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Questions tagged [assembly]

Low-level programming language used to send instructions (machine code) directly to a microprocessor. For assembling hardware, use [computer-building] instead.

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What are available embedded computers with GPIO for AI or Machine Learning

I would like to know what are available embedded computers with GPIO for AI or Machine Learning. I want to know it should have more processing power than raspberry pi 3. Also, I want to know is it ...
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1answer
11 views

What format crash utility's disassembler uses to output assembly instructions?

Crash utility can disassemble kernel functions. but what format it uses? Which is first, source or destination? inst src, dist or inst dist, src This is what I am asking about: crash> dis ...
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93 views

TSL (Test and Set Lock)

I want to ask that whenever the high level language is converted to low level language then would it be going to respective to each other? For example if I am going to convert the following high ...
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1answer
132 views

What is the type of the UART chip used by Virtual Box?

Based on my understanding, a UART chip is used to control the serial port (the programmer manipulates the UART registers in order to access the serial port). There are many types of UART chips (for ...
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1answer
155 views

What happens when assembly code is translated into Object code?

I am interested in System Software development. I have been analyzing the working of a compiler for a few days. An Assembly code generated by a Compiler(say) clc has an opcode f8 and I am sure that ...
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2answers
62 views

How can I represent the output of 250500*250500 in 32-bit word?

We have 250500*250500 = 62,570,250,000. How can we represent this using low and high? I know that the biggest number that can be represented in 32 bits is 4,294,967,295 (2^32 - 1)
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1answer
125 views

How to get values for BIOS parameter block in a VBR?

I am creating a VBR, which recides on the first sector of a Volume. The VBR must have BIOS Parameter Block if FAT file system is to be implemented. When working on my disk(say), I could manage to find ...
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2answers
2k views

How does a MBR in USB drive works?

Every USB drive has a Master Boot Record. MBR contains Partition Table. While on a normal HDD, The MBR can have 4 partitions and the MBR has information about the partitions. Coming to USB, it has ...
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1answer
278 views

How to know from what microsoft package/update a .dll file comes from?

There are plenty of specific missing X.dll requests here. I would like to know how to get where does a .dll file should come from, especially a microsoft .dll. I have a missing assembly error on my ...
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1answer
1k views

What actually happens when I run “cli; hlt” on my Linux system?

So I recently figured out that there's a HLT opcode for halting the CPU. Cool, let's see what happens! user@box:~$ cat > test.c int main(void) { __asm__("HLT"); return 0; } user@box:~$ gcc ...
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2answers
167 views

Do I need an embedded system, custom os, or embedded os? [closed]

I have been toying around with the idea of developing a "kiosk" for in-home users that may or may not have knowledge of computers or how to use them. For sake of argument lets say my "kiosk" is ...
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2answers
468 views

Does a USB drive have head, track etc?

I wrote a bootloader and I need it to be written to a USB drive. Since I am on Windows, my bootloader must support file systems such as FAT32 and FAT16 etc. I have used BPB (BIOS Parameter Block) for ...
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63 views

How does a computer add 2 numbers at its lowest level?

Most memory addresses only hold 8 bits (1 byte). This means it can hold a number up to 255. What if I wanted to store 511? I would use 2 memory addresses and store it like this 00000001 11111111 ...
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1answer
132 views

Latency semantics of read registers on x86 ASM

Per A. Fog's instruction tables, an Ivy Bridge has a 3 cycle latency on a MOV instruction. So the following will take 3 cycles to move RAX into the address in RCX: mov [rcx], rax My ...
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1answer
2k views

Meaning of “?” (Question Mark) in assembly

For some project i am required to draw the memory diagram of assembly code.I know that in assembly language "?" means, values are un-initialized. But what happens exactly in memory when i put "?"? ...
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1answer
766 views

How are instructions and data stored in memory? [closed]

