By trial and error I discovered EMM calls enable interrupts. This can
cause havoc in a TSR where you need interrupts disabled. Finding these
bugs is not easy. My TSR enables interrupts part of the time, so I do
EMM calls there. Here's an example with comments.

void
next_irq (void)
{
int x;

next:
x = next (); /* service IRQs with */
enable (); /* interrupts enabled */

# ifndef noemm /* EMM call enables interrupts, do */
emm_get_page_map (e1); /* not do it before enable () above */ # endif

if (x) {
service_com_irqs (x);

} else
service_ticktock ();

# ifndef noemm
emm_set_page_map (e1);
# endif

disable ();
if (x)
mask_irq (NO, x);

if (iq[iz])
goto next;
}

* SLMR 2.1a *

* SLMR 2.1a *
---
■ Synchronet ■ Vertrauen ■ Home of Synchronet ■ [vert/cvs/bbs].synchro.net