Thinking that it only made sense to move the EBDA if I was actually going to try the I=A000-B7FF trick, I naively did this in CONFIG.SYS:
0?SWITCHES=/E:1024 0?DEVICE=C:\BIN\JEMMEX.EXE NOEMS 1?DEVICE=C:\BIN\UMBPCI.SYS 1?DEVICE=C:\BIN\XMGR.SYS /W
But SWITCHES is special. It takes effect regardless whether I select option 0 or 1. Reading config.c, the special treatment is by design, although the above use case which doesn't create a catch-22 might not have been considered.
- Make a visible warning or error if the user tries to conditionalize SWITCHES by a menu option. (Maybe it's there already, but the menu blew it away.)
- Document the special treatment of SWITCHES in the help file and in config.txt.
- Correct the documentation of the /E switch to say that the size is in bytes, not in kilobytes.