x16 processor compared? Youtube videos found

[iljitsch]

If you need more speed, the first step would be to simply run the 65C02 at its maximum clock rate of 14 MHz...

And with only 4000 transistors, I'm sure the 6502 can be implemented at significantly higher speeds on an FPGA.

But at what point is the thing so fast that it's no longer an 8-bit computer (or even a 16-bit one) as we know them? Now you can start doing things that would never fly with a computer from the 1980s or 1990s because you have so many cycles to burn.

[BruceMcF]

5 hours ago, Travis Bryant moore said:

That was interesting. But I wonder if scaling is a factor in over all systems take the C64 DTV where you have everything in an all in one chip that is many times smaller compared to the C64 bread box or even the C64 ultimate elite. Is it faster or better to miniaturize the entire machine or emulate it in an fpga or ASIC? I just think that when you have everything closer together you save time and energy in smaller form factors. And I think I heard 8 bit guy mention the Asic route if it sells good for the cx 16.

The mostly FPGA route is to make a system that is compatible with the real CX16. The real board with real chips is the system reference design. There are already plenty of projects that run fast 32bit hardware on inexpensive boards, there's no particular reason to make another one of this.

Remember that the origin of the whole idea was people asking David for advice on what old system to buy to get the "eight bit experience" and David realizing he couldn't really recommend one as a good starter system. "ASIC" here doesn't mean custom ASIC, it means off the shelf ASIC as much as possible, ideally through pin chips, which is the CX16p system reference platform. That necessarily costs hundredS of dollars. Then the cost reduced CX16c is mostly ASIC, but surface mount where available for lower assembly cost, maybe a single surface mount SRAM, maybe the address / chip select logic with a CPLD rather than all that glue logic. Maybe still hundredS, but lower cost. Then the mostly FPGA version would not be primarily about making it run fast, but about getting the board cost under $100, if possible.

 

[rje]

2 hours ago, iljitsch said:

If you need more speed, the first step would be to simply run the 65C02 at its maximum clock rate of 14 MHz...



And with only 4000 transistors, I'm sure the 6502 can be implemented at significantly higher speeds on an FPGA.



But at what point is the thing so fast that it's no longer an 8-bit computer (or even a 16-bit one) as we know them? Now you can start doing things that would never fly with a computer from the 1980s or 1990s because you have so many cycles to burn.

Bruce's post helps understand the context:

1 hour ago, BruceMcF said:

Remember that the origin of the whole idea was people asking David for advice on what old system to buy to get the "eight bit experience" and David realizing he couldn't really recommend one as a good starter system. 

Now note that the X16 interacts with components whose two main criteria are (a) price point and (b) COTS for an 8-bit system.

In short, 14 mhz appears to be beyond the requirements and capability of the system.  And that includes performance characteristics of the system's various affordable components.

When the goal is Affordably make an interesting 6502-based system then performance is not the primary purpose.

 

Just with mostly off-the-shelf parts, the X16 surpasses the Commodore 65 prototype.  That's as good a goal as you need.

 

[Travis Bryant moore]

Thankyou everyone for your replies. I hope it all works out. but in over all systems I am sure the sd card is a big bonus as it gives it an advantage greater than dvd to blue ray capacity? I mean could you imagine a Commodore CD or Amiga DVD system? I mean just think if you had three pins to page read and write data from an SD card like the new m.2 solid state hard drive and ram hybrid being done on computers today?

[TomXP411]

On 6/3/2021 at 6:03 AM, iljitsch said:

If you need more speed, the first step would be to simply run the 65C02 at its maximum clock rate of 14 MHz...



And with only 4000 transistors, I'm sure the 6502 can be implemented at significantly higher speeds on an FPGA.

So far, the fastest implementation is 48MHz, as seen on the Ultimate 64. 

 

all the U64 needs is an 80 column mode now...

[BruceMcF]

12 hours ago, TomXP411 said:

So far, the fastest implementation is 48MHz, as seen on the Ultimate 64. 

 



all the U64 needs is an 80 column mode now...

Coincidentally, AFAIR the top clock speed of the ez80, which can be put into z80 instruction mode, is 50MHz. But it would invert the relationship between 65xx and z80 clock speeds and processing performance, since the ez80 versions of the instructions are mostly single cycle per memory access.

[paulscottrobson]

On 6/3/2021 at 2:03 PM, iljitsch said:

If you need more speed, the first step would be to simply run the 65C02 at its maximum clock rate of 14 MHz...



And with only 4000 transistors, I'm sure the 6502 can be implemented at significantly higher speeds on an FPGA.



But at what point is the thing so fast that it's no longer an 8-bit computer (or even a 16-bit one) as we know them? Now you can start doing things that would never fly with a computer from the 1980s or 1990s because you have so many cycles to burn.

Because you could develop in things other than assembler without crashing into memory problems or VM performance issues. Most of the speed gain is lost because the system is full of 16 bit data.