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Groups > comp.sys.acorn.programmer > #6264

Re: White background colour in GCOL is grey.

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In article <bf20a335-0a73-4649-a195-b8a69bc329f2n@googlegroups.com>,
   George Pearce <chasgpearce@gmail.com> wrote:
> On Wednesday, 12 May 2021 at 18:35:03 UTC+1, Steve Fryatt wrote:
> > On 12 May, Richard Ashbery wrote in message 
> > <592b7c18...@invalid.addr.uk>:
> > > In article <912abee8-d3e2-482b...@googlegroups.com>, 
> > > George Pearce <chasg...@gmail.com> wrote: 
> > 
> > > > I am simply trying to open a graphics window with a white
> > > > background in 16 million colour mode in RIScOS 4.?. I am
> > > > calling MODE MODE in 1900x1080p. GCOL seems to have been
> > > > extended in v5. 
> > > 
> > > > Best I can do is GCOL 0, 191, which seem to give a light grey
> > > > rather than full white. I can obviously correct this after
> > > > the event, but am sure there must be a solution which I have
> > > > yet to discover. 
> > > 
> > > GCOL ON 255,255,255 : CLG
> > That's RISC OS 5 only, so doesn't meet the OP's requirement of
> > RISC OS 4 unless soft-loading BASIC is up for consideration. 
> > 
> > GCOL 0, 255, 255, 255 : CLG might do what's required, though. 

> No, that does not work, screen colour is still black. 

> It seems to me there is an issue with COL, GCOL in 16 million mode,
> with no distinction between foreground and background colours, and
> no palette as such. In 16 and 256 colour modes ,  colours  up to
> 128 are foreground, and above that are background.

> I'm now very confused. I think the BASIC manual needs updating to
> deal with the larger monitor resolutions we now mostly have, and
> the entries for COL and GCOL need to address 16million mode.

> I understand their application in 16 and 256 colour modes, though I
> do find the manual a bit confusing.

You do not say what version of RISC OS you are using, or which version
of BASIC, or what hardware you are running on. Any of those may be
your problem - the BASIC manual has been updated, but largely to
reflect changes made in the many years since RO4. 

If the problem is the version of BASIC, then the most recent version
can be soft-loaded, as Steve said above.

-- 
Martin Avison 
Note that unfortunately this email address will become invalid
without notice if (when) any spam is received. 

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White background colour in GCOL is grey. George Pearce <chasgpearce@gmail.com> - 2021-05-11 07:03 -0700
  Re: White background colour in GCOL is grey. Richard Coleman <coleman@orpheusmail.co.uk> - 2021-05-12 06:44 -0700
  Re: White background colour in GCOL is grey. Richard Ashbery <basura@invalid.addr.uk> - 2021-05-12 14:53 +0100
    Re: White background colour in GCOL is grey. Steve Fryatt <news@stevefryatt.org.uk> - 2021-05-12 18:23 +0100
      Re: White background colour in GCOL is grey. George Pearce <chasgpearce@gmail.com> - 2021-05-13 02:38 -0700
        Re: White background colour in GCOL is grey. Martin <News03@avisoft.f9.co.uk> - 2021-05-13 12:33 +0100
          Re: White background colour in GCOL is grey. George Pearce <chasgpearce@gmail.com> - 2021-05-13 06:40 -0700
            Re: White background colour in GCOL is grey. News <chrisjohnson@spamcop.net> - 2021-05-13 16:49 +0100
            Re: White background colour in GCOL is grey. Martin <News03@avisoft.f9.co.uk> - 2021-05-13 17:09 +0100
              Re: White background colour in GCOL is grey. George Pearce <chasgpearce@gmail.com> - 2021-05-13 09:22 -0700
        Re: White background colour in GCOL is grey. J Peachey <john@jpeachey.co.uk> - 2021-05-13 15:04 +0100
        Re: White background colour in GCOL is grey. Steve Fryatt <news@stevefryatt.org.uk> - 2021-05-13 21:52 +0100
          Re: White background colour in GCOL is grey. George Pearce <chasgpearce@gmail.com> - 2021-05-14 02:54 -0700
            Re: White background colour in GCOL is grey. Martin <News03@avisoft.f9.co.uk> - 2021-05-14 11:05 +0100
              Re: White background colour in GCOL is grey. George Pearce <chasgpearce@gmail.com> - 2021-05-14 07:50 -0700

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