Linked by Thom Holwerda on Sun 8th Jul 2012 22:54 UTC
General Development "In this tiny ebook I'm going to show you how to get started writing 6502 assembly language. [...] I think it's valuable to have an understanding of assembly language. Assembly language is the lowest level of abstraction in computers - the point at which the code is still readable. Assembly language translates directly to the bytes that are executed by your computer's processor. If you understand how it works, you've basically become a computer magician." More of this, please.
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I'd be remiss...
by whartung on Mon 9th Jul 2012 17:43 UTC
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I'd be remiss to not mention

It's an active forum with some 6502 grognards. One thread at the moment is the progress of guy tracing circuits of the 6502 from a micrograph of the chip.

Other threads involve some folks who are working on the "65Org16" CPU, which is essentially a 6502 with everything stretched to 16-Bits. They have running examples in FPGAs.

Others are working on 65816 boards.

Over Christmas break, I decided to write my own 6502 simulator, and an assembler, and I've got Fig-Forth running on it, so the trials and tribulations of that are posted over there. I'm in the processing of adding ANSI support to my simulators terminal so I can make a screen editor for the Forth.

Simply, if you're interested in the 6502 (not necessarily the Apple/C64/Atari), it's a great place to hang out.

However, I must recommend the Altirra Hardware Reference manual, available from, which is just chock full of really crazy low level stuff that the developers of this Atari 800+ emulator discovered. You learn a lot about the nuances of hardware design when you try to reverse engineer it.

I'd also be remiss not to mention, which is a transistor simulation of the chip. If you want to know what happens when the NMI pins fires during a BRK instruction, this is the place to go.

The 6502 remains as having a pretty active following, the chips are still in production, it's a good chip and has a cool legacy to it.

Edited 2012-07-09 17:44 UTC

Reply Score: 4