Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!swrinde!emory!mephisto!mcnc!thorin!hatteras!mueller From: mueller@hatteras.cs.unc.edu (Carl Mueller) Newsgroups: comp.sys.amiga Subject: Re: Bank switched CHIP RAM? (Re: 24 Bit Video ..) Keywords: Off the wall idea? Message-ID: <16536@thorin.cs.unc.edu> Date: 4 Oct 90 17:09:11 GMT References: <1990Sep21.184056.14 <27024b15-2c05.11comp.sys.amiga-1@tronsbox.xei.com> <1990Sep28.022138.19237@zip.eecs.umich.edu> <1990Sep30.233751.3244@zorch.SF-Bay.ORG> <1990Oct3.194556.7031@lth.se> Sender: news@thorin.cs.unc.edu Reply-To: mueller@hatteras.cs.unc.edu (Carl Mueller) Organization: University Of North Carolina, Chapel Hill Lines: 68 In article <1990Oct3.194556.7031@lth.se> d87sg@efd.lth.se (Svante Gellerstam) writes: >In article <1990Sep30.233751.3244@zorch.SF-Bay.ORG> xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) writes: >> < lots of inspiering ideas on bank switched CHIPRAM deleted :-> > >Ok, this is a way to get more bits per EACH color. [...] >Even on a 25MHz '030 a measly (professionally speaking) 640 x 400 >screen becomes zippy as old chewinggum. Remember, it's still the slow graphics chips doing a lot of the work here, not the '030. >The big step would be to break away from the current CHIP-mem + >generic chipset architecture (not replace, just add to, that is). Anything done to increase the capabilities must definitely be an extension of some sort, to maintain compatibility. > The really hairy problem of getting a hires display (say 1280 x 1024 x >8 plus) is mainly getting the bits onto the screen and then give the >CPU or graphics coprocessor time to do its stuff. [...] >One hardware event that would make the bank switching idea >semi-interestring is an async chipset running at lots of nice little >MHz's. Then they would be able to more fully use an area of high speed >video RAM. But that would also mean that every special graphics >adapter would have to be specially designed for the Amiga. This >implies high R&D costs and a high end price. Whoa! You don't need all that. That's what video RAMs were designed to get around: they have two access ports. The CPU (or whatever) can access that V-RAM on the main port as usual. The V-RAM has a second serial access read-port which the display refresh hardware would use to update the screen. The two ports can be active at the same time. Integrating these devices into the Amiga would still require a lot of custom design. At this point, nobody should expect a color megapixel display to come cheap. But I'm sure we'd all like to see SOMETHING available soon, even if it cost as much as a Mac-type video adapter. It's also definitely agreed that there will have to be a defined standard for the OS to use an add-on display. This I'm sure will be a subject for a lot of heated debate. Some features of the current chip-set just might not be available in all add-on boards, such as pull-down screens with different display modes. This is an area where I'm hoping things will start happening NOW! Currently, the Mac seems to be the only computer where this is handled well (i.e. OS & programs working well with different display adapters). Have you ever worked on a Mac with a color and a black and white display attached and noticed how you can smoothly drag a window from one to the other? True, it's a simple thing, and some people will have no use for it, but many people WILL! In summary, the OS support should be developed ASAP, and then the hardware can follow. Remember, I'm talking about add-on hardware, not necessarily included with a future Amiga. That way, people who don't need it won't have to shell out the $$. Well, I think I've rambled enough for now! >All ideas has some use :-) >>Kent, the man from xanth. >> > 2:200/107.4 Svante Gellerstam (Fido) d87sg@efd.lth.se (InterNet) -Carl Mueller (mueller@cs.unc.edu)