Mac Mini G4 + display oddities

[ssp3]

OK, I spoke too soon: I still do not get 1920x1200@60Hz over the VGA port of the DELL U2412M monitor with the ATI Via Driver: It still only shows the option @76Hz instead, all other resolutions at @60Hz are lower. I have a small VGA-to-DVI converter on the mini side, which I always used successfully with a CRT monitor. Also, my monitor is only identified as "VGA Display" in the Control Panel, just like before, instead of "DELL U2412M". It is weird we have the same minis and monitors, yet the results were different. Different VGA-to-DVI adapters? Different VGA cables?

1. Make sure you have correct ROM / ATI Extensions / driver combination as I outlined in my previous post. Check modification dates, if in doubt.
2. Reset PRAM. Maybe even using OF commands.
3. Pull all other cables, except VGA from your display, just in case.
4. Try other adapters and VGA cables.
5. It could be that it is down to display revisions. Mine are relatively new - 2017, 2018 and 2021.


EDIT. I have a feeling that you have extensions that are fighting each other. Try the minimal set that I describe in the post below.

[ssp3]

Additional notes on my tests.

1. As can be seen from my posted screenshots, I am using only minimal set of ATI extensions to test for 2d acceleration. There are three plus driver extension, when needed.

2. darthnVader modified 3 extensions - ATI Resource Manager, ATI Graphics Accelerator and ATI 8500 3D Accelerator. And ATI Via Driver, of course.
I am leaving out ATI 8500 3D Accelerator in my tests. To spot modified extensions, check their modification dates - they are from 2018.

3. One other extension needed for graphics stuff to work is ATI Extension. It remains unmodified. I have tested several older versions (back to as far as 2001) and they all work.

4. Important! If you remove ATI Extension, but leave all other ATI extensions in place, you will get black screen. At least it happened to me when I tested with v8 ROM.

[ssp3]

Aluminium Cinema HD Displays

Testing both the 23" (1920x1200) and 20" (1680x1050) models of the display independently; the results are the same.
Both connect over a hard-wired DVI cable and are recognised as "Cinema HD" in the Monitors Control Panel.

Oh, Cinema HD Displays 

These two are listed in Mac Mini G4 documents as compatible, so, no surprise they're working.

OT. These are the older, non LED backlight models. How are they aging in terms of brightness, uniformity and color?

[RossDarker]

Oh, Cinema HD Displays 

These two are listed in Mac Mini G4 documents as compatible, so, no surprise they're working.

OT. These are the older, non LED backlight models. How are they aging in terms of brightness, uniformity and color?

Yes they’ve always been working fine for OS 9 on the mini, just not with ‘RockHopper2 Driver’.


These matte displays are holding up well. The 23” one was bought in 2008. Having been in use since, there are these slight streaks of burn-in at the very bottom of the display, but this isn’t noticeable unless you’re looking for it with a blank background.

My 20” one is completely fine; bought this one several years ago, initially for the Mac mini in fact. Of course, it’s been used with various other computers since too. No burn in there, brightness seems to be as I remember, and the colours are fantastic on both.

Great monitors for their age!

[ssp3]

Schlepped home another Dell display to test it with Mini. This one is higher quality version of 2212 from their "Ultrasharp" line.

Dell 22" U2212HM + 1.5 GHz Mini

Native display resolution - 1920 x 1080 @60Hz (16:9)
IPS type panel
VGA + DVI + Display Port inputs.
v8 ROM
Test conditions identical to my previous tests

1. DVI to VGA, ATI RockHopper2 Driver - black screen.

2. DVI to VGA, no driver - 800 x 600, no acceleration.

3. DVI to VGA, ATI Via Driver - max resolution, acceleration works.
Display is recognized correctly as Dell U2212HM





4. DVI to DVI, ATI Via Driver - black screen. Similar to my test with v9 ROM in the first post.

5. DVI to DVI, no driver - 1920 x 1080, no acceleration. Display is recognized as Color LCD.

6. DVI to DVI, ATI RockHopper2 Driver - max resolution, acceleration works.
Display is recognized as VGA (!) despite being connected over DVI.





As can be seen, the results are identical to those of the other version of Dell 2212.

I think that either Dell displays report to graphic chips/cards in a certain way and that's why Minis are so finicky with them or there might be a problem with Full HD 16:9 displays in general.

If anyone else is using 1920x1080 display with his Mini, please chime in.

[ssp3]

Still talking to myself..

