Vaxstation 4000 m60 and NetBSD

[Maciej W. Rozycki]

On Tue, 19 Dec 2017, Charles Dickman via cctalk wrote:

> > Hardware support say no support for LCG Graphics :-(
> 
> There are a few people willing to work on graphics for old
> vaxstations, but there is no documentation.
> 
> If anyone has documentation, the netbsd vax port mailing list would be
> very interested.

 The RAMDAC is standard, so as long as frame buffer memory is mapped into 
the CDAL address space writing a dumb device driver should be pretty 
straightforward with little reverse engineering effort.  And CDAL address 
decoding is I believe documented in the KA46 board specification.

 And all else failing you can always resort to TURBOchannel graphics wired 
via a TURBOchannel adapter.  While not supported by the console monitor, 
it can be handled by the OS just fine, and several TURBOchannel graphics 
drivers are already available for other ports, so it's just a matter of a 
suitable kernel configuration (with minor patching possibly, depending on 
how cleanly written the respective drivers are).

 I was able to get OS console output using at least the HX and one of the 
HX+ options with my m90 and the (still very crippled and long neglected) 
VAX/Linux port several years ago.  The MX, CX and TX options should be 
easily supportable too.  Only accelerators (PixelStamp and PixelVision 
architecture implementations) might cause trouble for one reason or 
another (such as using DMA or requiring a TURBOchannel extender, which are 
scarcer than hen's teeth).

 FWIW,

  Maciej