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Reply To: Tips & Tweaks: Lx3, Lx4, Lx5 modes

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#11435

Harrumph
Participant

Might have gone down the rabbit hole with this one, or will it be a wild goose chase…? Checking VESA timings, making spreadsheets. 🙂

I’m starting to think display pixel clock tolerance might be one of the most important factors for these picky TVs. When horizontal freq is known, like in @blockaboots case, the wanted pixelclock can be referenced with VESA timings standards spreadsheet (google CVT1.2Generator).
Then one can calculate the needed H.Samplerate (given the fixed linecount and H/V. refresh coming from OSSC). However, as this approach is dependent on scanline output and V.Refresh, it could be different from console to console.

I probably should have put in the above post, I only used my modded 2-chip SNES for the above settings for my TV (outputs 262 lines, V.Refresh around 59.6Hz).

As I mentioned, working on a spreadsheet. For example, for BlockABoots 1280 x 1024 (64.0kHz, 60Hz), this implies older VESA standard (no reduced blanking), which wants 109MHz pixel clock. So he could try:

Console lines | 262  | 263  | x4 mode
H Samplerate  | 1734 | 1727 |
H Active      | 1280 | 1280 |
H Sync        |  158 |  156 |
H Backporch   |  198 |  196 |

Would link spreadsheet but it’s not finished so just throwing this out as an example. As I said, this might be a wild goose chase… Check back tomorrow.