CS/A65: A 6502 computer with USB, Ethernet and co-processors • Hacker News Board

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#11

Post by abdulhaq » Fri, Aug 20, 2021, 7:10 PM UTC

amrcnimgrnt wrote: post #2

Andre Fachat also wrote a pre-emptive multitasking kernel for the 6502: http://www.6502.org/users/andre/osa/oa1.html This is basically the same CPU as in the NES.

It feels weird to me that some hackers don't know what a 6502 is! Sign of my age I guess.

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#12

Post by [deleted] » Fri, Aug 20, 2021, 7:12 PM UTC

salamandersauce wrote: post #4

the-dude wrote: post #3

Earlier quoted context omitted.

And in the BBC B, Electron and Commodore 64.

And Apple II and Atari 2600 and 8 bit computers.

[deleted]

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#13

Post by retrac » Fri, Aug 20, 2021, 7:13 PM UTC

skyde wrote: post #6

Noob her! why use a 6502 versus another 8bit cpu like Atmel AVR? Is there any advantage? Does it consume less electricity while running at similar speed ?

Sentimentality. The 6502 has been around for almost half a century now. Often the processor in an older programmer's first computer or video game system. It's horribly limited, but assembly programming for the 6502 has become a kind of code golf.

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#14

Post by cdcarter » Fri, Aug 20, 2021, 7:21 PM UTC

Always love to see a 6502 post here on HN. It's a really unique processor compared to other 8-bit processors at the time. With only one general purpose register, and memory mapped IO, the 6502 offers a ton of "addressing modes" to solve problems that the 8080 would solve with register transfers.

Ben Eater (http://beneater.net/) makes a neat video series and accompanying product kit where you build a 6502 on a breadboard, if you're looking for something a little more approachable than this (very cool) project!

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#15

Post by deelowe » Fri, Aug 20, 2021, 7:35 PM UTC

glonq wrote: post #5

Pros and cons of this versus Commander X16 ?

X16 is going to be more for folks who want something that just works and they can play around with in software

Projects like this are more for folks who are looking to build their own computers from scratch. Typically, this is for someone who's more into hardware.

Personally, I enjoy both. I have probably 6 or so kit computers at this point. FWIW, the two that I've enjoyed the most are Ben Eater's breadboard 6502 project and the nand2tetris series which is all done in software.

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#16

Post by schemescape » Fri, Aug 20, 2021, 7:42 PM UTC

skyde wrote: post #6

Noob her! why use a 6502 versus another 8bit cpu like Atmel AVR? Is there any advantage? Does it consume less electricity while running at similar speed ?

I'm not 100% confident about the dates, but my understanding is that the author's project started in 1989, before AVRs were developed (1996).

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#17

Post by royjacobs » Fri, Aug 20, 2021, 8:02 PM UTC

cdcarter wrote: post #14

Always love to see a 6502 post here on HN. It's a really unique processor compared to other 8-bit processors at the time. With only one general purpose register, and memory mapped IO, the 6502 offers a ton of "addressing modes" to solve problems that the 8080 would solve with register transfers. Ben Eater ( http://beneater.net/ ) makes a neat video series and accompanying product kit where you build a 6502 on a bread…

It's a really fun architecture, agreed. I spent the last few months writing an assembler, formatter and language server for 6502 code. If you're interested, it's available at https://mos.datatra.sh

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#18

Post by z-nexx » Fri, Aug 20, 2021, 8:07 PM UTC

the-dude wrote: post #10

skyde wrote: post #6

Noob her! why use a 6502 versus another 8bit cpu like Atmel AVR? Is there any advantage? Does it consume less electricity while running at similar speed ?

I assume memory lanes.

And address lanes. Don't forget the ALU, etc.

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#19

Post by tyingq » Fri, Aug 20, 2021, 8:18 PM UTC

skyde wrote: post #6

Noob her! why use a 6502 versus another 8bit cpu like Atmel AVR? Is there any advantage? Does it consume less electricity while running at similar speed ?

The Atmel has a modified harvard architecture, so it's easier to use as a microcontroller than to run an OS on. Where there are lots of available OSes for 6502, Z80, etc.

Re: CS/A65: A 6502 computer with USB, Ethernet and co-processors

#20

Post by spicybright » Fri, Aug 20, 2021, 8:18 PM UTC

cdcarter wrote: post #14

Always love to see a 6502 post here on HN. It's a really unique processor compared to other 8-bit processors at the time. With only one general purpose register, and memory mapped IO, the 6502 offers a ton of "addressing modes" to solve problems that the 8080 would solve with register transfers. Ben Eater ( http://beneater.net/ ) makes a neat video series and accompanying product kit where you build a 6502 on a bread…

A while back I tried writing an Atari 2600 game and got about half way (got sprites, collisions, level, just no goal)

The console uses a slightly cheaper version, the 6507 I think. Same chip, just smaller address line and no interrupts (!)

Instead you ran a "wait for the cathode ray to reach the right side of the screen" in order to time everything correctly.

Very fascinating stuff, I recommend anyone interested in the above dive in and give it a shot.

All you need is an editor[1] (I found one online!) and the stella manual[2].

There's something nice about having the entire machine spec in one book instead of leaning on stack overflow...

[1] https://8bitworkshop.com/v3.8.0/?platform=vcs&file=examples%...

[2] https://cdn.hackaday.io/files/1646277043401568/stella.pdf