[net.micro.pc] Roland MPU 401 MIDI i/f, PC/AT and INT 2

dyer@spdcc.UUCP (07/14/86)

The issue of hardware interrupts on the PC/AT and compatibility with
boards originally designed for the PC reads its ugly head once again.
The MPU401 generates an interrupt on INT 2, which is used in the AT
as a cascade for a second interrupt controller.  Actually, it *seems*
to work in my AT, perhaps because the software might do some interrupt
shuffling (this is only a guess.)

My question is: is there any harm in having two devices share the same 
hardware interrupt level, provided that the interrupt routine manages
to disambiguate between the originating devices?  How about INT 2, which
I believe is used for hard disk interrupts? 

P.S.: anyone know the IO port addresses of the Roland?
-- 
Steve Dyer
dyer@harvard.HARVARD.EDU
{linus,wanginst,bbncca,bbnccv,harvard,ima,ihnp4}!spdcc!dyer