From: Jim Brain on
christianlott1 wrote:
> Is it possible to create a watch/break-point monitor for the 6510 with
> this without implementing the processor inside the FPGA?
One could always implement logic in the FPGA to turn off the data bus
and send a BRK opcode at a certain address.

> 2) RAM -
> Wouldn't you want the fpga to have some ram available?

If it's easy to add, sure. Maybe it could fit on the backside.

> 3) CPU -
> Saved this last because it probably doesn't matter. I see you have a
> serial interface to the fpga. Your design seems to preclude the option
> of hooking in another cpu to the fpga.

No, by all means, implement a dual core CPU in the FPGA.


From: Jim Brain on
BruceMcF wrote:

> But note that attacking the problems a chip at a time does not mean
> that you can never then proceed to put those designs together ...
> indeed, if you stay with the same FPGA family, putting the designs
> together seems like it could be mostly a copy and paste affair.

That would be the idea. Play around with a design (and be able to
isolate and test it against actual peripheral ICs) and then switch to
another design for another IC. Take a design and tweak it, etc.

Then, when people collectively decide there is a VIC-II+ or a SID+ or a
6510+ (with 16 or 32 bit support, or whatever) that satisfies a large
enough set of folks, pull the individual designs into a single FPGA, add
a bit of glue, some IO ports, and ship a new 64 design. (Or a VIC, or a
128, etc.)

Both paths will end up the same place, but the direct path seems to
stall more easily.

From: BruceMcF on
On Apr 13, 5:02 pm, Jim Brain <br...(a)> wrote:
> BruceMcF wrote:
> >> o A new machine that does not emulate at least a 64 in all ways will not
> >> be accepted as a replacement.

> > However, a new portable machine that emulates a 64 with in sufficient
> > ways to run program X will be accepted as a portable way to run
> > program X when not at the C64.

> It will be accepted as such, but that does not seem to be the market.
> The DTV can run many program 'X's, but it has not taken off as a
> solution to the problem at hand.

The DTV is not a social computing device ... you cannot, out of the
box, download a newly patched game, plug something into the DTV, and
run it, nor plug two together and play against someone else.
From: BruceMcF on
On Apr 13, 5:02 pm, Jim Brain <br...(a)> wrote:
> BruceMcF wrote:
> > There's no need to replace the CPU in this approach ... a 65c816 is a
> > stock part, it will do things that are done in standard documented
> > 6510 codes, if program X is one of those programs, it can run on the
> > 65c816, if its able to run a softcore in the FPGA in a box, then
> > implementing an NMOS 6510 with all the unmasked interactive opcodes
> > intact is a project, not a start-up hurdle.

> I think you miss my point by concentrating on the example. Replace CPU
> with VIC-II to understand where I am going. A video tinkerer does not
> want to re-implement the VIC-II, nor does he want to mess around with a
> SID core.

This was not the post where I was going where you were going, but the
one where I was looking at your argument to see where else it led.

But, yeah, someone re-implements the VIC-II and SID to run C64
software. They do it for the chip-board you envision here in order to
be able to *continue* running C64 software *in addition* to new
software that shows off their handiwork. Indeed, they may implement
the VIC-II or SID first so that as they work on their design, the
original VIC-II or SID capabilities are there for regression testing.

However, an FPGA VIC-II and SID have already been implemented. The
design may be behind an IP wall here in the US, but its likely that
the wall is porous in China, which means that for the Democratic
Republic of Congo, that IP wall is not necessarily an insurmountable
From: BruceMcF on
On Apr 13, 5:02 pm, Jim Brain <br...(a)> wrote:
> BruceMcF wrote:
> >> o Few want to recreate something you can buy for $10.00 on eBay. That's
> >> not where the potential excitement lies.

> > You cannot buy a joystick that can go directly onto the internet on
> > eBay for $10. You ought to be able to, but you can't.

> Note I said "recreate", not create. I understand your frustration,
> though, and I think my approach will get us closer in a faster timeframe
> to the $10.00 joystick on the Internet. Or, at least as close as I
> think you will get to that ($10.00 is a pretty low price point for such
> an item. I don't know of any Internet capable devices of any kind that
> sell for $10.00)

Its not frustration, its excitement. Just one four pin cross-link
cable for the C64DTV with an ability to sense and boot from an SD card
when connected into the cable, and the $10 internet capable
joystick ... $20 after distributer margin and profit margin ... would
already exist.