To complement what I wrote about similar combination and OS9  >  http://macos9lives.com/smforum/index.php?topic=7048.msg54411#msg54411

Dell 22" U2212HM + 1.25 GHz Mini

Native display resolution - 1920 x 1080 @60Hz (16:9)

DVI to DVI cable.

Mini is running "naked". No DVD drive, no Mezanine, Bluetooth or AirPort boards.
Boot drive - 128GB 2.5" "stripped" Samsung SSD on a cheap JMicron adapter. (My standard setup).

OSX 10.5.8 Leopard

Boot into OpenFirmware
First attachment. One can barely see command line prompt.

Boot into Leopard
Second attachment. Same problem.

Boot into Leopard, VGA cable + adapter
Third attachment. Note the odd aspect ratio. It becomes normal when OSX drivers kick in.

It looks to me that first generation Minis have problems communicating to Full HD 1920 x 1080 displays when connected over DVI in OSX too.
At least to those manufactured by Dell. VGA adapters are OK.

This might be the real reason why Apple silently upgraded G4 Minis and their ROMs - upcoming OS and modern display compatibility!
What's the point of having digital (DVI) connection on your product, if it doesn't work with Full HD displays that are gaining popularity? 

Of course, to be 100% sure, more user reports are needed !

[aBc]

Of possible relevance here … per darthnVader.

Mac Mini G4 pixel clock limited to 135Mhz   / April 1, 2018
https://macos9lives.com/smforum/index.php?topic=4337.msg30099#msg30099

Display Support:   Single Display   Resolution Support:   1920x1200
Details:   The DVI video output supports digital resolutions up to 1920x1200. Apple also reports that it supports the "20-inch Apple Cinema display and 23-inch Apple Cinema HD display; supports coherent digital displays up to 154MHz; supports non-coherent digital displays up to 135MHz." VGA output (using the provided adapter) supports analog resolutions as high as 1920x1080. S-Video and composite video (to connect to a projector or TV) requires the Apple DVI to Video adapter (sold separately).


Coherent vs non-coherent is some obscure thing to do with the TMDS transmitter( on the GPU ) and the TMDS receiver in the display. The 9200 either has an issue with a weak TMDS signal with non-coherent receivers( Displays ). Or Apple crippled it, tho I doubt that.

The trouble is, no manufacturer really list that in the specs, and I doubt you'd get anyone in tech support to know what you were talking about if you did call them.

So it's really a crap shoot as to what brand and make of display will work correctly at the native res of the LCD/LED. My 1080p HDTV works fine with the Mini @720p, as the pixel clock is not over 135Mhz at that resolution.

[ssp3]

Of possible relevance here … per darthnVader.

Mac Mini G4 pixel clock limited to 135Mhz   / April 1, 2018
https://macos9lives.com/smforum/index.php?topic=4337.msg30099#msg30099

Well, the same Dell 1920 x 1080 display works just fine with 1.5Ghz Mini in OSX Leopard.

Besides,
* 1920 x 1080 Dell has 148.5 MHz pixel clock
* 1920 x 1200 Dell has 154.0 MHz pixel clock.

I'm curious where does the 135 MHz figure comes from.

[aBc]

I'm curious where does the 135 MHz figure come from.

Perhaps you should ask (or invite) darth to comment here?

Not quite certain what you’re really expecting from the 2005 Mac minis (with fixed 32mb or 64mb of VRAM) originally designed to work with Apple monitors. Sure, they will work with some other monitors, but not always and not at all resolutions, nor connection variants.

But I do hope you find your answers and any possible solutions.

[ssp3]

Perhaps you should ask (or invite) darth to comment here?

He was last seen here almost a year ago..

Not quite certain what you’re really expecting from the 2005 Mac minis (with fixed 32mb or 64mb of VRAM) originally designed to work with Apple monitors.

I do expect them to work with more or less modern displays. Not necessarily with 4k, but at least with Full HD.
I see no point of hot-rodding these Minis - overclocking, SSD drives, copper heatsinks and so on if at the end of the day one could only connect them to old and slowly fading CCFL backlight displays, no matter of what brand.
1920 x 1080 + LED backlight is the norm today, smaller resolutions of decent quality cost extra.

[ssp3]

For those who don't want to read the whole thread but are after quick answers.
These are my test results as of today.
NOTE. OS9 tests were run using v8 ROM file and appropriate extensions.




Note the strange setting required for Dell P190S to work with RockHopper driver. I have a feeling that somewhere some resolutions table is off in that driver.


* I made a table in Apple's Numbers which I will update as soon as I have any new data. If someone has other test results, just let me know and I will happily add them.