The temptation of every modern system is to guess: detect the hardware, pick the optimal configuration, never bother the user. Castalia DOS does the opposite: at boot it shows you a menu with eight gates. The decision is yours. This is not laziness; it is doctrine.
DOS games do not forgive
A 1993 game that wants EMS will not start without a page frame. Another from 1990 hangs IF that frame exists. Wing Commander wants every last byte of conventional memory; a CD game wants the MSCDEX stack loaded. There is no THE correct configuration: there are correct configurations per task. Any «smart» autodetect gets it right 80% of the time, and the remaining 20% is exactly why a gaming DOS exists.
Compatibility beats elegance
It is the one rule that governs the whole project: when a choice must be made between a prettier design and a game that runs, the game wins. That is why the launcher unloads itself from memory before handing over — the game gets every free byte — why DOS relocates to the HMA when it can, and why the default profile (XMS Gaming) targets the most conventional RAM a game is likely to ask for.
There is no THE correct configuration. There are eight, and you choose at the gate.
C. DI CASTELLO · DEVELOPER LEAD · PRINCETON, IL · 2026.06.20