This seems like a valid concept that's orthogonal to yesterday's discussion: 
external tools plugged into the SPI port to crack the chicken-and-egg problem 
(and possibly do other things).  If this 4-way mode selection were implemented 
on OGC1, the external tool would be the method of getting that custom mode into 
NVRAM, so that it could be selected by the on-board switches.
   I don't know whether there's any plan to include jumpers or DIP switches on 
OGC1, but one bank of 4 or so is a lot easier to justify than enough switches 
to completely express all possible modelines.


 -------------- Original message ----------------------
From: James Richard Tyrer <[EMAIL PROTECTED]>
> Timothy Miller wrote:
> > On 8/1/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> > 
> >>    The way si87 did it was to provide a DIP switch for boot mode 
> >> selection.  4 bits on the DIP switch select stored modes for various 
> >> common fixed frequency monitors, with mode 0 being VGA and I think 
> >> mode 4 being the A1097C.  These modes are loaded in flash at the 
> >> factory, and custom modes can be loaded on special order.  Other 
> >> switch bits set sync options, such as sync-on-green, composite sync, 
> >> etc.  The DIP switch is accessible on the back panel, without opening 
> >> the case.
> > 
> > We can provide jumpers or a DIP switch (jumpers may be cheaper, but I
> > don't know).  The problem here is identifying a good list of fixed
> > modes that will satisfy everyone.
> > 
> 
> This isn't going to work -- we can't satisfy everyone.  By definition 
> odd ball monitors are not going to be standard.  That is why X11 has 
> modelines.
> 
> We could have it possible for it to start in VESA modes that are larger 
> than 640x480, but that isn't going to help with something odd ball.
> 
> We could have it possible to select some (or all :-() of the standard 
> modelines built into the current XFree86 and X.org releases, but again, 
> there are going to be real odd ball monitors that this isn't going to help.
> 
> I would suggest that a serial NVRAM with the X11 modeline or VESA mode 
> for boot up in it is the best idea.  It might also be a good idea for 
> this to store the VESA modes that were supported.  Since there is a 
> finite list, we would only need a bit for each one (best to have a few 
> to spare since I presume that they may add new ones).  And, it appears 
> the type of sync the monitor needs (H&V, Composite, on Green).
> 
> You could load this NVRAM yourself if you borrowed a VGA monitor or 
> could use your TV.  Otherwise, we could offer the programing service.
> 
> This leaves us with two jumpers (4 choices):
> 
>       VGA
> 
>       TV 480i
> 
>       TV 489p
> 
>       NVRAM stored mode
> 
> and a jumper to enable writing the NVRAM.
> 
> Perhaps we wouldn't need to populate the serial NVRAM on the standard 
> product.
> 
> -- 
> JRT
> 
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