x16 PRos

Running x16-PRos on Real Hardware

PRos is designed for 1.44 MB floppy disks but can also run from a USB flash drive. Follow these steps to set up PRos on real hardware. Use the .IMG image for persistent storage or the .ISO image for a live CD experience without saving changes.

Select the Device

Choose a USB flash drive or floppy disk to write the PRos system image. For USB drives, ensure the drive is formatted as FAT12. The .IMG image supports persistent changes, while the .ISO image is for temporary, live sessions.

Write the Image

Download the PRos system image (.IMG or .ISO) and use a tool like Rufus to burn it to your USB drive. Select your USB drive and the image in Rufus, then click START. Wait for the process to complete before safely ejecting the drive.

Configure BIOS for UEFI Systems

PRos relies on BIOS system calls and does not support UEFI directly. If your computer uses UEFI, enable Compatibility Support Module (CSM) in the BIOS settings. Enter the BIOS setup by pressing keys like F2 or DELETE during boot (check your motherboard manual for the exact key). Locate and enable CSM support.

BIOS CSM Settings — Change DISABLED to ENABLED for CSM support.

Access the Boot Menu

Restart your computer and enter the boot menu (typically using F8, F11, F12, or ESC). Select the USB drive option labeled "USB" (not "UEFI") to boot PRos.

Boot Menu Selection — Select your USB flash drive from the boot menu.

Boot PRos

Press ENTER to start the boot process, which takes approximately 2–5 seconds. Upon first launch, you’ll see the PRos installation screen.

Running x16-PRos on Emulators

Emulators are ideal for developers and testers. PRos supports several emulators, with QEMU being the most straightforward option. Follow these steps to run PRos on QEMU.

Install QEMU

Install qemu-system-x86_64 or qemu-system-i386 using your package manager. For example, on Debian-based systems:


sudo apt install qemu-system-x86
# Or
sudo apt install qemu-system-i386

For Arch Linux with audio support, install the PulseAudio package:


sudo pacman -S qemu-audio-pa

Run PRos in QEMU

Launch PRos using the following command, ensuring you have the x16-PRos.img image file:


qemu-system-x86_64 -audiodev pa,id=snd0 -machine pcspk-audiodev=snd0 -fda x16-PRos.img

This command configures QEMU with audio support and boots the PRos image from a virtual floppy disk.

PRos Terminal Commands

The PRos Terminal is a powerful command-line interface for interacting with the OS, supporting commands for disk operations, program execution, and multimedia tasks.

Basic Commands

Command	Description
`help`	Display categorized command reference with navigation
`info`	Show system information and OS details
`cls`	Clear terminal screen
`ver`	Display PRos terminal version
`exit`	Exit to bootloader

System Information

Command	Description
`cpu`	Display detailed CPU information (family, model, cores, cache)
`date`	Show current date (DD/MM/YY format)
`time`	Show current time (HH:MM:SS format, UTC)

File Operations

Command	Syntax	Description
`dir`	`dir`	List files in current directory with size info
`cat`	`cat <filename>`	Display file contents
`size`	`size <filename>`	Show file size in bytes
`del`	`del <filename>`	Delete a file (kernel.bin protected)
`copy`	`copy <source> <dest>`	Copy file (root directory only)
`ren`	`ren <old> <new>`	Rename file (root directory only)
`touch`	`touch <filename>`	Create empty file
`write`	`write <file> <text>`	Write text to file

Text Processing

Command	Syntax	Description
`grep`	`grep <file> <text>`	Search for text in file with line/column highlighting
`head`	`head <filename>`	Display first 10 lines of file
`tail`	`tail <filename>`	Display last 10 lines of file

Directory Operations

Command	Syntax	Description
`cd`	`cd <dirname>`	Change directory (use `..` for parent, `/` for root)
`mkdir`	`mkdir <dirname>`	Create new directory
`deldir`	`deldir <dirname>`	Delete empty directory

Media & Display

Command	Syntax	Description
`view`	`view <file> [-upscale]`	Display BMP image with optional 2x scaling
`chars`	`chars`	Display ASCII character table
`theme`	`theme <name>`	Change color theme (DEFAULT/GROOVYBOX/UBUNTU)

Power Management

Command	Description
`shut`	Shutdown system via APM
`reboot`	Restart system

API Documentation

x16-PRos provides a set of interrupt-driven APIs for developers, organized into three categories, each accessible via a specific interrupt:

INT 0x21: Output API - screen output, colors, cursor, and video mode control.
INT 0x22: File System API - FAT12 file management (list, load, write, delete, etc.).
INT 0x23: String Operations API - strings, input, time/date, cursor, conversions.

