It appears that I have made something of a gaff!
My Information Elves (you know them -- they're the "i.e." in
foo (i.e., bar)) now inform me that the chip rev that includes the
EXTRA_HALFBRITE display mode discussed in my earlier message is
not yet in the production line for Amiga computers. The chip in
question is the custom chip numbered 8362. It is the large chip
closest to and running parallel to the power supply. The current
Amiga production runs include revision number 5 of that chip
(8362R5). EXTRA_HALFBRITE first makes its appearance in R6.
[For those of you who like to get anthropomorphic, the 8362 is
also known as Daphne or Denise depending upon just how long you've
What this all means is that EXTRA_HALFBRITE mode is not available in
consumer Amigas at this point. I can guarantee that Amigas produced
after Q1 1986 will have the necessary chip rev -- possibly sooner.
Apparently what confused the I.E.'s is that a batch of Amigas was
made with R6's to insure that we hadn't busted something. We hadn't.
Thus the little guys made the assumption that production was going
to continue with R6's.
It is to blush.
Meanwhile, my statement that consumer machines handle HAM displays
correctly is true. This function is also handled in the 8362 and
works fine in R5. Some R5's were not, however, tested for this
function back when we were making pre-release machines for developers
and are not running fast enough to do HAM properly. All consumer
machines HAVE BEEN properly tested for HAM function along with the
rest of the battery of tests and burn-in procedures done as a matter
of course on the Amiga assembly line.
I apologize for any confusion this has caused. The I.E.'s would
apologize too except, right now, they're hiding under the sofa.
There have been some carpings about commercial presences on the net.
I'd be very, very happy to see more companies making themselves
available for comment and questioning. Amiga's net participation
has been the soul of propriety, a far cry from commercialization.
gould/csd - urbana