Titlebook: Apple IIc and IIe Assembly Language; Jules H. Gilder Book 1986 Chapman and Hall 1986 Apple.Assembly language.Calc.DEX.Division.Multiplicat

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Subroutines and Jumps,If you are familiar with BASIC’s GOSUB and RETURN statements you should have little difficulty understanding the two assembler equivalents:.If you are not familiar, I will explain.

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Shifts and Rotates,Basically, these instructions allow the bits in a single byte to be moved one bit to the left or one bit to the right. There are four instructions available:

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Multiplication and Division,Performing multiplication in assembly language is not too difficult provided that you have grasped what you have read so far. Unfortunately there are no multiplication instructions within the Apple //s 6502 (65C02) instruction set, therefore it is necessary to develop an algorithm to carry out this procedure.

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Floating a Point,So far throughout this introduction to assembly language programming we have only been concerned with ., or whole numbers. As in the real world though, . numbers also exist in the machine code world. A floating point number is one that contains a decimal point (although in binary this is more correctly referred to as a ‘bicimal’ point).

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Eliot: an American use of symbolismation code) in the range 0 to 255. To create a machine code program, we need simply to POKE successive memory locations with the appropriate operation codes—”opcodes” for short. For example, to store the value 5 at location 1500 (in other words, to do the machine code equivalent of Applesoft BASIC’S

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The Case of the Missing Subject, not wishing to baffle you with the wonders of modern computer science, let’s try to simplify matters somewhat and say that each instruction is stored internally as a binary number. Decimal numbers are composed of combinations of 10 different digits, that is, 0,1,2,3,4, 5,6,7,8, and 9 and are said t

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