I need help for width vertical slotmask for non integer

I need help for width vertical slotmask for non integer scale

Example slotmask width for megadrive 320p on 1465x1080 resolution

2pixels = 732 line vertical

3pixel = 488 line

4pixel = 366 line

5pixel = 293 line

6pixel = 244 line

Now I want to

How to draw 320 line vertical on 1465x1080?

How to draw 640 line vertical like my crt on 1465x1080?

What are more accurate 320 line or 640 line ?

My screen resolution is 2460 x1080

Sorry for my bad English.