Why is this resolution "inaccessible"?

[Roland Scheidegger]

Gene Heskett wrote:
>> The 320x240 mode requires a hsync value of 15kHz yet you've got the
>> lowest to be 28kHz in your config file.
>>
>> You'll need to try and lower it.
> 
> WARNING
> 
> This is VERY VERY UNSAFE for the monitor, and will have a high 
> probability of letting all the smoke out.  Many of the low dollar types 
> are so closely engineered that even 28khz is overheating them.
....
Makes sense but I have not seen a monitor in about 15 years which would 
even try to sync to a frequency that far out its specfied frequency 
range. (And if you have one such beast, maybe it's a good time now to 
upgrade to a new one anyway :-)). Or could this potentially affect 
modern multisync monitors too?
That said, your typical monitor indeed absolutely will not support 
15khZ, all those vga multisyncs usually support 30-something as hsync range.
320x240 usually has the same timings as standard vga though, since the 
chips are capable of something called doublescan (basically scan out one 
pixel as four). Don't know if the i810 chips / drivers support this.

Roland