If you do not have access to old Microsoft Works, it can be really tricky to convert the old .wps documents to something else, even just plain text files via wps to txt conversion. Some word processors may still support this format and re-save it to multitude of other document formats, or even plain text files.
You may also find dedicated text converters, or even specialized Works converters, but those generally save to RTF, because this format can be further converted to many other formats.