GNUSim8085 User Guide
Copyright 2018 Onkar Shinde
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GNUSim8085 was originally written by Sridhar Ratnakumar in year 2003 when he realized that no proper simulators existed for Linux. Since then it has been improved with features/fixes and ported to Windows thanks to help of various minds that are inclined to share knowledge.
GNUSim8085 makes it easy to learn the assembly language programming by providing an easy to use user interface. The application currently has following features.
- Program editor with interactive input wizard for the standard instructions
- Syntax highlighting in editor to distinguish between instructions, operands, comments etc.
- Support for standard instructions of the 8085
- Support for popular assembler directives
- Complete view of registers and flags
- Programming debugging using breakpoints or with step by step execution
- Easy inspection of stack and source code variables defined
- Easy inspection and manipulation of memory and I/O ports
- Printing of program from editor as well as assembled hex code
The user interface of GNUSim8085 consists of following components currently.
User can create new or edit existing program in editor. The editor has syntax highlighting to distinguish between between instructions, operands, comments etc. The ‘Load me at’ input allows specifying the start address of the assembled program.
Registers and Flags
Data conversion and access
User can easily convert data between decimal and hexadecimal format. The I/O ports and memory contents can be accessed by specifying the address. To update the contents enter new value and click appropriate update button.
This tab provides easy access to the memory contents. By default only first 1000 locations are shown. To see next locations, enter address in ‘Start’ text box and press ‘OK’ button. You can either edit hexadecimal values in Data (Hex) column or decimal values in Data column. When using hexadecimal values do not add h or H as suffix. For example simply enter A or 1B and not Ah or 1Bh.
This tab provides easy access to the I/O contents. You can either edit hexadecimal values in Data (Hex) column or decimal values in Data column. When using hexadecimal values do not add h or H as suffix. For example simply enter A or 1B and not Ah or 1Bh.