X11 expertise on ancient HW sought... (4-plane visual (overlay) via X-server on MS-WIndows)

[Peter Coghlan]

Richard Loken wrote:
>
> On Thu, 4 Jun 2015, IMAP List Administration wrote:
>
> > On the original hardware, xdpyinfo tells me:
> > > [...]
> > > supported pixmap formats:
> > >     [...]
> > >     depth 4, bits_per_pixel 8, scanline_pad 32
> > >     [...]
> > > screen #0:
> > >    [...]
> > >   depths (4):    8, 12, 24, 4
>
> I can muddy the water for you.  On my VMS 8.3 box (a not new Alphastation
> 500) I get this:
>
>     richardlo $ xdpyinfo
>     name of display:    _WSA2:
>     version number:    11.0
>     vendor string:    DECWINDOWS Hewlett-Packard Development Company OpenVMS
>     vendor release number:    8003
>     maximum request size:  65535 longwords (262140 bytes)
>     motion buffer size:  0
>     bitmap unit, bit order, padding:    32, LSBFirst, 32
>     image byte order:    LSBFirst
>     number of supported pixmap formats:    2
>     supported pixmap formats:
>         depth 1, bits_per_pixel 1, scanline_pad 32
>         depth 8, bits_per_pixel 8, scanline_pad 32
>
> So I don't have a pixmap format with a depth of 4 either.  But my Redhat
> Linux EL6.6 box does, it reports support for 1, 4, 8, 15, 16, 24, and 32.
>

If further muddying is required, my about 20 year old Alphaserver 800 running
VMS 8.2 with a Powerstorm something (maybe 3D30 or 4D20?) graphics card and my
PWS 500a(u) running VMS 8.3 and some slightly lesser capable graphics card that
I cannot recall the name of at all both report this:

  visual:
    visual id:    0x36
    class:    PseudoColor
    depth:    4 planes
    size of colormap:    16 entries
    red, green, blue masks:    0x0, 0x0, 0x0
    significant bits in color specification:    4 bits

and this:

SERVER_OVERLAY_VISUALS(SERVER_OVERLAY_VISUALS) = 0x36, 0x1, 0x0, 0x1

Regards,
Peter Coghlan.