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The MOS 6502 and the Best Layout Guy in the World

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Re: The MOS 6502 and the Best Layout Guy in the World

#21

Intel Core 2 - Yorkfield, 45 nm process technology, Number of Transistors: 820 Million MOS 6502, Number of Transistors: 3510 So in theory, a chip with 65536 MOS 6502 cores each with 64K of internal RAM (4Mb cache) could be made.

Sure, if you completely ignore all of the extra circuitry for the on-chip network and cache coherency and everything else you would need. Transistor density is far from the limiting factor in the number of cores we can wedge into a single system.

Re: The MOS 6502 and the Best Layout Guy in the World

#23
I loved the 6502. Around that era I programmed the SC/MP, Z80, the 8080 and the 6800. Although the Z80 was more powerful, the 6502 holds a special place in my heart as it was the first CPU I worked with and I loved the simplicity of the instruction set.

My crowning achievement was a multi-threaded kernel for a CNC punch. Since the stack was at a fixed memory address and there was no PUSHA, I had to change threads (in response to an IRQ) by sequentially pushing the registers on to the stack and then swapping the stack with a block copy. It worked! Crazy :/

I loved reading this article - thanks for posting. Awesome stuff! Makes me want to code my own circuit emulator :)

Re: The MOS 6502 and the Best Layout Guy in the World

#24

Intel Core 2 - Yorkfield, 45 nm process technology, Number of Transistors: 820 Million MOS 6502, Number of Transistors: 3510 So in theory, a chip with 65536 MOS 6502 cores each with 64K of internal RAM (4Mb cache) could be made.

Sure, if you completely ignore all of the extra circuitry for the on-chip network and cache coherency and everything else you would need. Transistor density is far from the limiting factor in the number of cores we can wedge into a single system.

If you assume that there is no cache (only on-die memory) and that memory is not shared between cores, things become much simpler and scale more linearly. Core-to-core communications and plenty of other details remain to spend man-years ironing out, but it seems like it would be possible to approach 64k cores or at least 16k.

Re: The MOS 6502 and the Best Layout Guy in the World

#25
post #5
post #3

Earlier quoted context omitted.

That's the sensation of working with someone who's incredibly good. And, BTW, the 6502 was a work of art. Simple, elegant and fast (even at 1 MHz), it ran rings around the Z-80's you found in more expensive computers of the time. Plus, it was delightful to program.

Plus, it was delightful to program. Simple maybe, but not delightful to program. I don't know of any assembly language that is delightful to program. BTW, I knew someone from junior high & high school who could write code for the 6502 using a hex dump with amazing speed. You might have heard of him: Randy Linden.

Heh, yeah I still remember 6502 opcodes... 4C xx xx is jmp absolute, 20 xx xx is jsr (jump subroutine) absolute, A9 xx xx is load accumulator absolute, 8D store accumulator, 60 is rts... I could go on.

Typing shit in to the hex monitor for a few years will do that :)

Re: The MOS 6502 and the Best Layout Guy in the World

#26
From Jordan Mechner's diary of the development of Prince of Persia (POP was originally coded in 6502 Assembler. It took him four years). Reading Jordan's full diary will take you at least eight hours but it is well worth it.

> We chatted for an hour about peripherally related topics. Broderbund, corporate America, the rat race, capitalism, freedom. I was seducing him. 

At the critical psychological moment, I remarked: "You know, all my clipping is done on the byte boundaries."

There was a pause

http://jordanmechner.com/old-journals/page/33/

April 3, 1989

Re: The MOS 6502 and the Best Layout Guy in the World

#27
post #7
post #6

Earlier quoted context omitted.

I believe the 6502 could do things faster than the Z80. I once implemented the exact same program on a 6800 and a Z80. The 6800 is very close to the 6502. Speed wasn't an issue, but the Z80 version was noticeably bigger. And also felt more quirky to program.

I believe the 6502 could do things faster than the Z80. Right, I was hoping someone might remember specifics. I don't think this is really true, in general. The 6800 is very close to the 6502 Not really.

The 6502 was faster at accessing memory. I remeber Elite running a lot better on a 2MHz BBC Micro than on any 3.58MHz Z80 based micro, like the MSXs.

Re: The MOS 6502 and the Best Layout Guy in the World

#28

I loved the 6502. Around that era I programmed the SC/MP, Z80, the 8080 and the 6800. Although the Z80 was more powerful, the 6502 holds a special place in my heart as it was the first CPU I worked with and I loved the simplicity of the instruction set. My crowning achievement was a multi-threaded kernel for a CNC punch. Since the stack was at a fixed memory address and there was no PUSHA, I had to change threads (in…

Ditto that. My first programs were in assembly on the 6502, and I'm thrilled to see it getting this attention. I'm just sorry that I don't still have the KIM-1.

Re: The MOS 6502 and the Best Layout Guy in the World

#29
post #24

Earlier quoted context omitted.

Sure, if you completely ignore all of the extra circuitry for the on-chip network and cache coherency and everything else you would need. Transistor density is far from the limiting factor in the number of cores we can wedge into a single system.

If you assume that there is no cache (only on-die memory) and that memory is not shared between cores, things become much simpler and scale more linearly. Core-to-core communications and plenty of other details remain to spend man-years ironing out, but it seems like it would be possible to approach 64k cores or at least 16k.

Might be able to peel out the BCD stuff from the 6502 to free up a little additional space and approach communication between cores kinda like the "handshake bus" GreenArrays chips use: http://greenarraychips.com/home/documents/greg/PB003-100822-...

Re: The MOS 6502 and the Best Layout Guy in the World

#30

I loved the 6502. Around that era I programmed the SC/MP, Z80, the 8080 and the 6800. Although the Z80 was more powerful, the 6502 holds a special place in my heart as it was the first CPU I worked with and I loved the simplicity of the instruction set. My crowning achievement was a multi-threaded kernel for a CNC punch. Since the stack was at a fixed memory address and there was no PUSHA, I had to change threads (in…

Ditto that. My first programs were in assembly on the 6502, and I'm thrilled to see it getting this attention. I'm just sorry that I don't still have the KIM-1.

I was planning on buying a KIM-1 when my dad surprised me by buying an Apple II. I didn't end up writing anything in assembly on the Apple II, though. My first assembly language was IBM-370 in college. I wish now I had started with the KIM-1, though.
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