Hello
Two Adapters required for Holden VS and VR
Using a Tech1 or Tech1A scan tool
This information from genuine Holden Adapters
Tested and operating OK

Hello this is the TECH1A main EPROM inside the TECH1A unit
It is Version 4.0 from a late model unit 1998 it will upgrade older Tech1A units
But will not work in Tech1 units