I am debugging a C# program and the disassembly view show this: 0x006E2813 pop ebx 0x006E2814 pop esi So pop ebx is stored in 1 byte(in one single address), but how can that ...
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2answers
78 views

Why do some processors have unofficial codes and/or bugs? [closed]

Lately I am writing (or trying) an emulator for the 6502 NES CPU. I am learning many many things, some of them really surprise me and I was wondering what's the explanation for those, in particular, ...
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50 views

Direct access to video card using a microcontroller or DOS-based OS [closed]

I am trying to build a handheld 3D positioning system that can track in real-time (1000 Hz) a handheld 3D position in reference to a virtual 3D object. To be more specific: I have a robotic arm ...
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0answers
26 views

Show all running tasks in Assembly

Is it possible to show/log everything what the CPU does? The CPU knows what it executes, so it could print the running threads/tasks on the screen or in a file.
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3answers
2k views

Vim assembly formatting

Vim is not properly indenting assembly code, regardless of if I want it to do it automatically or if I try gg=G it'll just says ## lines indented even though it didn't change anything and all my text ...
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4answers
12k views

How to check if a binary requires SSE4 or AVX on Linux

On Linux,/proc/cpuinfoallows one to check all the CPU flags the machine has in a simple way. Usually, if a program requires a superset of a machine's instruction set, the easiest way to determine this ...
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1answer
220 views

Would x86 assembly work on x64 processors?

Would x86 assembly compile on an x64 machine and still work properly? If not, what is the difference between x86 assembly and x64 assembly?
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0answers
203 views

Mouse I/O in assembly 68K [closed]

I had a problem with reading the position of mouse in screen in assembly 68K, what I have to do? I even read the the help of Easy68K, but I couldn't understand what it exactly says. I would be ...
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2answers
77 views

Is there risk of damaging my system or losing data while practicing is assembly language

I'm going to learn assembly, I have downloaded WinAsm IDE and MASM32. Assembly programing usually involves low level stuff , so before I start I wanted to ask if there is any risk of damaging my ...
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1answer
62 views

Method to view machine or assembly code supporting a raster or vector image

I'd like to be able to view either code for a selected image. For example, if I have an image of a flower, what does it look like to the machine or how would the machine express it using it's machine ...
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2answers
92 views

Can any compiled-language code be traced, line-by-line, to individual bits of each CPU-instruction in binary? [closed]

I realize we can dump equivalent assembly from C++ code using many debuggers and such. But what about binary code? The formatting of bits in each byte(s) that make up the actual machine instructions, ...
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1answer
1k views

Program Run on DosBox Doesn't Generate Output Files

I'm using windows 8.1 , 64 bit version , and I have a 16 bit assembler program which I'm trying to run using DosBox. The program doesn't seem to generate output files , despite being called properly ...
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1answer
9k views

Where can I find the instruction sets for Intel or AMD microprocessors? [closed]

I'm sorry if these are stupid questions or if they don't pertain to this website. I don't really know where else I could ask this. Okay first of all, I don't really understand how instruction sets on ...
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2answers
1k views

What is the point of loading a program into RAM if virtual memory is just going to put it back on the disk?

After reading this question about virtual memory, I was inspired to ask: it seems like walking in a circle when a program is run it is loaded into memory from disk but then there's not enough space in ...
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3answers
25k views

Latency of CPU instructions on x86 and x64 processors

I'm looking for some table or something similar that could help me to calculate efficiency of assembly code. As I know bit shifting takes 1 CPU clock, but I really looking how much takes addition (...
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1answer
1k views

when i open new file it insert code in notepad++

First i want to tell you that i now i only use notepad++ for assembly language. and i have made assembly my default language by reading this here so when i open new file it highlight as assembly now ...
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1answer
3k views

Mounting Drive to DosBox and using Debug.exe

I am trying to track down the MBR on a scavenged Hard Drive. The hard drive won't boot so I've been trying to change the MBR through DEBUG.exe. The problem starts with my 64 bit machine because debug....
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3answers
23k views

