[Info-vax] Decwindows Motif V1.1 kit

[Paul Hardy]

Stephen Hoffman <seaohveh at hoffmanlabs.invalid> wrote:
> On 2019-05-28 21:58:27 +0000, Paul Hardy said:
> 
>> The problem with more recent DECWindows such as CDE is that it 
>> allocates colours at both top and bottom of the hardware colour table,
> 
> I'm going to infer that the code has dependencies on specific 
> documented or possibly on undocumented behaviors of old and buggy 
> DECwindows code, or of the particular graphics hardware involved.

It’s not very unusual for the period when the code was written, and the
limited capabilities of the graphics devices of the time.  It’s allocating
colours in the hardware colour table, such that switching off bits in the
colour lookup table allows the manipulation of visual overlay of two or
more datasets.
> 
> Switch to hardware with more planes, or debug the code.   Also have a 
> look at the previous discussions of DirectColor and TrueColor, and what 
> is supported with your particular graphics controller.

As I said, this is a software archaeology project, trying to archive a
piece of digital mapping history for posterity. As such I’m trying not to
touch the original code, but allow it to be seen in emulation on modern
hardware.

> Old DECwindows has a lot of problems, and you're going to end up 
> chasing those in addition to chasing whatever problems might arise in 
> the particular app code involved here.
> 
The app works fine now when logged on as System, so I could stop there.
However it would be more realistic to be able to run as an unprivileged
user, which was always the case. I’ll continue to investigate as a
background task. 


-- 
Paul at the paulhardy.net domain