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I want to write an assembler for the 8085 in C. I used GNUSIM8085 to review my knowledge of assembly.

When I learned assembly in my microprocessor class where I used ASMIDE with HCS12 Dragonboard. With ASMIDE and Dragonboard I used some instructions (forgot what they were) to display the data in different memory locations both before and after running the program and also an instruction to load and run the program.

It was something like this:

// Load assembly program
// Check memory values of A1H - A9H (for example)
// Run program (that modifies those memory locations)
// Check memory values of A1H - A9H

I forgot what exactly the instructions were but I want to know what the equivalent instructions are in with 8085. In GNUSIM8085 I can see the changes that have been made to memory in a GUI. Like this:

Frame

I want my assembler to be purely a command line application so I want something similar to ASMIDE. I can't find the instructions for loading and reading data from memory or for running a program in any instruction set.

I'm starting to think that it doesn't really have anything to do with the microprocessor itself and that the instructions I used in my microprocessors class were specific to ASMIDE.

In that case should I make up my own instructions for reading data, loading program etc?

Thomas Dickey
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Hauzron
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  • MANY years ago I developed a stack-based virtual machine, in assembly. Later a PDP-11 emulator, in C. In both cases I did develop my own commands to save/load/print values to screen/etc. Normally, such things occur through a memory-mapped interface and are complex/specific to the architecture. Develop your instructions and implement them through OS system calls. – Pynchia Jul 02 '15 at 12:48
  • so you are all over the map here and not clear what you are after. You want to write an assembler, is that part of your problem or that you can do without our help? needing instructions for reading and writing stuff is an application or debugger which is well down the road after you have an assembler and loader done. which means you already know the instruction set so why are you asking us about the instruction set. your board/chip/simulator if it has any I/O we need to know what board/simulator. If it is your own then just build a feature into the simulator to dump stuff. – old_timer Jul 02 '15 at 18:01
  • Alright thanks. I plan to work on loader and instructions for reading so I can test my assembler as I go along. I don't need any help writing the assembler (yet). I guess I'll use my own instructions for that stuff then. – Hauzron Jul 02 '15 at 21:29

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