Input/Output Files

Assembler Overview

8080/808S Assembler

Symbol Table Size

In overlay mode with 32K of Intellec memory, you can generate slightly more than 200 symbols. In nonoverlay mode with 48K of memory, you can have slightly more than 800 symbols. Each 16K memory increment adds 2000 symbols.

Macro processing uses a small amount of memory (for storing actual parameters) that could otherwise be used for symbols. The size or number of macro definitions does not affect symbol table space, however, since macro definitions are stored in a diskette file.

If you need more symbol table space, you can either add more Intellec memory or divide your program into smaller modules.

Source File

The input to the ISIS-II assembler is a source file, which can contain three elements:

•An 8080/8085 assembly language program, composed of instructions described in the 808018085 Assembly Language Programming Manual (9800301);

•Assembler directives, described in the same manual;

•Assembler control lines, described in the next chapter of this manual.

Only the instructions in your assembly language program are translated into exe- cutable object code.

Object File

The ISIS-II assembler creates its object file on a flexible diskette.

The object file contains machine language instructions and data that can be loaded into memory for execution or interpretation. In addition, it contains control in- formation governing the loading process (such as the starting address for program execution) .

The assembler can produce object files in relocatable object code format. The object modules produced by the ISIS-II 8080/8085 assembler can be loaded and executed anywhere in memory if they don't interfere with other programs they need for pro- per operation. The modules can also be linked to form a larger program. See the ISIS-II Systems User's Guide (9800306) for details.

List File

The list file is a formatted file designed to be output to a line printer or terminal. It includes listings of:

•Your assembled object code;

•Your source program;

•A table of symbols and their values;

•A summary of assembly errors.

The formats of these listings are described in Chapter 4.

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8080, 8085 specifications

The Intel 8085 and 8080 microprocessors were groundbreaking innovations in the world of computing, paving the way for future microprocessor development and personal computing.

The Intel 8080, introduced in 1974, was an 8-bit microprocessor that played a fundamental role in the early days of personal computing. With a 16-bit address bus, it had the capability to address 64 KB of memory. Running at clock speeds of 2 MHz, the 8080 was notable for its instruction set, which included 78 instructions and 246 opcodes. It supported a range of addressing modes including direct, indirect, and register addressing. The 8080 was compatible with a variety of peripherals and played a crucial role in the development of many early computers.

The microprocessor's architecture was based on a simple and efficient design, making it accessible for hobbyists and engineers alike. It included an 8-bit accumulator, which allowed for data manipulation and storage during processing. Additionally, the 8080 featured registers like the program counter and stack pointer, which facilitated program flow control and data management. Its ability to handle interrupts also made it suitable for multitasking applications.

The Intel 8085, introduced in 1976, was an enhancement of the 8080 microprocessor. It maintained a similar architecture but included several key improvements. Notably, the 8085 had a built-in clock oscillator, simplifying system design by eliminating the need for external clock circuitry. It also featured a 5-bit control signal for status line management, which allowed for more flexible interfacing with peripheral devices. The 8085 was capable of running at speeds of up to 3 MHz and had an extended instruction set with 74 instructions.

One of the standout features of the 8085 was its support for 5 extra instructions for stack manipulation and I/O operations, which optimized the programming process. Additionally, it supported serial communication, making it suitable for interfacing with external devices. Its 16-bit address bus retained the 64 KB memory addressing capability of its predecessor.

Both the 8080 and 8085 microprocessors laid the groundwork for more advanced microprocessors in the years that followed. They demonstrated the potential of integrated circuits in computing and influenced the design and architecture of subsequent Intel microprocessors. Their legacy endures in the way they revolutionized computing, making technology accessible to a broader audience, and their influence is still felt in the design and architecture of modern microprocessors today.