Hi, I am having a hard time deciding where to plug this thing in. I actually started the project AS a super C64 on a chip or two. Mostly my design has been around VIC compatible registers on a much faster buss. If I hack this into a C64 then I'm stuck with that configuration(memory map) in the S-C64. Any help people can give with the original VIC internals will be very helpfull. Jeri ----- Original Message ----- From: Richard Atkinson <rga24@hermes.cam.ac.uk> To: <cbm-hackers@dot.tml.hut.fi> Sent: Tuesday, September 26, 2000 8:43 PM Subject: Re: VHDL > Jeri, > > Very interesting project. I and several others talked about VIC-II > reverse-engineering projects for several months and it comes up quite > frequently on csc in the form of the "someone should do a c64 on a chip" > thread. However, it was only in the past few weeks that I actually started > on my VIC-II in Verilog project in earnest. My new job at > www.tenisontech.com had something to do with it... It's not really got to > anything like the stage yours has, of course. > > Anyway, I'm interested in adding VIC-II compatibility to your design, but > some fundamental decisions have to be made. Originally I proposed an FPGA > with some pins that were plug-in replacements for the real VIC, but made > no attempt to provide an analogue interface (of course). Instead, a 4 bit > (or possibly 8 bit) digital output for the colour numbers at the current > pixel (the extra 4 bits being for the line above which is relevant in a > PAL emulation) was the plan. Then I thought about integrating a "RAMDAC" > too, with some method of changing the default colour allocations in case > the user didn't like them. > > What's your ultimate aim for your video chip project? Will it be a plug-in > replacement for the VIC-II or a hybrid similar to mine or a second display > like the one in the SID socket at the Expo? Leaving aside C64-on-a-chip > concerns for now, I think the VIC-II is the first hurdle. PAL/NTSC and > revision selection are easy enough to implement, hence I included them in > my original spec. What I left open (although thinking about them for a > while) were enhancements to the VIC-II; particularly a second memory > interface for high speed video accesses (hires video modes etc) and the > precise details of how the analogue video interface would work. I > certainly had connection to an RGB 15kHz television-style monitor in mind, > though. VGA was not in my original plan. > > > Richard. > > - > This message was sent through the cbm-hackers mailing list. > To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi. > - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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