Building MS-DOS 2.11 today from reconstructed source and tools #VintageComputing
After having good luck with rebuilding core PC DOS 1.1 from source code, Michal Necasek decided to do the same with the DOS 2.11 source code released by the Computer History Museum (CHM). An extensive collection of notes were compiled while banging the released source code into shape. That turned out to be a lot harder than building DOS 1.1 for two reasons.
One is that the released DOS 2.11 source code is a lot more extensive and includes source code for numerous utilities (CHKDSK, DEBUG, EDLIN, SYS, etc.).
The other, bigger reason is that the CHM unfortunately created a bit of a mess when releasing the code and sorting out the pieces was not trivial.
The CHM placed all DOS 2.x related files in just two directories, ‘v20object’ and ‘v20source’. It is now clear that the files came from at least three distinct sources:
MS-DOS 2.00 OEM distribution disks
MS-DOS 2.11 source code of unknown provenance
Miscellaneous debris such as WordStar 3.20 overlay files
I determined that the entire DOS 2.11 source code can be successfully built with MASM 1.25 from 1983, about the same vintage as the source code. Whether that was actually the version used is anyone’s guess at this point, but it easily could have been.
The post is a treasure trove as to how DOS was created for both IBM and for third party providers (OEMs).
Read more in the detailed post on the OS/2 Museum Website.
Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.
Python for Microcontrollers — Python on Microcontrollers Newsletter: Pi Day, GitHub 2FA and much more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi
