Lots of resident drivers search for a free interrupt vector starting
from 0x80. Those vectors are free in real dos, but are busy in dosemu.
For example sbmidi.exe refuses to work due to this. The included patch
solves the problem, but I don't know if it is correct to leave *all*
these vectors free.
--- src/base/async/int.c Fri Aug 11 23:05:55 2000
+++ src/base/async/int.c Fri Aug 11 22:37:49 2000
@@ -2225,7 +2225,7 @@
/* don't overwrite; these have been set during video init */
if(i == 0x1f || i == 0x43) continue;
- if ((i & 0xf8) == 0x60) { /* user interrupts */
+ if (((i & 0xf8) == 0x60) || (i > 0x78)) { /* user interrupts */
/* show also EMS (int0x67) as disabled */
SETIVEC(i, 0, 0);
} else {
