[Coco] The 6502 sprints ahead of the 6809: 100Mhz 6502

[Dave Philipsen]

This is an interesting design and nice packaging in the 40-pin DIP. However, in order to run as fast as it does, apparently it copies external ROMs to its internal RAM and then uses that internal RAM exclusively when it runs and then only accesses external stuff for I/O and it slows itself down to do that. So I doubt that it really ‘sprints ahead’ of the 6809 in that regard because we have the 6809 available in FPGA that could likely do the same thing. Likely this device is limited to 64K and would not have the ability to access a larger amount of RAM like the CoCo 3 does (512k, 2M, 8M) without some trade offs. 

So it isn’t exactly a drop-in replacement for a 6502 since it can’t deal with external RAM and it would have to be customized for different environments.  

-Dave Philipsen

> On Oct 13, 2021, at 11:15 AM, John Guin <johnguin at hotmail.com> wrote:
> 
> http://www.e-basteln.de/computing/65f02/65f02/
> 
> This fellow made an FPGA based 6502 running at 100Mhz.  Nifty!
> 
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