Each function is selected via the AH register. Input/output parameters use other registers (e.g., SI, AX, BX, etc.). Unless specified, functions preserve all unused registers and set the carry flag (CF) on error.

Output API (INT 0x21)

Handles screen output in VGA 640×480 16-color mode. All text functions support newline (0x0A) → CR+LF.

Functions

Code (`AH`)	Description	Input	Output / Notes
`0x00`	Initialize Output System	—	Sets VGA mode `0x12` (640×480, 16 colors). No error reporting.
`0x01`	Print String (White)	`SI` = string pointer	Advances `SI`. Color: `0x0F`.
`0x02`	Print String (Green)	`SI` = string pointer	Color: `0x0A`.
`0x03`	Print String (Cyan)	`SI` = string pointer	Color: `0x0B`.
`0x04`	Print String (Red)	`SI` = string pointer	Color: `0x0C`.
`0x05`	Print Newline	—	Outputs `0x0D`, `0x0A`.
`0x06`	Clear Screen	—	Resets video mode (same as `0x00`).
`0x07`	Set Text Color	`BL` = color code (0x00–0x0F)	Sets global color for `0x08`.
`0x08`	Print String (Custom Color)	`SI` = string pointer	Uses color from `0x07`. Advances `SI`.

VGA 16-Color Palette

Code	Name	Hex
`0x00`	Black	`#000000`
`0x01`	Dark Blue	`#0000AA`
`0x02`	Dark Green	`#00AA00`
`0x03`	Dark Cyan	`#00AAAA`
`0x04`	Dark Red	`#AA0000`
`0x05`	Dark Magenta	`#AA00AA`
`0x06`	Brown	`#AA5500`
`0x07`	Light Gray	`#AAAAAA`
`0x08`	Dark Gray	`#555555`
`0x09`	Blue	`#5555FF`
`0x0A`	Green	`#55FF55`
`0x0B`	Cyan	`#55FFFF`
`0x0C`	Red	`#FF5555`
`0x0D`	Magenta	`#FF55FF`
`0x0E`	Yellow	`#FFFF55`
`0x0F`	White	`#FFFFFF`

File System API (INT 0x22)

Manages files on a FAT12 disk (e.g. 1.44 MB floppy). Filenames must be in 8.3 format (e.g. FILE.TXT); case-insensitive (auto-converted to uppercase).

Functions

Code (`AH`)	Description	Input	Output / Notes
`0x00`	Initialize File System	—	Resets floppy controller. `CF` = error.
`0x01`	Get File List	`AX` = buffer pointer	`BX:CX` = total size (32-bit) `DX` = file count Buffer: comma-separated, null-terminated list (e.g. `FILE1.TXT,FILE2.BIN`)
`0x02`	Load File	`AX` = filename `CX` = load address	`BX` = file size. `CF` = error (not found/disk).
`0x03`	Write File	`AX` = filename `BX` = data buffer `CX` = size (bytes)	Creates or overwrites file. `CF` = error.
`0x04`	Check if File Exists	`AX` = filename	`CF` clear = exists, set = not found/invalid.
`0x05`	Create Empty File	`AX` = filename	Fails if exists or root dir full. `CF` = error.
`0x06`	Remove File	`AX` = filename	Deletes entry, frees clusters. `CF` = error.
`0x07`	Rename File	`AX` = old name `BX` = new name	Both 8.3, case-insensitive. `CF` = error.
`0x08`	Get File Size	`AX` = filename	`BX` = size. `CF` = not found.

Limitations: Root directory: max 224 entries. File size: up to 32 MiB (FAT12), though some APIs use 16-bit size fields (≤64 KiB).

String Operations API (INT 0x23)

Utilities for strings, input, and system info. Null-terminated strings assumed.

