Creating a UEF from an unusual source

discuss PC<>Acorn file transfer issues & the use of FDC, XFER, Omniflop/disk etc.
aloishis89
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Creating a UEF from an unusual source

Postby aloishis89 » Tue Jul 19, 2016 8:50 pm

This is my first post and I'm brand new to the Acorn community. The reason I'm posting is that I came across a recording of a BBC TV show where they played the audio of a program for the BBC Micro and instructed viewers to connect their TV to a cassette recorder, record the audio, and then rewind and play it back to run the software. I'd like to try to recover this program, but I wanted to see what you all think, since I've been unsuccessful so far. The original video was probably ripped from a VHS tape and transcoded into what I think is H.264. I stripped the audio track from that video and exported it to a raw, headerless 8 bit unsigned file with a 44100 sample rate with Audacity. I've tried various options in MakeUEF (like phase shifting and trying different settings), but haven't gotten BeebEm to read anything. I've been unable to create a CSW because I can't run CSW.exe on my computer (Windows 10, 64 bit). If you want to take a look at the audio I'm playing with, a 16 bit PCM WAV is here: http://hscott.net/full_take.wav. I'd really appreciate any ideas or thoughts on this. Thanks!

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jms2
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Re: Creating a UEF from an unusual source

Postby jms2 » Tue Jul 19, 2016 9:41 pm

Hello and welcome to the forum! :D

I have never dabbled with UEFs but I like the challenge that you've given yourself! My suggestion (which is an entirely naive one) is that maybe you should adjust the frequency of your recording so that the steady tone is 2400Hz. This is what the BBC uses to recognise a tape recording.

Commie_User
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Re: Creating a UEF from an unusual source

Postby Commie_User » Tue Jul 19, 2016 9:50 pm

There are other factors as well, such as EQ settings. And that's after you've copied the recording in as high a standard as possible, uncompressed, to the hard drive for testing on a real BBC first.
Last edited by Commie_User on Tue Jul 19, 2016 9:52 pm, edited 1 time in total.

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MartinB
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Re: Creating a UEF from an unusual source

Postby MartinB » Tue Jul 19, 2016 9:51 pm

It's obviously nearly there because on a very quick check, pushing it directly into a real computer (a Master as it happens) and doing an un-scientific fiddle of the volume and equalisation on the PC, I can see that there's a short program, 4 and a bit blocks long, called THAMES but there's sufficient Data? etc. errors to stop it loading properly. I suspect with more accurate adjustment, maybe plus a scope, the program could perhaps be recovered.
Last edited by MartinB on Tue Jul 19, 2016 10:10 pm, edited 1 time in total.

Commie_User
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Re: Creating a UEF from an unusual source

Postby Commie_User » Tue Jul 19, 2016 10:09 pm

Sod this, my ears are bloody bleeding! And at the lowest volume too!

It's been done elsewhere anyway: https://m.reddit.com/r/ReverseEngineeri ... f=readnext

Commie_User
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Re: Creating a UEF from an unusual source

Postby Commie_User » Tue Jul 19, 2016 10:17 pm

It's not worth the effort. And for the tags, the show was DATABASE on THAMES TELEVISION, broadcasting a BBC MICRO PROGRAM competition.
Attachments
THAMES.mp3
(568.13 KiB) Downloaded 24 times

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BigEd
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Re: Creating a UEF from an unusual source

Postby BigEd » Wed Jul 20, 2016 4:48 pm

If it often turns out that there are some marginal tape recordings which don't respond well to the usual tactics, maybe a bigger hammer is needed. So, let me leave this here:
http://dsp.stackexchange.com/questions/ ... n-software
(How to demodulate an AFSK signal in software)
which looks like it contains some useful ideas. Essentially, we only want to try to pick out the two tones, and we know what they are - or, we know what they were when originally recorded. The nice thing for us is that we don't need high performance or efficiency.

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CMcDougall
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Re: Creating a UEF from an unusual source

Postby CMcDougall » Wed Jul 20, 2016 5:39 pm

viewtopic.php?f=6&t=5987#p56019
bible lessons above ^

Easy answer is don't use Audacity it's utter pants.
Useless even for vinyl rips , never mind just 300-3600 hz :lol:
No peaks or troughs [-(

EDIT: here is another, using old videos:
viewtopic.php?f=11&t=1554&p=80683&hilit=used+youtube#p80683
ImageImageImage

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CMcDougall
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Re: Creating a UEF from an unusual source

Postby CMcDougall » Sat Jul 23, 2016 11:23 am

Noticed in the video link above, he has same phone as me from month1 year1975 :shock:
:lol:
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13717291_10153979500937730_4037995534403212567_o.jpeg
ImageImageImage

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hoglet
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Re: Creating a UEF from an unusual source

Postby hoglet » Sat Jul 23, 2016 11:52 am

CMcDougall wrote:Noticed in the video link above, he has same phone as me from month1 year1975 :shock:
:lol:

My Dad was from Jedburgh!

We used to go there two or three times a year in the 1970s.

Dave

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CMcDougall
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Re: Creating a UEF from an unusual source

Postby CMcDougall » Sat Jul 23, 2016 12:18 pm

:D any pics you need from Jed, give me a shout!

Still to fix a white phone from Month3 year1967 my dad had when I was a kid recording me on reel to reel tape!
THAMEScomp.png

did anyone get the answer :?:
ImageImageImage


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