GentleOS/16 hobby OS for vintage 16-bit PCs

# GentleOS/32 - Hobby OS for vintage 16-bit PCs Source: [https://luke8086.dev/gentleos16.html](https://luke8086.dev/gentleos16.html) \* Project handcrafted by a human GentleOS/16 is a hobby OS for vintage 16\-bit PCs\. Its minimal requirements are an 8086 CPU and a CGA display capable of 320x200x4 mode\. It's built specifically for tinkering with old hardware on the bare metal, using plain C\. It doesn't have any "practical" use, there's no web browser and no way to run third\-party apps\. It's a simplified version of a slightly more advanced OS for 32\-bit devices \-[GentleOS/32](https://luke8086.dev/gentleos32.html), with which it shares most of its design considerations\.  ## Try in your browser Open this page in a desktop browser to run an online PC emulator [Click here](https://luke8086.dev/gentleos16.html#)to launch GentleOS/16 in an online PC emulator\. ## Gallery ### Devices ### Apps [](https://luke8086.dev/gentleos-assets/images/gentleos16-app-launcher.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-clock.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-calendar.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-calc.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-fonts.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-keys.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-sounds.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-mines.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-pairs.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-mahjong.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-snake.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-tetris.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-freecell.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-klondike.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-bjack.webp)[](https://luke8086.dev/gentleos-assets/images/gentleos16-app-setup.webp) ## Downloads **⚠︎ Warning**: GentleOS/16 is written in good faith, but it's experimental and the author takes no responsibility for any lost data or damaged hardware\. It is free software, licensed under GPL\-2\.0, and comes with no warranty\. Proceed at your own risk\. [gentleos16\.img](https://github.com/luke8086/gentleos16/releases/download/latest-release/gentleos16.img)\- Bootable disk image that can be written to a 1\.44M/720K/360K floppy, HDD or USB flash drive [gentleos16\-fd1440\.img](https://github.com/luke8086/gentleos16/releases/download/latest-release/gentleos16-fd1440.img)\- 1\.44M floppy\-sized image for use in emulators [gentleos16\-fd720\.img](https://github.com/luke8086/gentleos16/releases/download/latest-release/gentleos16-fd720.img)\- 720K floppy\-sized image for use in emulators [GENTLEOS\.COM](https://github.com/luke8086/gentleos16/releases/download/latest-release/GENTLEOS.COM)\- COM executable that can be started from DOS ## Q&A ### Will it run on my PC? Due to quirkiness of old devices, the only way to be sure is to check\. The lowest hardware configuration tested by the author was NEC V20 CPU and 512KB of RAM\. On the high end, the PC must still support BIOS / legacy boot\. It won't work on pure\-UEFI systems\. ### How to debug over serial port? First you need to recompile it with`DEBUG\_TO\_UART`enabled in`config\.h`\. Then, my preferred way is to use[Serial USB Terminal](https://play.google.com/store/apps/details?id=de.kai_morich.serial_usb_terminal)on Android, through a cheap RS232 to USB\-C adapter with PL\-2303 chipset, and a mini null\-modem F\-F adapter\. In the app you need to set 9600 baud rate, 8 data bits, no parity, 1 stop bit\. ### Why are there 64GB pendrives plugged into PCs from the 80s?\! I've replaced the original 720K floppy drives with[Gotek](https://www.gotekemulator.com/)emulators\. They are much more convenient for development, especially since modern USB floppy drives don't work very well with 720K disks\. ### Are the photos real? The screen on my device doesn't look that good\. They're real, taken with an iPhone 16, and lit using a softbox\. Only minor adjustments were done in GIMP \- trimming, white balance, exposure, and contrast\. ### How to contribute? I'm making this project for fun in my spare time and sharing it as\-is\. I don't really accept pull requests because I already have plenty of them to review at work\. However, if you do anything interesting with it, please drop me an email\! Make sure to mention if you're happy with your changes being included in my branch or on the website\. ## Links - [Source code](https://github.com/luke8086/gentleos) - [GentleOS/32](https://luke8086.dev/gentleos32.html)\- Sibling OS for 32\-bit devices - [Thread on HN](https://news.ycombinator.com/item?id=48435943)\(2026\-06\-07\) - [Thread on Lobste\.rs](https://lobste.rs/s/1umrbv/gentleos_pair_hobby_oses_for_vintage_32)\(2026\-06\-08\) Other useful resources: - [OSDev\.org](https://osdev.org/)\- Extensive wiki and forum about OS development - [FreeDOS](https://freedos.org/)\- Actively maintained clone of DOS, the best way to go if you want to do something practical with a very old PC ## License Copyright © 2026 luke8086\. GentleOS/16 is licensed under the[GNU General Public License, version 2](https://www.gnu.org/licenses/old-licenses/gpl-2.0.html)\.