read the configuration file documentation

Could you be more specific?

If I look in the documentation folder I have the nothing that says "configuration file."

If you are referring to the help in the config file:

1#   fullresolution: What resolution to use for fullscreen: original or fixed size (e.g. 1024x768).
2#                     Using your monitor's native resolution with aspect=true might give the best results.
3#                     If you end up with small window on a large screen, try an output different from surface.

then using

fullresolution=1920x1080
aspect=true
scaler=tv2x forced

does not stretch the screen fully and does not display even scanlines with any of the outputs: surface, overlay, opengl, openglnb OR ddraw.

This is why I posted here.

the manual and the readme in the documentation folder you have mentions "configurations file" over 50 times, so maybe try visiting eyes doctor...

http://www.dosbox.com/wiki/Scaler
it looks scan2x has more visible scanlines than tv2x
and 3x even more.

opengl and overlay doesn't upscale all scalers
ddraw upscales all scalers, but it doesn't work with latest nvidia drivers in winVista/7 (you said nothing about your gfx card)
so check them without using any scaler first.
If you are talking about black collumns on left and right - they have to be there to keep proper aspect (otherwise all characters and everything would be "fat" when standing and very thin and long when lying, ,and totally distorted when bowind down 😉

ddraw upscales all scalers, but it doesn't work with latest nvidia drivers in winVista/7 (you said nothing about your gfx card)

Good point 😀 My graphics card is a GeForce GTX 260 running on the lastest nvidia drivers in Win 7!

The black columns are above, below, left and right; the scanlines are uneven in most cases.

ddraw appears to be the answer to my prayers but why doesn't it work with the Win 7 drivers?

If HLSL shaders could be implemented then scanlines can be added AFTER scaling and all would look great:

1#define LINES_ON      1
2#define LINES_OFF     1
3#define OFF_INTENSITY 0.5
4
5float2 TextureSize;
6float2 InputSize;
7float2 OutputSize;
8
9texture Texture;
10
11sampler sourceSampler = sampler_state
12{
13   texture = <Texture>;
14   
15   MagFilter = LINEAR;
16   
17   AddressU  = CLAMP;
18   AddressV  = CLAMP;
19};
20
21float4 Ps(float2 texCoord : TEXCOORD0) : COLOR
22{
23   float pixelRatio = OutputSize.y * (TextureSize.y / InputSize.y);
24
25   return tex2D(sourceSampler, texCoord)
26      * (floor(texCoord.y * pixelRatio) % (LINES_ON + LINES_OFF) < LINES_ON ? 1.0 : OFF_INTENSITY);
27}
28
29
30technique T0
31{
32   pass P0
33   {
34      PixelShader = compile ps_2_0 Ps();
35   }
36}