🚀 go-pugleaf

dmurdoch@mast.queensu.ca (Duncan Murdoch) writes:
>>That is, if you do a setvect does does the handler perform in real or
>>protected mode?  Is there any control over doing this (i.e., a real
>>mode handler)?
>
>From what I can spot on a quick read through the BP 7 manual, there's no 
>special support for interrupts.  That is, you'll have to use the DPMI 
>services directly.

I don't know how it is done, but I do know of a serial comm
application being written using BP7 that has dual-mode interrupts
using a shared memory buffer which is accessed by both the real and
protected mode version of the interrupt handler. Depending on which
mode the cpu is in when the interrupt arrives, the DPMI server calls
the same mode handler, so no mode switch is necessary. It makes
performance incredibly fast when running under a 386 memory manager or
under Windows compared to all the usual DOS serial comm programs.

But as I said, I don't have enough knowledge about that level of
programming things or of the Borland Pascal language to be able to say
how much of that is supported by Pascal and how much requires dropping
into assembler language.

 -- sidney <sidney@borland.com>