Unfortunately, now Rockstar Games is not particularly thrilled about its legacy. If a GTA 3 still somehow remembered, then the older parts were completely forgotten. Previously, they could be downloaded officially on the R* website (mirror of that page) and even buy it on Steam, but now … Fortunately, the enthusiasm for the classic Grand Theft Auto does not fade away. Even the authors of the original games.
For example, Mike Dailly, one of the founders of DMA Design (now Rockstar North), author of the first GTAs, spoils us on your blog, dedicated mainly to the Lemmings series, but information regarding other works is also published. Previously, there was laid out a document that describes the concept first GTA. It is dated May 1995 and contains 12 pages.
Download / read official GTA 1 documentation
Recently, the developer added to the archive a similar document related to the creation GTA 2. It was compiled in 1998-1999, distributed with the mark “Confidential” and consists of as many as 85 pages.
Download / read official GTA 2 documentation
Source: gta.com.ua