Hi Ruud, On Tue, Mar 06, 2012 at 05:13:45PM +0100, Ruud@Baltissen.org wrote: > Hallo Gábor, > > > > I'm thinking on starting to do some hw development. .... > > .... > > First of all, since I don't have too much experience, what do > > you think, is it such a simple task, or am I wrong? > > With all respect, but you didn't state very clearly what you want to > do with this uC. You are talking about "transfer rate"; between the > C64 and uC or between the uC and the outside world? The connection Surely the transfer rate between C64 and the uC this time only. As far as I can see: LDA $DD01 STA BUFFER LDA $DD01 STA BUFFER+1 [...] With this "unrolled-loop" the maximal transfer rate can be told, for sure, in a more realistic example some would use some kind of loop anyway. This was for reading, something similar for the opposite direction. And as far as I can understand the things, CIA can provide a (with "PC") for the uC that new data put on (on C64 write), or data is read (so next can be placed for read by the C64). > could be as simple as using the existing RS-232, not slow, but less > effort needed to program things. > > > > I prefer user port, because it exists on other machines as well, > > But they are not all the same! And you need a program to run the > whole thing. Using the expansion connector you can include the > program on an EPROM. I know that they are not the same, but at least as far as I can see, there is common ground; 8 bit data, programmable input/output, and at least on C64 hardware level handshaking, so I can know if new data is read/written by the CPU (well of course with the expansion connector it's even more trivial as I can tell when there is R/W for the I/O area, etc). However the major point, that DTV does not have an expansion port/connector at all, but it has user port (though afaik there is no "PC" handshaking line there). What I would like to build some stupid prototype board, which can be connected to at least DTV and C64 too (I am not sure about the Plus/4 though). Honestly, I am not an uC-expert at all, but I have friend who is. However he told me that he is not so much interested about the CBM part, so he can help if I figure out the "commodore side" of the story. After all, my hope that I can learn something new from this try at least ... The reason I'd like decent transfer rate between C64 (or DTV) and the uC: I'd like to use an uC with ethernet capabilities later. Though there are ethernet solutions (like TFE or RR-Net) for the C64, I always felt that I want something like this for DTV too, where there is no solution for the problem (and you don't have an std C64 bus at all - but you have some kind of user port at least, even if it's not the very same). As DTV has many memory, and I already experimented with some kind of "advanced OS" (multitasking etc) for the DTV, it would be really nice to have TCP/IP too (I've already have a partly working stuff like that for RR-Net on C64, as uIP seems to be complicated for me - and it's C - and I haven't heard too much about IP65 when I started that project). But currently I want to focus only a solution which provides good transfer rate between C64 and a uC without thinking other topics. - Gábor Message was sent through the cbm-hackers mailing listReceived on 2012-03-06 17:00:49
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