Jared Smolens wrote:

> 
> Dear mailinglist,
> 
> I recently came across a DECstation 5000/260 with a PMAGB-B framebuffer.
>  Since this machine is a whole lot faster than my 3100, I'd like to
> upgrade. It seems as if there's a problem syncing with my monitor.  When
> doing the framebuffer tests, everything is extrememly squiggly and when
> the boot prompt comes up, it's spread all over the screen, of course. 
> The monitor is a DEC VR 160-DA, something like 14 or 15" screen and it
> works fine with the 3100.  

The problem here is that the 3100 does 1024x864 and the PMAGB-B does
1280x1024.

> My question - is there a way to change the frequency of the framebuffer
> to sync with the monitor (either by jumpers or by typing something at
> the boot prompt?) or do I have to scavange around for a new monitor? 
> There's an Out=osc0 jumper, a PROM=secure jumper and two "spare jumper"
> positions on the framebuffer.  I have tried various permutations of
> these settings and nothing seems to help.  

To use the same monitor on the 5000/260, you'll need either a PMAG-B or
a crystal to put in the spare socket of the PMAGB-B to drive it at the
lower resolution (the the Out=osc0 jumper will do something useful).
The crystal you need is a 69.1968MHz one.

I'm not 100% sure if Xpmax (the X server) supports a PMAGB-B running at
the lower resolution - anyone?

Simon.