4 ms·
OS/2 1.x did switch from protected back to real mode by resetting the CPU, in order to run a single DOS application in the "penalty box". Device drivers even ha
by rep_lodsb 3y ago
OS/2 1.x did switch from protected back to real mode by resetting the CPU, in order to run a single DOS application in the "penalty box". Device drivers even had to be able to run seamlessly in both modes!
That article is paywalled, but what you quoted reads like pure bullshit. PrestoChangoSelector was used in protected mode to make code segments writable, and had nothing to do with DOS compatibility:
https://jeffpar.github.io/kbarchive/kb/089/Q89560/ https://jeffpar.github.io/kbarchive/kb/089/Q89560/