Difference between revisions of "OSSC potential incompatibilities"
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! align="left"|Console | ! align="left"|Console | ||
! align="left"|Reason | ! align="left"|Reason | ||
| + | ! align="left"|Fix if any | ||
! align="left"|Test method | ! align="left"|Test method | ||
|- | |- | ||
|NESRGB / SNES in 60Hz mode | |NESRGB / SNES in 60Hz mode | ||
|Hsync period is not constant, causing some jitter to output clock. Some displays are sensitive to this and cannot properly lock to the signal (low receiver PLL bandwidth). | |Hsync period is not constant, causing some jitter to output clock. Some displays are sensitive to this and cannot properly lock to the signal (low receiver PLL bandwidth). | ||
| + | |[https://shmups.system11.org/viewtopic.php?f=6&t=61285 De-jitter modification] | ||
|No known external test method. | |No known external test method. | ||
|- | |- | ||
|Neo Geo | |Neo Geo | ||
|264-line output becomes 528 when linedoubled. MVS additionally outputs 59.18Hz refresh rate. | |264-line output becomes 528 when linedoubled. MVS additionally outputs 59.18Hz refresh rate. | ||
| + | |Crystal swap for refresh rate normalization | ||
|<pre>ModeLine "MVS_240p_x2" 26.810 720 736 798 858 480 489 495 528 -hsync -vsync</pre> | |<pre>ModeLine "MVS_240p_x2" 26.810 720 736 798 858 480 489 495 528 -hsync -vsync</pre> | ||
|- | |- | ||
|PSX in 50Hz non-interlaced (288p) mode | |PSX in 50Hz non-interlaced (288p) mode | ||
|314-line output becomes 628 when linedoubled. | |314-line output becomes 628 when linedoubled. | ||
| + | |Dual-frequency oscillator (DFO) for refresh rate normalization | ||
|<pre>ModeLine "PSX_288p_x2" 27.000 720 732 796 864 576 581 587 628 -hsync -vsync</pre> | |<pre>ModeLine "PSX_288p_x2" 27.000 720 732 796 864 576 581 587 628 -hsync -vsync</pre> | ||
|- | |- | ||
|PAL Saturn in 60Hz mode | |PAL Saturn in 60Hz mode | ||
|59.37 Hz vertical refresh rate | |59.37 Hz vertical refresh rate | ||
| + | |Dual-frequency oscillator (DFO) | ||
|<pre>ModeLine "PAL_Saturn_240p_x2" 26.794 720 736 798 858 480 489 495 526 -hsync -vsync</pre> | |<pre>ModeLine "PAL_Saturn_240p_x2" 26.794 720 736 798 858 480 489 495 526 -hsync -vsync</pre> | ||
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|- | |- | ||
|Jaguar in 50Hz non-interlaced (288p) mode | |Jaguar in 50Hz non-interlaced (288p) mode | ||
| − | |Output uses | + | |Output uses constant ''even'' field indicator since boot, OSSC can't lock properly |
|AV3 input (different sync processing chain) e.g. with Sync Strike | |AV3 input (different sync processing chain) e.g. with Sync Strike | ||
|- | |- | ||
Revision as of 19:12, 2 September 2019
Incompatibility due to display tolerance
Below are listed consoles which may be incompatible with certain displays when used with OSSC. Home computers and more exotic arcade boards are not included since their outputs often deviate from PAL/NTSC spec to a degree that they are not generally compatible with TVs but with PC monitors only. Capture card compatibility is neither considered since with some exceptions they are the most picky devices when it comes to non-standard refresh rates and line counts.
As a rule of thumb, consoles with linedoubled output with >1 scanlines off 525/625 line spec or >0.5Hz off 50/60Hz refresh can be considered potentially incompatible for displays.
| Console | Reason | Fix if any | Test method |
|---|---|---|---|
| NESRGB / SNES in 60Hz mode | Hsync period is not constant, causing some jitter to output clock. Some displays are sensitive to this and cannot properly lock to the signal (low receiver PLL bandwidth). | De-jitter modification | No known external test method. |
| Neo Geo | 264-line output becomes 528 when linedoubled. MVS additionally outputs 59.18Hz refresh rate. | Crystal swap for refresh rate normalization | ModeLine "MVS_240p_x2" 26.810 720 736 798 858 480 489 495 528 -hsync -vsync |
| PSX in 50Hz non-interlaced (288p) mode | 314-line output becomes 628 when linedoubled. | Dual-frequency oscillator (DFO) for refresh rate normalization | ModeLine "PSX_288p_x2" 27.000 720 732 796 864 576 581 587 628 -hsync -vsync |
| PAL Saturn in 60Hz mode | 59.37 Hz vertical refresh rate | Dual-frequency oscillator (DFO) | ModeLine "PAL_Saturn_240p_x2" 26.794 720 736 798 858 480 489 495 526 -hsync -vsync |
Incompatibility due to sync characteristics
Below are listed consoles which are incompatible with OSSC's default settings regardless of display. Some are simply fixed by a menu setting, others may need extra hardware.
| Console | Reason/symptom | Fix if any |
|---|---|---|
| Neo Geo MV-1A and MV-1FZ | Significant hsync period variation during vblank | H-PLL pre and post coast -> 3, Hsync tolerance -> 10us (or higher) |
| Jaguar in 50Hz non-interlaced (288p) mode | Output uses constant even field indicator since boot, OSSC can't lock properly | AV3 input (different sync processing chain) e.g. with Sync Strike |
| PSX SCPH-100 (unverified) | No sync detected? | |
| RGB modded French N64 (unverified) | Unstable sync regardless of settings? |
Other incompatibilities
Consoles/hardware with other issues are listed here.
| Console | Reason/symptom | Fix if any |
|---|---|---|
| Sega Megadrive Mk1 | Bad audio quality using Stereo RGB cable with headphone socket audio | Fixed in latest firmware. Affects OSSC 1.6 only |
