HOW TO convert Spectrum software to run on a Spectrum Emulator

This page describes how to convert Spectrum software stored on audio cassettes to a format that can run on a Spectrum Emulator. The technique described involves sampling the data signal from the cassette using a cassette player and a standard PC soundcard. The sound sample is then converted using special programs.

Hardware required

IBM PC Compatible,
Soundcard with Line-In recording connection,
Cassette Player.

A Mono Cassette player may provide better results but a hifi or a personal stereo should do just as well. If you have Dolby Stereo, T-Bass, Bass Boost or a graphic equalizer then you should switch them off while the sampler is recording. You may have to adjust the volume to get it just right.

Software required

MS-DOS or any Microsoft Windows Operating System,
A sound sample recording and editing program (I use CoolEdit 96 which was available free on a magazine cover disc),
voc2tzx. This is a utility to convert raw .voc files to .tzx format
- available from http://www.worldofspectrum.org/utilities.html#tzxtools,
Note: another utility called Taper is available but I have never had much success with it.

A Spectrum Emulator capable of loading TZX files and saving Z80 files
- I use x128v09b Spectrum Emulator by James McKay to convert the TZX files to nice Z80 files.

Method

1. Load your sound recording software on the PC,
2. Set the recording rate to 44107Hz, Mono, 8-Bit and start recording,
3. Play the tape containing the Spectrum program from the start to the end,
4. Stop the sound sampler on the PC,
5. Cut the recorded sound sample to start exactly at the beginning of the pilot tone and to end just after the last part of the data signal,
6. Save the sound sample in the SoundBlaster VOC format,
7. Convert the .voc to a .tzx file using the following command in the DOS-prompt: voc2tzx /pilot 250 a.voc a.tzx
Note: If an error occurs you may need to adjust the pilot value or take the default value. 250 worked best for me.
8. Test the output TZX file in the Spectrum Emulator,
9. If the TZX file works, snapshot the file to a Z80 file at an appropriate moment in the Emulator for portability.

At the time of writing X128 is the only emulator capable of reading .TZX files and saving .Z80 files on the PC and this is why I have mentioned it. I found this to be an extremely useful technique to preserve programs that I have written on the Spectrum.

Additional Information

Hardcore Spectrum users use a combination of a real Spectrum, MGT +D and Multiface to convert Spectrum software. The MGT +D writes onto standard IBM 720k floppy discs, which is better for reading on a PC than the Amstrad 3 inch disc format provided by the 128k+3. To convert multipart software this may be the only technique guaranteed to work, possibly also requiring an in-depth knowledge of the Z80 processor to get snapshot points just right and to fix-up multipart loaders.

This technique removes the reliance on real Spectrum hardware, which is useful because there is so little of it around these days. The only problem with TZX format is rather spartan support. Most software is saved in .Z80 or .SNA format for portability across different emulators. I don't know if simply recording a VOC and using taper or voc2tzx fixes all of the issues surrounding protection and multipart loaders but it works for a lot of cases.

Never copy copyright material without permission. This technique is useful for those that wish to preserve their software on hardware that is still supported.

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