iMac Resolution Issue

[Eric Dunbar]

The more I read your earlier posts, the more I discover :-).

On 10/26/05, MrKnisely <mrknisely at mrknisely.is-a-geek.org> wrote:
> Found something of interest in my /var/log/Xorg.0.log file:
>
> (!!) ATI(0): Virtual resolutions will be limited to 2047 kB
>  due to linear aperture size and/or placement of hardware cursor image area.
> (II) ATI(0): Using Block 0 MMIO aperture at 0x80881400.
> (II) ATI(0): Using Block 1 MMIO aperture at 0x80881000.
> (II) ATI(0): MMIO write caching enabled.
> (--) ATI(0): 2048 kB of SGRAM (1:1) detected (using 2047 kB).

If you'll notice, you have only 2 MB of Video RAM (2048 kB of SGRAM)

> (WW) ATI(0): Cannot shadow an accelerated frame buffer.
> (II) ATI(0): Engine XCLK 82.676 MHz;  Refresh rate code 6.
> (--) ATI(0): Internal programmable clock generator detected.
> (--) ATI(0): Reference clock 157.5/11 (14.318) MHz.
> (II) ATI(0): iMac: Using hsync value of 60.00 kHz
> (II) ATI(0): iMac: Using vrefresh range of 75.00-117.00 Hz
> (II) ATI(0): Maximum clock: 165.00 MHz
> (II) ATI(0): Not using default mode "640x350" (hsync out of range)
> (II) ATI(0): Not using default mode "320x175" (hsync out of range)
> (II) ATI(0): Not using default mode "640x400" (hsync out of range)
> (II) ATI(0): Not using default mode "320x200" (hsync out of range)
> (II) ATI(0): Not using default mode "720x400" (hsync out of range)
> (II) ATI(0): Not using default mode "360x200" (hsync out of range)
> (II) ATI(0): Not using default mode "640x480" (hsync out of range)
> (II) ATI(0): Not using default mode "320x240" (hsync out of range)

This lot of errors is standard. These settings won't be supported by
the iMac hardware (it supports only three!!!...  I'm sure you could
find out which ones on the web)

> (II) ATI(0): Not using default mode "1024x768" (insufficient memory for
> mode)

This is what is key! It's trying 1024*768 at 24 bit. Now to get it using 16 bit.

> (II) ATI(0): Not using default mode "2048x1536" (insufficient memory for
> mode)
> (II) ATI(0): Not using default mode "1024x768" (insufficient memory for
> mode)
> (II) ATI(0): Not using mode "800x600" (no mode of this name)

Hmm. There's a problem here. *Why* is 800*600 not working? Perhaps it
should be 832*624 (this is rare early Mac-only (well, it was supported
by non-Macs but not particularly common) resolution)?

> (--) ATI(0): Virtual size is 512x384 (pitch 512)
> (**) ATI(0):  Default mode "512x384": 39.4 MHz, 60.1 kHz, 75.1 Hz (D)
> (II) ATI(0): Modeline "512x384"   39.40  512 520 568 656  384 384 386
> 400 doublescan +hsync +vsync

So, this is what you're running. Welcome to the Mac 128-Mac Classic II
era :-) (512*342).

No suggestions, but hopefully I provided you with new info.

Eric.