Digital Tomica (デジタルトミカ) was the Tomica counterpart to the Digital Plarail games released by Tomy for Windows 3.1, 95, and later NT in the later 1990s and into the early 2000s. The original 10,000 run of Digital Tomica came packaged with a silver-plated Nissan Skyline GTR Tomica with Digital Tomica text. This release and car can be seen on this website. In addition to being able to plan out combined Tomica and Plarail layouts with both games installed, one vehicle expansion pack and a building pack that also included Digital Plarail elements were also released, and both games were combined and rereleased as Digital Plarail & Tomica DX in 1998.
The initial Digital Tomica release was in April 1997 for Japanese-language Windows 3.1 and 95. The disc comes in a CD jewel case originally sold in a larger cardboard box - the first (and only?) run of 10000 copies included a silver Nissan Skyline. I don't currently own the larger cardboard box, just a few copies of the CD in its jewel case.
Digital Tomica installs as version 2.0, and will upgrade Digital Plarail to version 2.0 if it is installed (as well as integrating both pieces of software).
The title of the disc is PLA_10, implying it came out after Digital Plarail Vehicle Set 03 Cargo Edition and before the Digital Plarail & Tomica DX combined pack. Files on the disc date to November 1997.