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Discussion Starter · #1 ·
I have been trying to get custom resolutions for games to work, and after reading as many posts on the issue as I could find it sounds like 1280x1024 should be perfect. It should fill up my whole screen with little to no vertical overscan.


However, I am confused and must be missing something. First of all after reading a post called "DEFINITIVE GUIDE: Displaying Custom Resolutions on HDTV!" I was very enlightened to how things work. However when creating a custom 1280x1024 resolution with the timings posted in Karnis's sticky, I get a vertical line total of about 1133. Acording to that old definitive guide post, the vertical line total for 1080i is supposed to be 563 as it is suggested that powerstrip only work on frames not fields? Is this no longer true and that is why the vertical total is 1133?


So ignoring that for the moment when I use 1280x1024, I have no horizontal overscan whatsoever. It looks gorgeous! However, my veritcal overscan is very odd.... In the 16x9 window that my 4:3 TV Sony HS510 sets up(Yes I know jump removes that compression), It is only scanning in the top 65% of this 16x9 window. The bottom is just black. I have checked the service menu and it is running 1080i... so any idea whats going on? Is this overscan? Underscan? I am really confused how it could be underscanning but also cutting off a large section of the picture. I mean with 1280x1024 in 1080i mode shouldn't that mean I have a tiny bit of underscan as 1080i is using move lines of vertical resolution then 1280x1024 is giving it?


When I run a game in 1280x1024 the bottom 35% is still black.... I just want to get the full picture on the screen, even if it letterboxes it a little, however, it is literally not display in a section of that window. In fact the section missing from measuring constitutes the rest of the image on my computer moniter except for maybe a few % overscan which I would be fine with!


P.S. I was also testing the 1024x768 timings given, but my set doesn't run it under 1080i it runs it in 720p, which it of course upconverts. So I dont get underscan I get overscan... any way to force the 1024x768 res to run in 1080i?
 

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Discussion Starter · #2 ·
Anyone? I am so confused because I guess its some serious underscan about 30% or so.... As I said its like 30% of the display simply isn't being used. This exact thing is happening in any 1280x(whatever) I am trying to make.... this makes no sense to me as all posts I have read have said that 1280x1024 was the best gaming resolution with only a little overscan. How am I getting horrible underscan then??
 

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Hi Toth,

I can help you with the vertical line problem, but not much else. You must have missed the part in his definitive guide that talked about interlaced line totals? 563 is for progressive, 1125 is the total needed for interlaced resolutions. He talks about it in one of the blocks of info right after the very first batch of resolutions & timings. Hope that helps.
 

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Discussion Starter · #4 ·
Hmm ok, I was confused though because I thought he said powerstrip wants the line number in frames even if it is interlaced but I must have misread it. Thanks for clearing that up.


Anyone have any ideas on my problem which I guess is underscan? I have nearly fully usuable rez, but I can't figure out why its not using the bottom 30% of the display window.
 

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Discussion Starter · #6 ·
Nah I am using the ATi 9800 pro AIW with the in box dongle... I am so lost at this point... I don't know what to mess with and I am afraid I am going to hurt my TV... It sucks being this close...


Anyone know at least how to force a custom timing of 1024x768 in 1080i? As I said mine is putting it in 720p thus creating overscan. I wouldn't mind a bit of underscan as long as the whole thing as being displayed.


As for 1280x1024... does that actually sound like underscan? Seems wrong to me... the whole screen isn't being displayed and part of it is just black... most underscan I have read about sounds like the whole screen is being displayed, but the whole TV display isn't being used....
 

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Yes, it is underscanned. On a 1080i HDTV, you have 1080 interlaced lines to work with, and the rez you are working with only has 1024 interlaced lines, therefore the difference is distributed to the vertical blanking area...black bars.

There is a 1024x768i (using 1080i timings) posted in the guide stuck at the top of the page, read the whole first post carefully. It will be severely underscanned.
 

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Discussion Starter · #8 ·
I understand that Karnis, but then why arn't I getting the whole image when I run a game in 1280x1024? I am only getting the upper 70%, the bottom is cut off. I thought if it was underscanned, then that would just be extra room, as nothing will be displayed there. For instance I tried the call of duty demo in 1280x1024, and it only displayed from the top down to sight on the gun. The entire bottom was cut off. If my vertical line count on the tv is 1080, shouldn't the image easily display its 1024 lines within this?


Also every post that talks about 1280x1024 suggests a bit of vertical overscan... Nintari suggested that in his custom timings post. That doesn't seem right to me, but I don't know what else to go on.
 

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Might be an issue with the vertical compression your set uses when squeezing a 16x9 signal. Back in my gaming days I didnt have this problem. In fact, using the VGA breakout cable, I tested the CAT 3.4 drivers for all interlaced rez and all interlaced rez up to 1776x1000i, I could clearly see the taskbar on the bottom of the desktop and all of the top...no cropping at all on my 16x9 Mits. Most HDTVs, due to inherent overscan, can only display ~960-1000 interlaced lines. I remember reading somewhere that these sets only display about 810 lines or so when doing a 16x9 squeeze. Try 1152x864i or 1280x720i and see what happens.

All the vertical line totals for interlaced rez I posted are 1125.
 
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