Read a SAS data file into R based on a SAS script (NHANES III)

[songkkkz]

I am attempting to read NHANES III, a publicly available epidemiological dataset.
It is not clear how to do this but they do provide a data file and a SAS file:
https://wwwn.cdc.gov/nchs/data/nhanes3/1a/adult.dat,
https://wwwn.cdc.gov/nchs/data/nhanes3/1a/adult.sas.
The data file does not seem to be a conventional SAS export format. and the SAS file seems to describe its format with LENGTH, FORMAT, INPUT and LABEL headers.
Any idea how to read this into a friendly format?

[technocrat]

A well-known dataset like this almost always has an R package to handle conversions. In this case nhanesA should fit the bill.

[songkkkz]

However, the nhanesA package seems to only download XPT files of the database after 1999.

[technocrat]

NHANES practice is to release data as SAS transport files, which can be read directly by a number of applications. FAQ.

The purpose of nhanesA is to convert those XPT files into R tables.