In the beginning was the MOS6502, an 8-bit microprocessor that found its way into many famous machines. Some of you will know that a CMOS 6502 was created by the Western Design Center, and in turn, WDC produced the 65C816, a 16-bit version that was used in the Apple IIgs as well as the Super Nintendo. It was news to us that they had a 32-bit version in their sights, but after producing a datasheet, they never brought it to market. Last October, [Mike Kohn] produced a Verilog version of this W65C832 processor, so it can be experienced via an FPGA.
The description dives into the differences between the 32, 16, and 8-bit variants of the 6502, and we can see some of the same hurdles that must have faced designers of other chips in that era as they moved their architectures with the times while maintaining backwards compatibility. From our (admittedly basic) understanding it appears to retain that 6502 simplicity in the way that Intel architectures did not, so it’s tempting to imagine what future might have happened had this chip made it to market. We’re guessing that you would still be reading through an Intel or ARM, but perhaps we might have seen a different path taken by 1990s game consoles.
If you’d like to dive deeper into 6502 history, the chip recently turned 50.
Thanks [Liam Proven] for the tip.
That’s cool. Hopefully it finds it way into real hardware eventually (say, an ASIC).
It would be nice for making a more modern SuperCPU for the C64, for example.
https://en.wikipedia.org/wiki/SuperCPU
I am imagining what a C64 386 equivalent would look like.
With C64’s BASIC and GEOS adapted to run on this W65C832 as a start.
A computer without software has not earned its right to live. It’s a nice idea to have such a CPU. But why? There is no software at all, because the CPU never existed.
Of course you could see it as an accelerator for an old 6502 system… But come on, you don’t need a 32 bit CPU for that. All you need is a hugely fast 8-bit 6502. And they exist already.
Much easier, cheaper and more feasible would be a Raspberry PI with a 6502 emulator. Like a PiStorm is for 68000, surely someone could make a PiStorm for 6502, right?
TBH, I did a quick search, but there doesn’t seem to be a PiStorm for 6502.
The Apple IIGS could use it. Also an Atari 8bit with a VBXE upgrade would benefit also.
NXP have some 16-bit variants of the 6502, in their automotive HCS12 series.
But even they resort to ARM Cortex cores, once you go 32-bit.
It’s an interesting concept. Kudos to anyone who gets an FPGA project to work. With open source tools, no less.
Actually, the HCS12 is an evolution of the 6800/6805 from Motorola, not the MOS 6502.
https://www.nxp.com/docs/en/supporting-information/WCSHCS12.pdf
if bill herd decides to make a commodore 256 i hope he remembers the bodge wire :-p