QBZJ@CORNELLA.BITNET (07/17/86)
The blitter will supposedly come with new ROMs. I suspect that there
will be more than just the blitter chip and the socket for the 68000 on
the blitter board. By the way, this thing is also expected to provide
half-toning which I had always thought was bordering white lines with grey.
The idea behind this is that your eye sees less contrast between any element
of the line and the surrounding background and bloops over the jaggles on
diiagonal lines. The result is the illusion of a perfect line. My point is
that if this is to work on monochrome systems then some modification of the
viideo circuitry is necessary to get grey as well as black and white. Perhaps
the half-toning will only be supported on the color systems. Or it will
require a little bit more than sticking it in the 68000 socket to make it go.
I guess we just need more technical informationn on the blitter's projected
capabilities and installation scheme. But there appears to be good grounds
for remaining optimistic about installing one in the 520st. Could any
one at ATARI (neil?) please shed some light on any ofthese points?
peter lorraine
qbzj@cornella.bitnetbammi@cwruecmp.UUCP (Jwahar R. Bammi) (07/18/86)
> The blitter will supposedly come with new ROMs. I suspect that there > will be more than just the blitter chip and the socket for the 68000 on > the blitter board. By the way, this thing is also expected to provide > half-toning which I had always thought was bordering white lines with grey. > The idea behind this is that your eye sees less contrast between any element > of the line and the surrounding background and bloops over the jaggles on > diiagonal lines. The result is the illusion of a perfect line. My point is > that if this is to work on monochrome systems then some modification of the > viideo circuitry is necessary to get grey as well as black and > white. Perhaps the half-toning will only be supported on the color > systems. Or it will require a little bit more than sticking it in > the 68000 socket to make it go. What you describe above is known as Antialiasing. In half toning a group of pixels - normally a square group like 4x4 - behaves like one pixel, and depending upon how many of the pixels are on you get illusions of different shades of gray or even patterns. Of course you loose out on resolution, but it is useful for filling type operations. Can someone at Atari tell us if the blitter will support gray levels too? Landon or Neil perhaps. -- Jwahar R. Bammi Usenet: .....!decvax!cwruecmp!bammi CSnet: bammi@case Arpa: bammi%case@csnet-relay CompuServe: 71515,155