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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

With all due respect Garth, what if the 6502 did have 16 registers like the 1802 had, with the instruction set of the 6502 while maintaining speed of the 6502? Then what would you say?

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

According to my copy of Computer Architecture by Hennessy and Patterson, chapter 2.11, register graph colouring work best with "at least 16 (and preferably more) general-purpose registers".

The RCA 1802/1804 and SWEET16 hits the sweet spot. I believe 6502 also would if the zero page was more accessible, hence my ruminations on a dual port architecture. The only snag is that the LDA (zp, x) results in half of these to be unaligned. Perhaps a LDA (zp, 2x) would overcome this and also the INX; INX that can be found in various source code.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

The EE Life section of EE Times has an article titled "Is 8 bits dying?" where 8- and 32-bits processors are compared:
http://www.eetimes.com/electronics-blogs/other/4389890/Is-8-bits-dying-

The arguments are interesting, most I guess are familiar to most here. One that I miss is ease of programming, which is why I put this comment in this thread.

One that I do not understand is that of chip floor area. It is argued that old processors are designed with old rules. Well, if these are, like ARM, designed in Verilog or VHDL, the tool chain should optimise to modern rule sets. Or am I missing something here?

Incidentally the article is a follow up on one called "Trends in embedded software design"
http://www.eetimes.com/discussion/other/4372183/Trends-in-embedded-software-design?Ecosystem=embedded
Here more strange arguments are fielded such as the need for networking required 32 bits. Odd. Networking was quite well working in the BBC model B, and TCP/IP has been implemented in other 8-bit machines. Anyway, for huge volume products networking and over the air update is not always even desirable.

For both I note extensive libraries are not put forward as an argument.

I don't think it's saying that old architectures are necessarily built with old design rules. Rather, it's that 8-bit micros available today include offerings of old designs made on old processes (maybe run in old factories)

The article has a lot of pros and cons with no firm conclusion, but then it is aiming to predict the future!

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

I do professional embedded work, and the niche where 8 bit has sufficient advantage over 32 bit is getting smaller all the time. I used to work with 8 bit CPUs, but now I do everything with ARM (mostly Cortex M0/M3 nowadays). Power is just as low as 8 bit, packages are just as small, prices are lower, and development is easier. I can still see a niche for ASICs running an 8 bit CPU in very high volume, extremely low power productions for a while, though.

This is an interesting article. The decision which processor to use in an embedded computer design depends on a number of factors. Some of them are soft - like available skills. If everything runs on / everyone uses ARM, this will be it, even in applications that do not necessarily need it.

I think here it makes sense to think about a scalable architecture - one that goes from 8 bit up to 32 (or more) bits - using the same tool chain, interoperable (i.e. compatible), with an easy to learn instruction set, ...

Ok, that certainly fits my #65k extension of the 6502 up to 64bit, although I don't think that this one will win But a nice coincidence

André

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Author of the GeckOS multitasking operating system, the usb65 stack, designer of the Micro-PET and many more 6502 content: http://6502.org/users/andre/

Interesting. So I took a closer look including through the Usenet Newsgroup comp.arch which I believe should be called comp.archaeology...

Anyway, the 1802 has a few warts in terms of design.

• I/O straight into the ISA is clever for a few things but sure eats up a lot of code space, so does having to address 16 registers too, in an 8-bit opcode
• Using an 8-bit accumulator to move data around 16 register of 16 bits each was not a good idea
• The design makes subroutines and parameter passing very painful

Things improved with the 1804/1805 using opcode 68 as a prefix; unfortunately the ISA was not fully developed.

Interestingly SWEET16 avoids many of the problems since the accumulator is in reality R0. Thus a SEA (Set Accumulator pointer) would have overcome this and also easily lent itself to double width accumulator.

As a bonus, the later extensions also brought in a DBNZ loop branch instruction.

I did that too many years ago now so I am no longer as up to date on the market as I once was.
How about licensing costs? ARM makes a pretty penny and I would still expect ARM cores to be more expensive than 6502.
Like RFID? I hear plans on RFID on nearly all packaging with tagging and a little logging. That would be an interesting market.

Licensing costs could be a problem for ASIC development, which is where 6502 cores (or similar) would have an advantage. If you buy off-the-shelf ARM devices, like I do, the licensing cost would be rolled in the price of the device. In practice, these prices are quite competitive.

This is a fun topic and there is no reason to let it go, particularly when I found that 6502 has a virtual sibling in the 65EL02:
http://www.eloraam.com/nonwp/redcpu.php
http://www.eloraam.com/?p=255
Eloraam has extended the architecture with a new stack and autoincrement features and a smattering of other features.

It appears that 6502 was considered by Notch before making his DCPU-16 for the game 0x10c
http://gamegenus.blogspot.com/2012_04_01_archive.html

Just the other day i installed the tekkit pack for Minecraft, and there i found the mentioned 6502 emulator, and the forth disk, i quickly connected it all, but i didn't know how to start the contraption. Ill give it another try, and maybe convert my server to run the mod.