In 1983, TSR published the module UK1: Beyond the Crystal Cave. It was written by Dave J. Browne, Tom Kirby, and Graeme Morris, and illustrated by Dave De Leuw and Timothy Truman. It consisted of a 32 page booklet and folding cover with maps.
This conversion guide allows DMs to run the original module with 5th Edition rules and provides a reference sheet for encounters. It is intended for 4-6 characters of levels 4-6.
To use this conversion guide you will need a copy of "UK1 Beyond the Crystal Cave".