I have an Acorn Electron that came without tape recorder, so I'm using Audacity to record and replay programs which works fine. Now I also have some software as UEF (Universal Emulator Format) files. These can be converted to .WAV using the 'FreeUEF' software for Windows.
The problem is that so far I only managed to load one program to my Electron this way. All others start out showing the name of the program and the first block number (00) but then immediatly show:


As the .WAV file is still playing it soon finds the next block and continues loading. But when the loading is finished it looks like the computer does not detect the end and the program does not start.
I've tried several differnt settings for the output volume, but that does not solve it. Also, when I record my own (Basic) programs and replay them it always works fine.
My guess is that the converted .WAV file does not not contain a proper header or starting tone so the computer misses the first byte(s) but I could be wrong...

  • I'd never heard of UEF, but a quick search shows it doesn't just put the data in the container, but tries to reproduce the media signals. Which is pretty cool, and also suggests that the source program signals weren't in the best shape when converted into this container format. There are utilities for "cleaning up" UEF files, which I suspect get rid of noise and compress things a little so the signals are easier to sample. Pretty cool question. (I suppose the resample to WAV could also have caused the problem, as any format change could introduce artefacts.)
    – user12
    Commented Apr 26, 2016 at 14:43
  • Can you provide a link to a failing UEF?
    – Tommy
    Commented Jul 22, 2017 at 15:19

2 Answers 2


You might want to check this site out. It appears there are a bunch of utilities that help "clean" the sound, the fact that these exist probably mean that these UEF files are especially sensitive to signal/noise issues. http://www.retroisle.com/others/acornelectron/software.php

  • 2
    Link-only answers are not that great for SE sites. Can you provide an overview of what utilities and techniques are typically used in this situation?
    – user12
    Commented Jun 8, 2016 at 21:30
  • Can you expand on this answer using information from the link? This doesn't really explain why one format works and the other doesn't, and would probably have been better off as a comment as is.
    – Matt Lacey
    Commented Jun 9, 2016 at 2:27

Get uefwalk from here or elsewhere. Then run:

./uefwalk --output=bitstream in.uef |
./kleen/bitclean -i -|
aplay -f cd -c 1

Replace aplay with

sox -t raw -c 1 -L -b 16 -e signed -r 44100 - -t wav out.wav

if you want to save the output rather than play it.

In my experience this has proved perfectly reliable at getting data into a BBC Micro. I imagine Electrons are similar, though I don't have one to test on.

Note that many UEF files are gzipped, so you may need to rename them to have a .gz suffix then gunzip them before uefwalk will read them.

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