Free: Building your own 6502 computer (article)

6502 PRIMER: Building your own 6502 computer

http://wilsonminesco.com/6502primer/index.html

http://forum.6502.org/viewtopic.php?f=1&t=2157

(I have permission to post about his article on the web.)

I think it's great that people are still using the same cpu that was used in the good old commodore 64! very fond memories of that computer.

I think it is a good read and Commodore might have been considered state of the art at one time. I read that Commodore used transistors as resisters because an open gate on a chip offers resistance. This dual use of components makes me stop and ask if I know what I'm looking at.

I bought a Commodore 16 off of ebay and I haven't plugged it in yet. I also know that I can buy a 6502 or 65C816S computer kit from Apatco and there is a large CD library from the Toronto Pet User group and I found back issues of Compute!, Compute's Gazette and Ahoy. I also have books on ML language by Jim Butterfield. I just haven't decided which platform I want to build on.

I am actually looking at using the SWINSID which is an emulated version of the SID chip used in the commodore 64. I will be using it for my latest LED game!

Many parts of the 6502 primer are applicable to practically any digital project.


That ARM-based one is at http://www.swinkels.tvtom.pl/swinsid/
There's also this Atmel ATmega-based one: http://roboterclub-freiburg.de/atmega_s ... gaSID.html


Although the x86 has made more progress in the last 30 years, the 6502 has come a long way too, with the CMOS version having more instructions and addressing modes and having the bugs removed and more signal pins added, and turning the clock speed way up. Current-production ones are conservatively rated for 14MHz and will usually do 25MHz if the surrounding parts can support it. The fastest ones are at the heart of custom ICs and run above 200MHz, which would be worth about 400MHz (100 MIPS) of a PIC16.

Then of course there's the 65816 which is, as BigDumbDinosaur (his screen name) put it, "a 6502 on steroids." I probably won't ever write a separate primer on the '816 but perhaps an article would be in order debunking the unfounded fears people seem to have about the '816, especially about the multiplexed address bus (which you don't have to use to get a ton of benefits) and the mode bits (which you can leave nearly untouched in many applications). When you're constantly dealing with 16-bit numbers, I find the '816 to actually be much easier to program.

The 6502 primer will keep getting improved but the major page addtion since the original post here is the circuit potpourri page which shows how to interface a lot of general-purpose things, some examples having accompanying code linked. There's a lot more coming but I'm taking a little break first.

Our older son showed a lot of technical ability very early in life, and I got him started on C64 when the other kids were on Windoze and Mac. The point was to get him into the insides and keep him from being content to be an appliance operator. He went a long way on C64 but never got into assembly language or much into the actual electronics. Today at age 24 he is somewhat of a networking expert, maintaining the computer networks and servers and phone networks at two school campuses, all self-taught. He is very strong on Linux too. Recently when he was telling me about a problem he solved at the school, I asked him, "How is it that you know so much about this and yet don't know what a simple NAND gate is?" He said, "Because if the NAND gate goes out, I'll replace the mother board or whatever it was on," IOW, very much at the systems level, not the component level.

I had no idea that the 6502 was still evolving. I think that's great! I also didn't know that there was such a community for the CPU, it is obviously still going very strong.

the C64 was our first computer, in-fact I still have one, unfortunately I didn't ever get to program on it (I was only about 5 when we got one) but I did enjoy the games. I didn't get into programming until 2007

Actually the 6502 community and expertise are increasing at 6502.org, and there are good things happening there that I would not have expected just a few years ago.

Even better!