Preface

This manual describes the assembly language format, and how to write assembly language programs for the Intel 8080 microprocessor. Detailed information on the operation of specific assemblers is available in the Operator’s Manual and Installation Guide for each specific assembler.

Todo

Pages 1 and 2 of the scan (scans/page-01.png, scans/page-02.png) are the cover and the inside cover. Only the text above and the “© Intel Corp., 1975 / Rev. B” line were recoverable by OCR. Consider adding the cover artwork as an image.

Terms and Notation

Term	Description
Address	A 16-bit number assigned to a memory location corresponding to its sequential position.
Bit	The smallest unit of information which can be represented. (A bit may be in one of two states, represented by the binary digits 0 or 1).
Byte	A group of 8 contiguous bits occupying a single memory location.
Instruction	The smallest single operation that the computer can be directed to execute.
Object Program	A program which can be loaded directly into the computer’s memory and which requires no alteration before execution. An object program is usually on paper tape, and is produced by assembling (or compiling) a source program. Instructions are represented by binary machine code in an object program.
Program	A sequence of instructions which, taken as a group, allow the computer to accomplish a desired task.
Source Program	A program which is readable by a programmer but which must be transformed into object program format before it can be loaded into the computer and executed. Instructions in an assembly language source program are represented by their assembly language mnemonic.
System Program	A program written to help in the process of creating user programs.
User Program	A program written by the user to make the computer perform any desired task.
Word	A group of 16 contiguous bits occupying two successive memory locations.
nnnnB	nnnn represents a number in binary format.
nnnnD	nnnn represents a number in decimal format.
nnnnO	nnnn represents a number in octal format.
nnnnQ	nnnn represents a number in octal format.
nnnnH	nnnn represents a number in hexadecimal format.
|0|0|1|1| rp  |0|	A representation of a byte in memory. Bits which are fixed as 0 or 1 are indicated by 0 or 1; bits which may be either 0 or 1 in different circumstances are represented by letters; thus rp represents a three-bit field which contains one of the eight possible combinations of zeroes and ones.