darkpanda
Dark Prince
- Joined
- Oct 28, 2007
- Messages
- 823
I don't think the concept of "external calls", such as dynamic calls to DLLs, existed in MS-DOS... I've read someone created a TSR (a resident program) that runs in the "background" and can interact with the foreground program through interrupts, but I really have no idea about how that works - for the moment...
The TSR I'm talking about was done especially for CIV, to add custom "special resource" squares, and used by Dack for the "64-pop" city (can't find the thread right now).
Anyway, the overlay mechanism already does this: re-read CIV.EXE, select an overlay, then load it inside segment 20... So adding a new overlay definitely seems like the shortest route to adding code... Plus you get to have access to CIV data directly, if you need to.
The TSR I'm talking about was done especially for CIV, to add custom "special resource" squares, and used by Dack for the "64-pop" city (can't find the thread right now).
Anyway, the overlay mechanism already does this: re-read CIV.EXE, select an overlay, then load it inside segment 20... So adding a new overlay definitely seems like the shortest route to adding code... Plus you get to have access to CIV data directly, if you need to.
