🚀 go-pugleaf

wine@maui.cs.ucla.edu writes:

> We'd like to use our 5081 as a display device for images using Xwindows,
> but we can only get 16 levels of grey out of it.  Is there any way
> to get 256 levels of grey (hardware, and/or software)? 

I had the same problem, but IBM-Denmark got hold of a new version of
the Color Palette chip for the Megapel Adapter cards. The new version
have a 3 x 8 bit entry (instead of 3 x 4) for each color to lookup,
giving 256 greylevels at your Megapel (and is faster?). As far as I
understand only X11 (AIX/RT X-Windows V2.1) running under AIX 2.2.1,
knows how to make use of all the 24 bits in the Color Palette.  I got
hold of some test programs (from IBM) which left no doubt that the
upgrade worked. I haven't yet tried it with X11, while I am waiting
(and waiting (and waiting...)) for NFS, before I will upgrade to
AIX2.2.1 and AIX/RT X-Windows V2.1.

Below a short description of the hardware upgrade, as I made it:

Prev : Bt451KG100 
       RAMDAC
       <serial no>

New  : Bt458KG125 
       RAMDAC
       <serial no>

Location: At the Megapel-controller card (the bottom one of the two
cards of the Megapel adapter) near the outlet for the RGB-signals,
grey, 3 cm square, (~ 1.25"). NOTE the writing at the chip is upside
down (if you have the RGB-outlet to your right).

Replace the chip and make sure the writing turns out upside down.
Note that it does *NOT* sit directly on the socket, there is a small
(~ 1 mm.) space of air between them.

Have fun, but be aware: the cards/chips are STATIC SENSITIVE DEVICES!
--
dearwolf@diku.dk                             Mikael C. Kjaerulff 
Department of Computer Science, University of Copenhagen, Denmark