Functions

Code (`AH`)	Description	Input	Output / Notes
`0x00`	Initialize API	—	No-op (reserved).
`0x01`	Get String Length	`SI` = string pointer	`SI` = length (excl. null).
`0x02`	Convert to Uppercase	`SI` = string pointer	In-place conversion (`'a'–'z'` → `'A'–'Z'`).
`0x03`	Copy String	`SI` = source `DI` = destination	Copies including null terminator.
`0x04`	Trim Spaces	`SI` = string pointer	Removes leading/trailing spaces in-place.
`0x05`	Compare Strings	`SI` = str1 `DI` = str2	`CF` set = equal, clear = not equal.
`0x06`	Compare (Limited)	`SI`, `DI` = strings `CL` = max length	`CF` = equality within limit.
`0x07`	Tokenize String	`SI` = string `AL` = delimiter	`DI` = token pointer (0 = none) `SI` advances past delimiter. Modifies string (inserts `0` at delimiters).
`0x08`	Input String	`AX` = buffer pointer	Max 255 chars. Supports backspace. Ends on `Enter` (`0x0D`).
`0x09`	Clear Screen	—	Same as `INT 0x21, AH=0x06`.
`0x0A`	Get Time String	`BX` = buffer pointer	Writes `HH:MM:SS` (null-terminated).
`0x0B`	Get Date String	`BX` = buffer pointer	Writes `MM/DD/YY`, `DD/MM/YY`, or `YY/MM/DD` depending on global `fmt_date`.
`0x0C`	Convert BCD → Int	`AL` = BCD (e.g. `0x23`)	`AL` = decimal (e.g. `23`).
`0x0D`	Convert Int → String	`SI` = integer	`SI` = pointer to static buffer (up to 7 digits).
`0x0E`	Get Cursor Position	—	`DL` = col, `DH` = row.
`0x0F`	Move Cursor	`DL` = col, `DH` = row	Moves cursor (0-based).
`0x10`	Parse (Space-Separated)	`SI` = string	`SI`, `BX`, `CX`, `DX` = token pointers (0 = none). Modifies string (spaces → `0`).

Program Examples

Below are example programs demonstrating the use of PRos APIs, written in NASM for the 16-bit x86 architecture.

Hello, World

Description: A simple program to output a text string to the terminal.


[BITS 16]
[ORG 0x8000]

start:
    mov ah, 0x01        ; API output print white string function
    mov si, hello_msg   ; String to output
    int 0x21            ; Call the API function
    ret                 ; Return to the terminal

hello_msg db 'Hello, PRos!', 10, 13, 0

Print Colored Strings

Description: A program to output the same string in multiple colors using different API functions.


[BITS 16]
[ORG 0x8000]

start:
    mov ah, 0x01        ; API output print white string function
    mov si, hello_msg   ; String to output
    int 0x21            ; Call the API function

    mov ah, 0x02        ; API output print green string function
    mov si, hello_msg   ; String to output
    int 0x21            ; Call the API function

    mov ah, 0x03        ; API output print cyan string function
    mov si, hello_msg   ; String to output
    int 0x21            ; Call the API function

    mov ah, 0x04        ; API output print red string function
    mov si, hello_msg   ; String to output
    int 0x21            ; Call the API function
    
    ret                 ; Return to the terminal

hello_msg db 'Hello, PRos!', 10, 13, 0

Input name and pring greeting

Description: A program that asks for a name and then displays a greeting using API output and API string.


[BITS 16]
[ORG 0x8000]

start:
    mov ah, 0x01
    mov si, prompt
    int 0x21

    ; Get username input
    mov ah, 0x08          ; API string input string function
    mov si, user_name     ; Buffer
    int 0x23              ; Call the API function

    ; Print newline
    mov ah, 0x05
    int 0x21

    ; ------ Print "Hello + NAME" ------
    mov ah, 0x01
    mov si, hello_msg
    int 0x21

    mov ah, 0x01
    mov si, user_name
    int 0x21
    ; ----------------------------------

    ; Print newline
    mov ah, 0x05
    int 0x21

    ret                   ; Return to the terminal

prompt    db 'Enter your name: ', 0
hello_msg db 'Hello, ', 0
user_name times 32 db 0

x16 PRos — Fast and lightweight

System Lightweight

Rich API

Educational

PRos Terminal

System Requirements

Minimal

Recommended

Maximum

WRITER.BIN

BCHART.BIN

BRAINF.BIN

MINE.BIN

PIANO.BIN

PROCENTC.BIN

SPACE.BIN

CALC.BIN

MEMORY.BIN

PAINT.BIN

PONG.BIN

FETCH.BIN

IMFPLAY.BIN

CLOCK.BIN

HEXEDIT.BIN

And more…

Running

Development Team, contributors and sponsors

PRoX-dev

Qwez-dev

Han Akbe sponsor

Ilnar Karazbaev sponsor

Saeta

Loxsete

Gabriel

Cuzhima

litvincode

Running x16-PRos on Real Hardware

Running x16-PRos on Emulators

PRos Terminal Commands

Basic Commands

System Information

File Operations

Text Processing

Directory Operations

Media & Display

Power Management

API Documentation

Functions

VGA 16-Color Palette

Functions

Functions

Program Examples

Select Image Type

IMG Image