Commodore 128 Alive!

Commodore 128 => 128 programmers => VDC Programming => Topic started by: Payton Byrd on April 20, 2010, 10:32 AM

Title: Determining screen mode
Post by: 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
Title: Re: Determining screen mode
Post by: wte on April 21, 2010, 07:37 AM
v=RGR (n)
Title: Re: Determining screen mode
Post by: Hydrophilic on May 06, 2010, 08:38 PM
In assembly,


BIT $D7
BMI 80column

Title: Re: Determining screen mode
Post by: BigDumbDinosaur on May 09, 2010, 06:52 AM
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.
EhPortal 1.34 © 2025, WebDev