No video signal at boot with custom built computer

After booting my custom built computer, neither the VGA nor the HDMI methods from the video card seem to emit any signal to the display. I have tested both a regular VGA screen and a modern HDMI ...
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1answer
226 views

Can I show an image with BIOS interrupts or assembly? [closed]

I am trying write a simple bootloader, and I want to show an image when my bootloader starts. How can I do this? I am using assembly with nasm assembler.
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1answer
121 views

Best assembler -> C book? [closed]

I know there are good assembler books and there are good C/C++ books, but is there a book which maps the two programming languages/levels together?
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2answers
3k views

Run 16 bit program on 64 machine bit without dosbox

Is there an program that you can type into command line or terminal with a set of parameters to run a 16 bit program? Such as: "run16bitprogram.exe 'path/to/program/test.exe'" and just output whatever ...
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2answers
540 views

Intel assembler/architecture documentation?

Would anyone know where the best "official" Intel documentation regarding the low level architecture/assembler internals would be? How the ESP works, the various registers- fetching values from RAM ...
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2answers
7k views

How do you write a bootloader to the MBR?

I was trying to write a bootloader in the assembly language to a USB drive, to test it on another computer. The bootloader (should) work with intel processors. The computer I'm testing it on (windows ...
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2answers
975 views

Emacs - How can I enable tab indentation in Assembly?

I have been using emacs for c programming and now that I want to write some Assmebly code, when I press tab, emacs just inserts the spaces. How can I force it to ident the current line with the Tab ...
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2answers
1k views

Is there any way to see what my CPU is doing at the “assembly level”?

I was looking at how Assembly Language works, because I want to learn how the complex and fancy things my computer does actually happen at the CPU register/hardware levels. Is there any way to see ...
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2answers
3k views

How to see all the bits of a file?

I'm looking for a way to see all the bits of a file. I want to see all the 01s of my file, because I want to know what changes exactly happen when I edit a file using an closed-source application. ...
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1answer
3k views

Understanding the nop byte(s)

Ok, so I was reading through the AMD64 manuels and knowing that nop is really an xchg eax, eax, I looked at the xchg and found something interesting, that it seems a byte can be encoded into the ...
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1answer
941 views

“nop; jmp short” vs. “jmp short; nop”

Ok, first let me get this straight: This is not about micro optimization. But, I know in bootloaders on the partition, a lot use the jmp short; nop coding. But it is to my understanding that the less ...
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1answer
435 views

Find out what sectors are a file on a hard drive?

How would I go about finding what sectors a file's data is on so i would be able to delete the file via bootable assembly code. Eg: File: C:\system.sys Location: sector 1837,1739,2736 etc Or some ...
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3answers
5k views

Why can't we understand the content of a binary file after compiled?

As far I know, every program consists of a pack of processor instructions with some specific data variables(float, int, char...) to work on the processor registers. So, the first thing that I ...
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5answers
766 views

Old Technologies About Floppy

I have a floppy disk with an unknown FS-(FileSystem). I want to make a copy from it but I can't because both Windows and Linux seem to be unable to read from it. I tried many of the most popular apps ...
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2answers
921 views

Understanding 8086 instruction encoding

I am trying to understand 8086 instruction encoding. Even though I found a general instruction and a bulky reference I still don't get it. Could you please explain me how the following "translations" ...
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3answers
8k views

How prevalent are old x64 processors lacking the cmpxchg16b instruction?

The cmpxchg16b instruction for doing atomic 128 bit memory exchanges is not supported on old versions of the x64 processor but it seems like this has been supported by newer versions of the processor ...
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1answer
530 views

how to assign Strong Name to an Assembly?

I have created strong name using - sn -k C:\strong.snk nao how to assign this key to any assembly? and where I have to use gacutil?
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1answer
59 views

linux and assembly - blocking [closed]

does Linux block ports and interrupts for user programs use ?