+Stephen Posted July 11, 2012 Share Posted July 11, 2012 Thought this may be of interest to a few people here: http://skilldrick.github.com/easy6502/ 3 Quote Link to comment Share on other sites More sharing options...
bpj1138 Posted July 21, 2012 Share Posted July 21, 2012 uhh... there is nothing "easy" about the 6502... Quote Link to comment Share on other sites More sharing options...
TMR Posted July 21, 2012 Share Posted July 21, 2012 uhh... there is nothing "easy" about the 6502... Learning 6502 is pretty easy, i picked it up when i was about fourteen just using a couple of books, a machine code monitor and, because it was the 1980s, a small group of school friends who were learning at the same time so going for it now with communities like this one to ask for help, huge archives of reference books online and other online resources like the one Stephen has linked to should if anything be easier. 2 Quote Link to comment Share on other sites More sharing options...
Rybags Posted July 21, 2012 Share Posted July 21, 2012 (edited) Probably the easiest CPU to learn. Tiny instruction set, few registers. Unlike many others, the instruction mnemonics and layout of the operands make plenty of sense. Edited July 21, 2012 by Rybags Quote Link to comment Share on other sites More sharing options...
snicklin Posted July 21, 2012 Share Posted July 21, 2012 I've done a few interrupts in the past but nothing at all major in 6502. I have to say, I've found it quite easy to pick up compared to other languages. I wrote a tiling routine in 'C' a short while ago and it took me several weeks to get it working. I've just written one in 6502 and I've developed in a few days (1 1/2 hrs per day). Most of that time was spent debugging it also. To me, the main hurdle that I need to overcome is knowing all the tips and tricks for making things as efficient as possible. This is something which I hope to pick up in time. To any modern programmers, I'd say it is probably on a par with Shell script programming for difficulty to learn. (I'm sure this is debatable!) Although I compile with MADS, I've deliberately decided not to use a lot of the features of MADS as I may tie myself down to this compiler. And also, it would take me ages to learn all the different ways of using it. I'm using pretty much standard 6502. I realise that I am missing out on plenty of features which could probably help me, but I don't want to be tied down. Quote Link to comment Share on other sites More sharing options...
Marius Posted July 21, 2012 Share Posted July 21, 2012 6502 code itself is rather easy. Programming something that works, looks, and sounds good on Atari 8bit is a different chapter, but that has more to do with the atari hardware (although I think a lot of the atari makes sense too). There are a few harder instructions, but most of the time you don't even need those (I speak of certain addressmode) Quote Link to comment Share on other sites More sharing options...
TMR Posted July 21, 2012 Share Posted July 21, 2012 6502 code itself is rather easy. Programming something that works, looks, and sounds good on Atari 8bit is a different chapter, but that has more to do with the atari hardware (although I think a lot of the atari makes sense too). Absolutely, it's the machines wrapped around the 6502 that are more challenging. The "trick" i reckon is not to jump in at the deep end, start with trying to make something that looks and plays like Warlok or Sea Dragon to begin with (or insert early but playable examples of another genre here =-) and use those to get an understanding of the machine to build on. Quote Link to comment Share on other sites More sharing options...
Pengwin Posted July 21, 2012 Share Posted July 21, 2012 I found 6502 pretty easy to pick up. What I found took me time, was learning to program (in any language). As has been said before, programming something that is functional, easy to use and pleasing to the eye can be the trial. The semantics of the language used are usually fairly simple. Quote Link to comment Share on other sites More sharing options...
snicklin Posted July 21, 2012 Share Posted July 21, 2012 I think another trick is knowing how to create the skeleton of the program that you want to run. For example, a game, you may know how to do some great DLI/VBI tricks, but if you don't have the game loop right, you won't make a game in any language. Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted July 21, 2012 Share Posted July 21, 2012 6502 code was the first I learned too, pretty easy... I got a *free* KIM-1 back in 1976-1978 when I was in High School and still have it Jay Quote Link to comment Share on other sites More sharing options...
bpj1138 Posted July 23, 2012 Share Posted July 23, 2012 Sure, it's easy, as long as all your variables are 8 bit and you don't need to use more than three registers in your program (two of which are just index registers and can't be used in arithmetic operations). Speaking of arithmetic, you only have addition and subtraction, you'll have to code multiplication and division yourself, if you're even able to do that, which most people don't (present company excluded, I'm sure). Quote Link to comment Share on other sites More sharing options...
snicklin Posted July 23, 2012 Share Posted July 23, 2012 I'm kicking myself that I didn't learn it earlier. Development time is so much quicker than I expected, especially thanks to modern debuggers. Quote Link to comment Share on other sites More sharing options...
carmel_andrews Posted July 23, 2012 Share Posted July 23, 2012 interesting, i thought the 2600 used a cutdown version of the 6502 namely the 6507 (which is also in the 1050 drive) and unless i am muistaken the NES used a 3rd party variant of the 6502 (the 2a03 or 2a07 i believe) which ran slightly slower then the atari versions of 6502 and 6502c proccessors Wan't it said that the 6502 was the risc processor of it's day, compared to the likes of z80 or 8080/8086/8 1 Quote Link to comment Share on other sites More sharing options...
TMR Posted July 23, 2012 Share Posted July 23, 2012 interesting, i thought the 2600 used a cutdown version of the 6502 namely the 6507 (which is also in the 1050 drive) and unless i am muistaken the NES used a 3rd party variant of the 6502 (the 2a03 or 2a07 i believe) which ran slightly slower then the atari versions of 6502 and 6502c proccessors They're all 6502 variants so, whilst the specifics might vary, the instruction set (which is what Easy 6502 deals with) is still valid across the board. 1 Quote Link to comment Share on other sites More sharing options...
Bryan Posted July 23, 2012 Share Posted July 23, 2012 So, has anyone given that little java 6502 simulator the acid test? Quote Link to comment Share on other sites More sharing options...
jakeLearns Posted August 20, 2012 Share Posted August 20, 2012 Man, I can't believe it - I tried that Easy 6502 site and I love it...how did I miss this all these years? LOL...normally I program in C, but next program will be in Assembler for sure. Quote Link to comment Share on other sites More sharing options...
+therealbountybob Posted September 2, 2012 Share Posted September 2, 2012 Just catching up on this forum... with all you 6502 programmers chomping at the bit I'm looking forward to some new (or improved) games over the next few years Quote Link to comment Share on other sites More sharing options...
jakeLearns Posted September 2, 2012 Share Posted September 2, 2012 I really liked that website, but after the easy 6502 course, I was still left wondering a bit, how am I going to organize the program....then, I bought this book called "Machine Language for Beginners" off e-bay. I have to recommend this book as well. If you are a programmer like me, but just want to be productive in assembler, this book has a path to getting started fairly quick, leveraging your existing knowledge. I'm sure my first effort won't be optimized like someone with experience could - but, I'm half way hopeful it won't be a big scrambled mess either - it may have some organization now! woot. Quote Link to comment Share on other sites More sharing options...
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