Re: How-to disable irq4 serial ints

[Stas Sergeev <stsp@aknet.ru>]

Hello.

Hufnus wrote:
> I am afraid that is not exactly true!  It is related
> to dosemu not being 100% DOS compatible, when handling these
> programs of ours.  Because they have been un-crashable for the
> 20 years that they have been shipped to customers on vanilla
> Dos 3.2 - 6.2
This still doesn't mean your progs
are bug-free. Dosemu is not 100%
compatible mostly in the area of
the hardware timings. For example,
you program may assume that after
it unmasks the IRQ on PIC, it can
still execute a bunch of instructions
before the interrupt is received,
but under dosemu the interrupt can
happen immediately because it doesn't
properly emulate the delays of the
hardware. So you can be interrupted
immediately after you did the "out"
instruction that unmasks an IRQ.
This may be called a bug in dosemu,
but the properly written programs
should not rely on such a things
(fortunately most of them do not).

> The hole issue started when we discovered that: after about 20 or
> 30 days of continuous running the dosemu clock date/time would get
> corrupted.
This really sounds like a bug in
dosemu, but unfortunately most people
do not have a resources for running
such a long tests. And since fixing
this will fix also another problem of
yours, it would be nice if you track
this one down on dosemu side:)