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GARTHWILSON
PostPosted: Mon May 01, 2017 7:04 am 
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https://www.youtube.com/watch?v=TJ9RllBv1pg

50 or 60fps, 256-color video streaming on a 1.79MHz 6502 Atari (not emulated), with data coming from a CompactFlash card

I don't know anything about it other than what is said there; but it sure is impressive!

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BigEd
PostPosted: Mon May 01, 2017 7:52 am 
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There's a relevant thread or two on AtariAge. This one has some technical details: the ANTIC is using DMA to pull data direct from the IDE interface in the CF cartridge.
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The register flips and the audio are all driven by a full-screen kernel, which issues a 12 byte sector read to the IDE device per frame. ANTIC DMAs in 5824 bytes of video over 182 narrow width scanlines, and then the CPU reads in another 320 bytes containing 262 bytes of sound data over 32 more scanlines. The IDE device has the remaining 3ms to prepare for the next read command. Source is attached
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cbmeeks
PostPosted: Mon May 01, 2017 1:09 pm 
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Can you imagine how many more Atari's would have been sold if we had the cheap CF devices back then?

I've seen something similar on the C64 with REU and 16 MB of RAM or so.

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Aslak3
PostPosted: Tue May 02, 2017 7:09 pm 
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It's impressive, but really it is one huge tradeoff of disk space vs CPU time. Plus of course the DMAC is needed to get the images into video memory fast enough. It's equivalent to putting a super efficient modern petrol engine in a Model T.

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Mike Naberezny
PostPosted: Fri May 12, 2017 7:08 pm 
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cbmeeks wrote:
I've seen something similar on the C64 with REU and 16 MB of RAM or so.

They're called "Nuvies" (see the YouTube videos).

Commodore produced RAM Expansion Units (REUs) for the C64/128 that came in capacities of 128-512K. They use the MOS 8726 controller chip, which can do fast DMA transfers between the expansion RAM and the system's main memory. The original Commodore REUs used 41256 DRAMs, and there was a popular hardware hack to add more 41256s for up to 2MB. Nuvies run on modern devices like the 1541 Ultimate devices, which include an emulation of the 8726 and the full 16MB RAM.

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