16-bit C64/128?
in [Commodore]
|
From: BruceMcF on 13 Apr 2008 10:37 On Apr 13, 12:07 am, Jim Brain <br...(a)jbrain.com> wrote: > I wasn't sure where to hang this idea, given the splintering of the > question into the various factions, so: > Although I'm not sure I grok all of the above points, I think there is > value in developing something that might give users many of these items > at a reasonable cost. > As others have noted, support is the key, but I think everyone has been > so focused on building a new PC, they have ignored other ideas. > Consider: > o A new machine that does not emulate at least a 64 in all ways will not > be accepted as a replacement. > o Emulating a complete 64 is a daunting job. > o Such an all-or-nothing proposition scares enthusiasts away. Some > would be OK tackling replacement CPU, but feel way out of their element > doing video or sound. > o Few want to recreate something you can buy for $10.00 on eBay. That's > not where the potential excitement lies. > Thus, I propose an alternate idea: I think the alternate idea is brilliant ... it does go far beyond the C64 community, and its in a form factor that is ideal for tinkering. Indeed, I'd go so far as to make sure that the board is designed so that it converts from a 40 pin board to a 26 pin board by simply snipping pins. Also, the serial interface a six point SPI header with the boot programming as an SPI device on four of the points. The above points, however, also point to another, parallel, track: > 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. > o Such an all-or-nothing proposition scares enthusiasts away. Some > would be OK tackling replacement CPU, but feel way out of their element > doing video or sound. 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. > 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 $10. You ought to be able to, but you can't.
From: Brian Ketterling on 13 Apr 2008 11:58 In news:uGfMj.64534$TT4.15208(a)attbi_s22, Jim Brain <brain(a)jbrain.com> wrote: > A regular user can buy and install a few of these boards under existing > ICs like SID, VIC, CPU, CIA, etc. Nothing special occurs. > > However, interested developers can than target these boards to develop > new VIC cores, new SID stuff, etc... I like it, a lot. As a member of the peanut gallery, it's what I've been hoping for for years! Brian --
From: christianlott1 on 13 Apr 2008 13:22 > Jim Brain <br...(a)jbrain.com> wrote: This is really a perfect idea. Wakerly's Digital Design book has been calling me :) Because I like this idea so much, I have three concerns: 1) Debug/Pass-thru/Supplementing - Is it possible to create a watch/break-point monitor for the 6510 with this without implementing the processor inside the FPGA? 2) RAM - Wouldn't you want the fpga to have some ram available? 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. some old ideas you may recall: http://70.116.30.93:6809/ex_boards.png Christian
From: BruceMcF on 13 Apr 2008 14:50 On Apr 13, 1:22 pm, christianlott1 <christianlo...(a)yahoo.com> wrote: > > Jim Brain <br...(a)jbrain.com> wrote: > This is really a perfect idea. Wakerly's Digital Design book has been > calling me :) > Because I like this idea so much, I have three concerns: > 1) Debug/Pass-thru/Supplementing - > Is it possible to create a watch/break-point monitor for the 6510 with > this without implementing the processor inside the FPGA? If I understand the idea correctly, you could have a watch/break point monitor for the 6510 the old fashioned way ... put a 6510 socket in a watch / break point monitor and run wires (eg, four wire ribbon cable) to the device that wants the service. 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. > 2) RAM - > Wouldn't you want the fpga to have some ram available? That's just a matter of selecting an appropriate FPGA ... most families have ram blocks in addition to logic cell blocks. > 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. If I understand it, each FPGA in this particular approach is going into an actual socket in an actual C64 (or C128). Once the design is publicly available, though, then the *design* becomes a soft core, and can be combined with other soft cores in an FPGA. So this *hardware* would hook up to another FPGA the old fashioned way, like a chip on a board, but the *design* can be combined with other *designs* in a single FPGA.
From: Jim Brain on 13 Apr 2008 17:02
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. > >> o Such an all-or-nothing proposition scares enthusiasts away. Some >> would be OK tackling replacement CPU, but feel way out of their element >> doing video or sound. > > 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. > >> 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) Jim |