be a black and white mode,
> the 8 or 12 second modes.
>
> sorry if you did do this, I just never thought the bw modes had that
> musical lilt to them at all, just sound like noise to me

I selected the B/W 8 second mode and a few of the others, but I now
realise that my description of the sound was not entirely accurate.

You are correct that those modes just sound like noise, whilst the
picture is actually being scanned that is.

It is apparent to me now that what I described as "musical" is in fact
some sort of prelude to transmitting the image. Like some sort of code
that is sent out before the image is scanned.

It's just a few notes, played in quick succession, and also plays again
after the image has been completely scanned.

I don't know much about amateur radio or SSTV, so I'm not sure what it
is but it sounds like a little tune to me.

Digital Prawn wrote:
> Guesser wrote:
>> hmm, saying it sounded quite musical makes me wonder, did you change
>> the picture mode and fiddle about? the default mode would be Martin or
>> Scottie, "modern" modes, if this software responds to any sort of
>> standard sstv mode it would almost certainly be a black and white
>> mode, the 8 or 12 second modes.
>>
>> sorry if you did do this, I just never thought the bw modes had that
>> musical lilt to them at all, just sound like noise to me
>
> I selected the B/W 8 second mode and a few of the others, but I now
> realise that my description of the sound was not entirely accurate.
>
> You are correct that those modes just sound like noise, whilst the
> picture is actually being scanned that is.
>
> It is apparent to me now that what I described as "musical" is in fact
> some sort of prelude to transmitting the image. Like some sort of code
> that is sent out before the image is scanned.
>
> It's just a few notes, played in quick succession, and also plays again
> after the image has been completely scanned.
>
> I don't know much about amateur radio or SSTV, so I'm not sure what it
> is but it sounds like a little tune to me.

yes I know what you mean, the 'vis' code that comes before the
tansmission goes diddleiddleiddleummmm.

I think the colour modes are a little musical, which I thought you
perhaps meant.
doodleydoodleydoodleydoodley etc

Guesser wrote:
>
> yes I know what you mean, the 'vis' code that comes before the
> tansmission goes diddleiddleiddleummmm.
>
> I think the colour modes are a little musical, which I thought you
> perhaps meant.
> doodleydoodleydoodleydoodley etc

Indeed, I can confirm that I meant diddleiddleiddleummmm and not
doodleydoodleydoodleydoodley.

On Mar 31, 7:35 pm, Digital Prawn wrote:
> Guesser wrote:
>
> > yes I know what you mean, the 'vis' code that comes before the
> > tansmission goes diddleiddleiddleummmm.
>
> > I think the colour modes are a little musical, which I thought you
> > perhaps meant.
> > doodleydoodleydoodleydoodley etc
>
> Indeed, I can confirm that I meant diddleiddleiddleummmm and not
> doodleydoodleydoodleydoodley.

Hi all,

I'm going to take a look at this too - though from the SSTV / Radio
end of things. My license has long lapsed (need to look into that...)
but I did hold a class b license as 2E1AEX. I always wanted to get
SSTV working and play with it, but things like college, then Uni' and
drink and women kinda happened and I forgot all about it!

Cheers,
Gav.

> Hi all,
>
> I'm going to take a look at this too - though from the SSTV / Radio
> end of things.

Thanks for taking the time to look at it!

Someone mentioned to me the other day that they didn't think I'd get it
working without the correct hardware attached.

I have never owned any amateur radio hardware myself.

It'd be great to see someone get this up and running (assuming the tape
dump in the WoS archive is OK). There remains some uncertainty over
whether or not that tape file is completely OK.

Cheers, DP

On Apr 7, 2:01 pm, Digital Prawn wrote:
> > Hi all,
>
> > I'm going to take a look at this too - though from the SSTV / Radio
> > end of things.
>
> Thanks for taking the time to look at it!
>
> Someone mentioned to me the other day that they didn't think I'd get it
> working without the correct hardware attached.
>
> I have never owned any amateur radio hardware myself.
>
> It'd be great to see someone get this up and running (assuming the tape
> dump in the WoS archive is OK). There remains some uncertainty over
> whether or not that tape file is completely OK.
>
> Cheers, DP

From what I can gather (and in part remember) the Spectrum was one of
the only (possibly the only) home computer that could decode SSTV
without any additional hardware. Whether this SSTV prog wanted extra
hardware I don't know though... Still, it's fun figuring stuff out.

The CW prog is likely a morse decoder or encoder. I'll look at that
another time.

Cheers,
Gav.

gcallard@callard.co.uk wrote:
> On Apr 7, 2:01 pm, Digital Prawn wrote:
>>> Hi all,
>>> I'm going to take a look at this too - though from the SSTV / Radio
>>> end of things.
>> Thanks for taking the time to look at it!
>>
>> Someone mentioned to me the other day that they didn't think I'd get it
>> working without the correct hardware attached.
>>
>> I have never owned any amateur radio hardware myself.
>>
>> It'd be great to see someone get this up and running (assuming the tape
>> dump in the WoS archive is OK). There remains some uncertainty over
>> whether or not that tape file is completely OK.
>>
>> Cheers, DP
>
> From what I can gather (and in part remember) the Spectrum was one of
> the only (possibly the only) home computer that could decode SSTV
> without any additional hardware. Whether this SSTV prog wanted extra
> hardware I don't know though... Still, it's fun figuring stuff out.
>
> The CW prog is likely a morse decoder or encoder. I'll look at that
> another time.
>
> Cheers,
> Gav.
This is a test - new server. Please ignore me.

On Mon, 7 Apr 2008 10:41:03 -0700 (PDT) da kidz on comp.sys.sinclair were rappin'
to MC :

> From what I can gather (and in part remember) the Spectrum was one of
> the only (possibly the only) home computer that could decode SSTV
> without any additional hardware.

That's correct. There was a SSTV program (which did some form of text
communication as well) on Micronet that worked perfectly well with a
radio plugged into the tape port on the Spectrum. Never got any
worthwhile out of it, but it did at least appear to work!

Can't remember what it was called, but it had some sort of
Multiface-style menu along the bottom of the screen.

Chris


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