Deja News Toolbar Get some help to grow your business Get some help to grow your business message/thread Message 12 of 93 for search * return to search results help Re: New Idea!! SuperDMA64 Author: waggtail Date: 1999/02/27 Forum: comp.sys.cbm sponsored by: eBay more headers author posting history post reply prev next _________________________________________________________________ I NEED HELP.... MY LOGIC IS IF VIC CAN GET ITS INFORMATION FROM RAM AT 8MHz THEN WHY NOT A CART. IN THE EXPANCION PORT STORING INFO AT 8MHz USING DMA???? ITS MY IDEA TO CRREATE A VIDEO CAPTURE CARD FOR THE C=128/C=64 THAT ENABLES THE COMPUTER TO CAPURE A VIDEO CLIP TO RAMLINK ....... USERS WILL NEED AT LEAST 1MEG OF RLINK RAM...... I NEED HELP.... PEAPLE WHO ARE UNDERSTANDING THE C=64/C=128 ARCATECTURE BETTER THEN ME.... EVEN THOSE WHY HAVE A DEEPER UNDERSTANDING OF NTSC..... MY FIST VERSION IS GOING TO BE NOTHING MORE THEN 160/160 GREYSCALE (4 LEVEL) NO SOUND CLIP..... AND I PLAN TO DISTRIBUT A FREE PLAYER..... I NEED HELP... LIKE THIS: IS DMA ABLE TO HANDLE 8MHz ...? EMAIL ME : c128user@geocities.com and I'll share my ideas wiht you... lets get to gether ... im not doing this for the money.... just the credit....a nice cut of the profets..../and i want to see this puppy in action asap ASAP A S A P !!!!!!!!! In article <7l90dos121.fsf@siphon.hut.fi>, Marko =?ISO-8859-1?Q?M=E4kel=E4?= wrote: > >>>>> "John/Lori" == John/Lori writes: > > John/Lori> I'm not sure I understand. I can't remember if the 6510 > John/Lori> tristates it's bus during phi 2(?) > > It tristates its bus when you tell it to do so with the AEC (Address > Enable Clock) signal. > > John/Lori> if not, you'll have to use /DMA. Is there some good reason > John/Lori> not to? > > When pulled low, the -DMA input on the cartridge port will affect AEC > and RDY on the processor. These signals are normally generated by the > video chip. Using the BA output on the cartridge port, the video chip > will be able to tell an external device when it needs the bus. That's > how e.g. the REU will know to pause the transfer during bad lines. > > John/Lori> You want to run the bus at twice the normal clock speed > John/Lori> during BA and normally the rest of the time? > > Such a modification was actually presented in the 64'er magazine some > years ago. I think it was issue 2/1994 or 3/1994. It was all but a > trivial modification. The processor was replaced with a 65C02, and a > circuit had to be added to emulate the on-chip I/O register to some > extent. It could also have been that the circuit had to be tuned for > the particular machine, since the timings were really tight. > > The fact that the video chip and the processor are clocked from the > same source makes it possible to write really amazing raster effects, > but it also severely limits the possibilities on the hardware side. > I'd eat my hat if someone boosts the bus speed of the C64 to, say, > 8 MB/s. External turbo cards (which disable the internal processor) > have a cache on the card; the bus speed remains the same. > > Marko > -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own _________________________________________________________________ view for bookmarking text only mail this message to a friend post reply << prev · next >> subscribe to comp.sys.cbm SPONSORED LINKS Yellow Pages · Great Deals at uBid! · Shopping · Free Stuff · 5¢ long distance AutoConnect · Trade with Datek · Auctions & Classifieds · GET IT NOW @ NECX Home · Communities · My Deja News · Power Search · Post About Deja News · Ad Info · Our Advertisers ____________________________________________________ Copyright © 1995-99 Deja News, Inc. All rights reserved. Conditions of use · Site privacy statement reviewed by TRUSTe