How do you determine at runtime whether a program was started in 40 or 80 column screen mode?  I don't want to force the user to pick one or the other, just adapt to what they were using.  I'm writing a prototype in basic, but will be porting it to C.  I need to dynamically size some screen elements to fit on 40 columns, but I don't want to force the limited screen layout on 80 column users.

Payton

v=RGR (n)

In assembly,


BIT $D7
BMI 80column


Quote from: Payton Byrd on April 20, 2010, 10:32 AM
How do you determine at runtime whether a program was started in 40 or 80 column screen mode?  I don't want to force the user to pick one or the other, just adapt to what they were using.  I'm writing a prototype in basic, but will be porting it to C.  I need to dynamically size some screen elements to fit on 40 columns, but I don't want to force the limited screen layout on 80 column users.

Payton

You need to start perusing some of the literature available here.  A good start would be Mapping the Commodore 128.