Programming

Last time, we looked at how to increment and decrement the values in registers. The code sample wasn’t very interesting, but learning how to use INC and DEC is a key step in learning how to build code that repeats tasks. A loop is a code sequence that executes over and over again until some […]

In this installment, we’re going to continue to learn more about the three primary registers in the 6502 processor (accumulator, X, and Y). We’ll also create our first simple subroutine. You can [download id=”1? format=”2?] for this program. Comments Before we do anything else, let’s take a moment to talk about comments. Comments are text […]

Unlike most modern processors, the 6502 series of processors has only three primary registers that you can use for manipulating data. A register is, basically, a slot within the processor that can contain a numeric value. On the 6502 and 65C02, these are each able to hold an 8-bit value. On the 65816, they can […]

Among programmers, there’s a long-standing tradition whereby one’s first program in any given language is one that simply displays the message “Hello world.” In this installment of Some Assembly Required, we’re going to create “Hello world.” I’m not going to really explain how it works this time around. We’ll get into understanding the programming next […]

Exciting news for the Apple II Community (and retro-computing at large). Google has launched GoogleCL, a command line API project that may enable developers to write Apple II applications that are capable of interfacing with Blogger, Calendar, Contacts and other Google services.

Over the coming weeks (or maybe months or even years), I’ll be posting a series of articles introducing you to the glorious, glamorous world of assembly language programming for the 6502 series of microprocessors. While, sure, there are plenty of other languages out there, and in this day and age, assembly is something of a […]