256p and 288p vertical games on horizontal 14" CRT TV

[quartex73]

Hi all.

First: sorry for my english.

My setup is:
14" TV CRT 15Khz Philips 14pt1501 (horizontal)
Windows 7 64 bit
AMD Radeon R9 380
crt_emudriver_&_tools_2.0_beta_15_18.5.1_W.7-64

Using groovymame 0.229 and super resolutions.
Arcade_15

I Used mode 2560x240 for horizontal centering in Arcade OSD,
avoiding stretching (I only moved Hcenter from 52/65 to 45/65).

So in mame.ini I modified the default
crt_range0   15625-16200, 49.50-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 192, 288, 448, 576

in:
crt_range0      15625-16200, 49.50-65.00, 3.070, 4.758, 6.907, 0.064, 0.192, 1.024, 0, 0, 192, 288, 448, 576

(by the way, is correct to modify in mame.ini the pulse sync value too?)



About vertical games 256p and 288p I'm experiencing of course some cutoff and some weird zigzag effect.
See screenshots:

donkey kong 2560x256


1942 2560x256


digdug 2560x288



Looks like 256p is worse than 288p, and I'm surprised about that (and I can't understand why).
With 256p there is terrible zigzag in the bottom (look at mario in donkey kong...)
With 288p there is some zigzag in the top

Since my goal is pixel perfect and I'm ok with some cutoff I tried to fix the zigzag effect.

For 2560x256 in arcade OSD I moved both Vfront and Vback (Vfront from 2 to 1 and Vback from 16 to 1).
I did horizontal centering too.

Then I created a vertical.ini:

crt_range0      15625-16200, 49.50-65.00, 3.120, 4.992, 7.487, 0.066, 0.197, 0.066, 0, 0, 256, 256, 448, 576
crt_range1   15625-16200, 49.50-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 192, 255, 448, 576
crt_range2   15625-16200, 49.50-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 257, 288, 448, 576

crt_range0 (with modified values from arcade OSD) for 256p
and crt_range1 and crt_range2 for all other vertical resolutions (same values as crt_range0 in mame.ini).

And this is the result I get for vertical 256p (donkey kong, 1942).





Is this the right way to fix my issue for pixel perfect?
Since I touched directly Vfront and Vback in arcadeOSD, I presume this is not anymore pixel perfect, isn't it?


Is there anything different I can do?
I presume there is no way to avoid cutoff at least for 256p mantaining pixel perfect.

Thanks in advance for your help and your tips

[makya]

If your TV is EURO you can display "pixel perfect" 288 lines, but not at 60 Hz.

At 60 Hz, you will get 240 lines, maybe 244 MAX. In your case I would display 240p with option intoverscan activated.

# CORE RENDER OPTIONS
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intoverscan             1